Survival of mouse embryos after vitrification depending on the cooling rate of the cryoprotectant solution.

The aim of the study was to determine the relationship between the rate of cooling of eight-cell mouse embryos to the temperature of liquid nitrogen (-196 degrees C) and their developmental capacity after thawing on the basis of their ability to leave the zona pellucida ('hatching') during in vitro culturing. Eight-cell embryos were obtained from superovulated female mice and divided into three experimental and one control group. Embryos from the experimental groups were cryopreserved by the vitrification method using ethylene glycol as cryoprotectant. The vitrification protocols used in the study differed in the rate of cooling of the cryoprotectant solution. Embryos from the first group were frozen in conventional 0.25-ml plastic straws, those from the second group in pipetting 'tips', and embryos from the third group, placed in vitrification solution, were introduced dropwise directly into liquid nitrogen. The control group of embryos was cultured in vitro without freezing in a culturing medium in an environment consisting of 95% air and 5% CO2. The developmental capacity of thawed embryos was assessed on the basis of their ability to leave the zona pellucida ('hatching') after three days of in vitro culturing. In the control group 95.1% of embryos 'hatched'. A significantly higher number of embryos that 'hatched' after thawing was observed in the group introduced dropwise directly into liquid nitrogen (60.0%) compared to the group frozen in pipetting 'tips' (37.9%). The group frozen in straws yielded significantly the lowest proportion of 'hatching' embryos (8.1%). These results showed that increasing cooling rates during vitrification of embryos improved their survival.

[Thyroid and ovarian hormones in ewes treated with gestagens and PMSG in the spring season]. / Hormóny stítnej zl'azy a vajecníka u bahníc osetrených gestagénmi a PMSG v jarnom období.

Recent experimental observations have shown that the thyroid gland plays a dominant part in the induction and maintenance of anoestrus in ewes. The mechanisms of the anoestrous effects of the thyroid gland are still unclear. On the basis of experiments, in which after thyroidectomy at the onset of sexual activity LH production was maintained also during the spring months, iodothyronines have been supposed to stimulate the inhibitory effects of oestrogens upon the neuroendocrine centres that generate pulsatile LH secretion (Moenter et al., 1991; Webster et al; 1991). However, in our previous work (Bekeová et al., 1995) we observed significant changes in iodothyronine levels, mainly T3, in ewes treated with FSH, LH-RH and oxytocin-based preparations in 24 and 72 h after parturition in the spring. Having made the above observations we suppose seasonal anoestrus to result rather from changes in thyroid and ovarian hormone interactions or from a decrease in thyroid hormone levels that is induced by a temporary decrease in sexual hormones in this phase of the year. Within investigations into the effects of thyroid hormones and their interactions in spring this study focused on the response of the thyroid gland and ovaries in anoestrous ewes to chlorsuperlutin and PMSG treatment in the second half of May. Eighteen Slovak Merino ewes were divided into an experimental and a control group counting 15 and 3 animals, respectively. The experimental animals were each treated with 20 mg chlorsuperlutin (Agelin Spofa vaginal inserts) for 12 days. On day 12 the inserts were removed and each animal was given 500 IU PMSG. In the same time intervals the controls were treated with a placebo (sterile polyurethane, saline). Blood samples were obtained prior to swab insertion (day 0) and in 4-day intervals under chlorsuperlutin treatment (days 4, 8 and 12). For the first 24 h after PMSG-treatment blood samples were taken in 2-hour intervals and then in 48 and 72 h. For radioimmunological determination of T4, T3, E2 and P4 levels the RIA-test-T4, RIA-test-T3, RIA-test-Estra and RIA-test-Prog commercial kits (manufacturer: URVJT Kosice, Slovak Republic) were used, respectively. When compared to the almost constant but significantly lower T4 values in the controls (P < 0.05; P < 0.01; Tab. II, Fig. 1), a repeated massive release of T4 occurred in the experimental animals (Tab. I, Fig. 1). Its first peak observed 4 h after PMSG was significant in comparison both to Day 0 and the controls (P < 0.05 and P < 0.01, respectively). The same was true for the 2nd peak observed 20 h after PMSG-treatment (P < 0.001 and P < 0.01, respectively). The dynamics of T3 was similar in both groups. The transitory increase in T3 levels observed in the controls (Tab. II, Fig. 2) on day 4 of chlorsuperlutin treatment was insignificant when compared to day 0. Both the decrease observed between day 8 and of chlorsuperlutin treatment and 20 h after PMSG gavage, and the increase between 24 and 72 h appeared to be insignificant. Comparison to day 0 revealed increased T3 levels in the experimental group (Tab. I, Fig. 2) on days 4 and 8 of chlorsuperlutin treatment, the levels of significance being P < 0.01 and 0.05, respectively. Between 8 and 24 h after PMSG-gavage, in contrast to the controls, T3 levels in the experimental animals acquired the character of a slowly increasing rhythmic pulsation. At 72 h after PMSG a significant decrease occurred (P < 0.05). In the control animals (Tab. II, Fig. 3) E2 levels revealed interchanging episodes of insignificant increase and decrease beneath test sensitivity. In the experimental ewes (Tab. I, Fig. 3) a double-peaked elevation of E2 could be observed, the first (insignificant) peak occurring 18 and 20 h and the second (significant) one 48 and 72 h following PMSG treatment (P < 0.05 and 0.01, respectively). The inter-group differences were significant at the level of P < 0.05 in each case.

Accumulation of trace elements in sheep and the effects upon qualitative and quantitative ovarian changes.

The distribution of Cu, Zn, Fe, Mo, Se, As, Cd and Pb was determined in the organs of sheep that died of Cu intoxication from a Cu plants emissions. Simultaneously, quantitative and qualitative changes in the ovaries were evaluated. In sheep that died of copper intoxication, the highest Cu levels were in the liver (1797 +/- 946.1 mg/kg dry matter) and the kidneys (425.5 +/- 426.4 mg/kg dry matter). The liver and kidneys accumulated Zn, whereas Fe was primarily accumulated by spleen and kidneys. Selenium was mainly in the ovaries and uterus (7.72 +/- 4.88 and 5.30 +/- 5.33 mg/kg dry matter respectively). The ovaries and the uterus were the organs that accumulated As, Cd and Pb, respectively. Histological changes in the number of ovarian follicles and the increased occurrence of primary atretic follicles indicated alterations in the membrane structures and organelles of oocytes and in the follicular cells of the stratum granulosum.

[Dynamic changes in hematologic parameters in the blood of sheep during estrus synchronization and in the subsequent early pregnancy]. / Dynamické zmeny hematologických parametrov v krvi oviec pri synchronizácii ruje a v nadväznom case ranej gravidity.

Observation of hematological indices which are a reflection of physiological processes in the individual phases of the reproductive cycle, presents one of the methods of controlling the homeostasis of the ewe's organism. This work focused on the observation of selected indices during synchronization treatment and in the first days of pregnancy The experiment included 10 conventionally bred animals. Blood was obtained from the v. jugularis into an oxalate mixture on days 0 (date of synchronization), 3, 7 and 14 of Agelin implantation, on the day of oestrus and days 7, 14, 17 and 34 of pregnancy. Erythrocyte counts were determined by the Bürker flask method, hemoglobin concentrations by spectrophotometry and packed cell volume (PCV) by the method of Janetzki. For leucocyte count determination the Bürker flask method with Turk's solution was used; the percentual proportion of leucocytes was stated by the leucogram. During synchronization treatment and pregnancy the mean erythrocyte counts ranged from 9.16 +/- 0.81 to 9.74 +/- 0.61 T/l and from 9.09 +/- 0.84 to 9.47 +/- 1.11 T/l, respectively. Hemoglobin concentrations oscillated between 10.71 +/- 1.02 and 11.83 +/- 1.01 g/l. PCV values reached between 32.44 +/- 2.18 and 39.33 +/- 2.73 l/l with a significant increase on day 14 of Agelin implantation and days 17 and 34 of pregnancy (P < 0.05). This dynamics of the red blood components points to the occurrence of functional-morphological changes in the sexual apparatus during oestrus and Agelin treatment. Through mediation by the vascular system a change in the mean values may also occur (Kresan et al., 1979).(ABSTRACT TRUNCATED AT 250 WORDS)

Growth and development of follicles in different phases of the oestrous cycle in cows in relation to the presence of the corpus luteum and an oestrogen-dominant follicle.

In this work recruition and growth of follicles and quality of the largest ones were determined and compared in the individual stages of the bovine oestrous cycle (stages I, II, III and IV - days 1-4, 5-10, 11-17 and 18-21, respectively) in relation to the presence of the corpus luteum and an oestrogen-dominant follicle on the ovary. The maximum proportions of small (< 4.9 mm), medium-sized (5.0-9.9 mm) and large (> 10 mm) follicles were observed in stages IV (93.4%), I (16.6%) and III (4.8%), respectively. The results of our study revealed the presence of the large oestrogen-dominant follicle that have negative effects upon the presence of another large follicle on the ovary and upon the recruition of small (< 4.9 mm) follicles. On the contrary, the presence of a large oestrogen-dominant follicle positively influenced the occurrence of 5-9.9 mm follicles in all stages of the cycle. No effects of the CL were observed upon the presence of medium-sized and large follicles. Although the differences were insignificant, negative effects of the CL were observed in relation to the occurrence of small (< 4.9 mm) follicles.

[Levels of sodium and potassium and their relation to ovarian hormones during estrus synchronization and pregnancy in ewes]. / Koncentrácie sodíka, draslíka a ich vztah k ovariálnym hormónom v case synchronizácie ruje a gravidity bahníc.

The active transport of mineral substances by cell membranes plays an important role in the neurohumoral regulation of reproductive processes in farm animals. A great importance is attributed to lipoproteins as sources of the primary precursor of steroid synthesis in the placenta and ovaries (Knopp et al., 1986; Grummer et al., 1988). The effects of hormones on K metabolism in the blood serum of ewes were studied by Hawk et al. (1961). Krajnicáková et al. (1993) observed the dynamic changes of electrolytes in the course of the reproductive cycle in ewes. Na and K levels and their relation to ovarian hormones were determined in the systemic blood stream of ewes during oestrus synchronization and pregnancy. Ten Slovak Merino ewes aged 3-5 years and weighing 40-50 kg were included in the experiment. The animals were reared conventionally. A feed ration consisted of silage, hay, feeding beet-pulp, straw and in the last two months of pregnancy it was supplemented with roughage. Water and salt were given ad libitum. Blood samples were obtained from the jugular vein prior to synchronization (day 0) and on days 3, 7 and 14 of synchronization with Agelin vaginal implants. After removing the implants the animals received 500 I.U. PMSG (Pregnant Mare Serum Gonadotropin). The animal in oestrus cycle were inseminated with fresh diluted semen. Reinsemination was not performed in this experiment. Sampling was continued on the day of insemination and on days 7, 14 and in month 2, 3, 4 and 5 of pregnancy. Na and K levels were measured by atomic absorbtion spectrophotometry using the Atom Spek device (RANG-HIGLER). Progesterone (P4) and 17 beta-oestradiol (E2) levels were assayed radioimmunologically using the respective kits (RIA-test-PROG and RIA-test-ESTRA) manufactured by URVJ Kosice. During the observation period Na levels fluctuated within 131.50 +/- 1.71 and 153.55 +/- 4.77 nmol/l of serum (Tab. I) and significantly decreased between day 14 of synchronization and the end of the investigation (P < 0.05; P < 0.01; P < 0.001). Potassium levels were observed to significantly decrease from the day of insemination on, throughout the first days of pregnancy and the above-mentioned months of gravidity, the values ranging between 4.57 +/- 0.52 and 3.93 +/- 0.36 nmol/l.(ABSTRACT TRUNCATED AT 400 WORDS)

[Levels of total lipids, cholesterol and progesterone during estrus synchronization and pregnancy in sheep]. / Koncentrácie celkových lipidov, cholesterolu a progesterónu v case synchronizácie ruje a v priebehu gravidity oviec.

Our investigations were concerned with dynamic changes in total lipids (CL), cholesterol (CHOL) and progesterone (P4) in blood serum of sheep in the period of oestrus synchronization treatment and during mating and gravidity. Our experiment was carried out using 10 animals housed under the conditions of productive rearing. Blood samples were taken from v. jugularis on day of swab application (day 0) and on days 3 and 7 of the action of Agelin vaginal swabs, on day of insemination, and on days 7, 14, 17 and in the 2nd, 3rd and 4th month of gravidity. Blood serum was used to determine total lipids and cholesterol by means of Bio-Lachema tests, and P4 concentrations employing RIA-test-Prog kits (URVJT, Kosice). A statistically significant decrease in concentrations of total lipids (Fig. 1, Tab. I) in sheep blood serum was recorded on day of insemination (P < 0.05) compared to day 0, with the value 1.59 +/- 0.31 g/l of serum, and in the 3rd month of gravidity (P < 0.01), at concentrations 1.36 +/- 0.38 g/l of serum. The determined decrease in their values in the mentioned period can be modulated by the mutually changing ratio of steroid hormones or by inhibition of synthesis of lipoproteins responsible for changes in total plasma lipids. Changes in cholesterol concentrations (Fig. 2, Tab. I) during the introduction of swabs were insignificant and ranged from 1.60 +/- 0.42 to 1.73 +/- 0.33 mmol/l of serum. An insignificant increase in cholesterol concentrations (P < 0.05), with its highest levels 1.98 +/- 0.43 mmol/l of serum, was recorded in the 3rd month of gravidity.(ABSTRACT TRUNCATED AT 250 WORDS)

[Alkaline phosphatase during the puerperium in ewes and its relation to thyroid hormones and ovarian steroids]. / Alkalická fosfatáza v puerpériu bahníc a jej vztah k hormónom stítnej zl'azy a ovariálnym steroidom.

Triacylglycerols as the sources of cholesterol, the primary precursor of steroid synthesis, are one of the factors that limit the speed of steroidogenesis. Synthesis and resynthesis of triacylglycerols depend, in addition to other factors, on phosphatid hydrolysis that is controlled during pregnancy by placentary ALP (Sumikawa et al., 1987) and the FFA pool in the systemic blood stream. Enzymes participating in FFA release from the fat tissue are affected by thyroid hormones and TSH (Mayes, 1977). In view of the above facts, this work was aimed at the observation of changes in alkaline phosphatase (ALP), thyroxine (T4), triiodothyronine (T3), 17 beta-oestradiol (E2) and progesterone (P4) levels and their mutual correlations in the systemic blood stream of sheep from the first day after parturition to day 51 p.p. Our attention was paid to the possible delayed effects of placentary ALP and thyroid hormones on the synthesis of ovarian steroids in puerperal ewes. Nine merino sheep were included in the experiment; they lambed in the first decade of February and were kept together with their lambs in a classical sheep-cot on deep litter. The animals were fed according to the Czechoslovak State Standard CSN 46 7070. Blood samples were taken from the v. jugularis from 8 to 9 o'clock a.m. 24 hs (day -1) prior to parturition (a.p.), 36 hs and on days 4, 7, 14, 17, 21, 25, 34, 42 and 51 after parturition (p.p.). As compared with day -1 (2.6 +/- 1.08 mu kat/l), ALP concentrations showed a decrease with minimum values occurring on day 17 (1.34 +/- 0.97 mu kat/l, P < 0.05). T4 concentrations also decreased from day -1 (59.4 +/- 9.69 nmol/l) to day 21 (54.89 +/- 11.06 nmol/l, P < 0.05). A similar decrease (from 1.82 +/- 0.33 nmol/l on day 1 to 0.85 +/- 0.32 nmol/l on day 21) could also be observed in T3 levels. As early as 36 hs p.p., the concentrations of both steroid hormones, E2 and P4, significantly decreased [from 2.45 +/- 0.65 and 9.46 +/- 0.34 nmol/l on day -1 to 0.30 +/- 0.24 and 0.05 +/- 0.08 nmol/l, respectively (P < 0.001)]. Throughout the period of investigation, apart from an unsubstantial increase in E2 values on days 17 and 42 and an episodic increase in P4 levels on day 34, the concentrations of both steroids had the values that were significantly lower than those observed on day -1.(ABSTRACT TRUNCATED AT 400 WORDS)

[Dynamics of changes in the cytological picture of vaginal smears and circulating ovarian hormones during the puerperal period in ewes]. / Dynamika zmien cytologického obrazu posvového steru a ovariálnych hormónov cirkulujúcej krvi v puerperálnom období bahníc.

A postparturient period is characterized by low basal secretion of adenohypophysis gonadotropins with the following appropriate changes in ovarian hormones and their response to the morphology of vaginal epithelium. In this study the dynamics of the cytological picture of vaginal swabs and ovarian hormones 17 beta-oestradiol (E2) and progesterone was investigated in the puerpery of ewes. The objective was to obtain and extend the knowledge of cytological changes in vaginal epithelium and levels of ovarian hormones of ewes after parturition and of their relationships from the first several days after lambing until the 51st day of the period of observation. Vaginal swabs for vaginal cytology were taken from nine ewes on days 1, 4, 7, 14, 17, 21, 25, 34, 42 and 51 after parturition. These swabs were fixed in ether-alcohol 1:1, stained according to the Faltínová-Zidovský method, embedded in Canada balsam and evaluated by differentiation of cells according to Luksh (1953). Blood samples for E2 and P4 determinations were taken from the jugular vein in the same intervals as vaginal swabs. The serum was centrifuged and stored at -18 degrees C until use. E2 and P4 concentrations were determined radioimmunologically, using kits RIA-test ESTRA and RIA-test PROG from URVJT Kosice. A statistically significant decline (P < 0.05) of percentual representation of basal and parabasal cells (Fig. 1, Tab. I) on day 7 after lambing was replaced by their multiplication from day 14 reaching the values of 66.07 +/- 3.95 on day 42. A statistically significant decrease in intermediary flat cells (Fig. 2, Tab. II) was observed on days 14 (P < 0.001), 34 and 42 (P < 0.01; P < 0.001), in comparison with the first day after lambing. An evaluation of intermediary convoluted cells revealed their highest percentage on days 1 and 17 after parturition (34.65 +/- 4.77-20.62 +/- 12.57) and their decline to values in the range of 6.77 +/- 1.46-7.66 +/- 2.25 on the remaining days of the period of observation. Percent occurrence of superficial flat cells (Fig. 3, Tab. I) ranged from 3.9 +/- 1.10 to 10.63 +/- 7.23 from day 1 to day 51 after lambing. The lowest percentual representation (1.32 +/- 0.79-4.10 +/- 1.89) was recorded for superficial convoluted cells. Multiplication of the evaluated cells was observed, reaching the highest but insignificant representation (P > 0.05) on day 25 of postparturient investigation: 4.10 +/- 1.89 (Fig. 3, Tab. I). 17 beta-oestradiol (E2) concentrations were compared to the -1st day before parturition, when its values varied at the level of 2.45 +/- 0.64 nmol/l serum.(ABSTRACT TRUNCATED AT 400 WORDS)

[The effect of repeated administration of carbetocin (Depotocin, Spofa) in the first days postpartum on levels of thyroxine, triiodothyronine, 17 beta-estradiol, progesterone and on fertilization]. / Ucinok opakovanej aplikácie karbetocínu (Depotocin, Spofa) v prvých dnoch po pôrode na koncentrácie tyroxínu, trijódtyronínu, 17 beta-estradiolu, progesterónu a na koncepciu bahníc.

Application of new procedures in the sphere of the control of sexual functions requires an extension of present knowledge of postparturient endocrinium or endogenic factors comprised in postparturient physiology of sexual activity. According to recent data, oxytocin, besides its uterotonic and luteolytic activity, acts as an ovarian factor in the local intrafollicular regulation of stereidogenesis and as a modulator of uterine secretion of prostaglandines. Based on present knowledge of oxytocin effects, this study was aimed at investigation of the influence of repeated carbetocin (Depotocin inj. Spofa) administration on the dynamics of changes in thyroxine (T4), triiodothyronine (T3), 17 beta-estradiol (E2), progesterone (P4) concentrations and their mutual correlations from the 36th hour till the 51st day after parturition. Simultaneous study of a possible delayed influence of applied carbetocin on conception of ewes after oestrus evocation on day 51 after lambing was carried out. Nineteen ewes of the Slovak Merino breed, lambed in the first decade of February, were assigned to the experimental (n = 9) and to the control group (n = 10). Experimental ewes were subjected to repeated postparturient carbetocin treatment at the dose 0.07 mg per animal. The first dose was applied i. m. in 24 hours, and the second in 72 hours after parturition. On day 51 oestrus was induced in nine ewes of each group by combined treatment with chlorsuperlutin (Agelin, vaginal pessaries, Spofa) and PMSG (500 I.U./animal). On the day of PMSG application ewes were housed together with rams for the period of the next six days. Samples of blood were taken 24 hours before parturition (-1st day), up to 36 h after parturition and on days 4, 7, 14, 17, 21, 25, 34, 42 and 51 after parturition. Concentrations of T4, T3, E2 and P4 were determined by commercial kits RIA-test-T4; RIA-test-T3; RIA-test-ESTRA and RIA-test-PROG (URVJT Kosice). Animal of the control group showed variations of T4 concentrations (Tab. I, Fig. 1) at the level of original values (59.4 +/- 9.69 nmol.l-1) up to the 21st day with the exception of temporary drop on day 4 and rise on day 7, insignificant compared to the -1st day. T4 concentrations of the control group displayed an intermittent increasing trend with the statistically insignificant peak after 36 h and on day 17, compared to the -1st day. After the 21st day controls revealed a sustained moderate increase while the experimental ewes displayed a decline of its concentrations until the 51st day.(ABSTRACT TRUNCATED AT 400 WORDS)

[Nuclear volume of cells in the stratum granulosum and theca folliculi interna of the largest dominant and atretic tertiary follicles in sheep during the selection process]. / Objem jadier buniek zrnitej vrstvy a vnútorného puzdra najväcsieho dominantného aj atretického terciárneho folikulu oviec v procese selekcie.

According to available literary data, an increased nuclear volume of endocrine gland cells, various structures of the diencephalon and endocrine ovarial structures could be observed when the respective organs and structures were more active; a decreased nuclear volume was revealed when the activity of the respective organ or its structure was suppressed (Mess, 1962; Maracek and Arendarcik, 1976, 1978). Attention was paid to the karyometric analysis of follicular cells of the stratum granulosum (SG) and secretory cells of the theca folliculi interna (TFI) during selection of the dominant ovulatory follicle (DOF). The aim of this study was to determine differences in hte nuclear volumes of the granulosa follicular cells and the secretory cells of the inner theca of the DO1F in comparison with the largest atretic follicles (AF) as well as to verify the use of karyometric variance analysis for the evaluation of the selection process of the dominant ovulatory tertiary follicle. Histological sections were prepared from large DOF and AF from the ovaries of 18 sheep aged 3-5 years and held under standard conditions of a controlled herd. Control group I (n = 3) consisted of Wallachian sheep on day 15 of the sexual cycle (day 0). Excisions of ovaries from the animals of the experimental group (n = 3) were made on day 16 of the cycle after i.m. treatment with 120 micrograms GnRH 10 and 7 hours prior to sampling. Control group II (n = 3) consisted of Tsigai sheep at the 9th or 10th day of the oestrous cycle (hour 0) and three experimental groups (n = 3 each) consisted of Tsigai sheep 24, 48 and 72 hours after i.m. treatment with 125 micrograms cloprostenol. After excision the ovaries were fixed in neutral formaline, cut into 4 mm thick transverse segments and subjected to standard histological processing. After staining with Harris' HE the 5-7 microns thick sections were karyometrically evaluated at a magnification of 2200 x according to the method of Palkovits (1961) using the PC programme Karyotest 03 (Maracek et al., 1991). 200 cells were evaluated from each sample and both cell types; altogether 7200 cells were examined. GnRH treatment (Dirigestran inj. Spofa) increased the nuclear volume of follicular cells (SG) in the dominant ovulatory follicle in the process of selection (Tab. I, Fig. 1). The former, however, reduced the nuclear volume not only of the SG follicular cells of LAF (Tab. II, Fig. 2) but also of the secretory cells of both the DOF and AF theca interna (Tab. II, Figs. 3, 4). Cloprostenol treatment (Oestrophan inj. Spofa) affected the follicular cells of the granulosa in the dominant ovulatory follicle.(ABSTRACT TRUNCATED AT 400 WORDS)

[Dynamics of changes in the serum levels of cholesterol, thyroid and ovarian hormones in the postpartum period in ewes]. / Dynamika zmien koncentrácie cholesterolu, tyroidných a ovariálnych hormónov krvného séra v postpartálnom období bahníc.

Postparturient anoestry, spontaneously changing over to seasonal anoestry, represents an important reserve of full utilization of the reproductive potential of sheep. In spite of the fact that the length of gestation in sheep only amounts to 148 days (+/- 5 days), inability of most sheep to enter the cycle during the spring season acts as a factor limiting the number of lambings--and at the same time production of lambs--to one lambing per year. In order to obtain more detailed knowledge of hormonal conditions in sheep puerpery, the presented work was directed at the study of dynamic changes in concentrations of thyroxine (T4), triiodothyronine (T3), 17 beta-estradiol (E2), progesterone (P4) and cholesterol (Chol) in the blood serum of ewes and at their mutual correlative dependences between the 36th hour and the 51st postparturient day. The observation was carried out in nine nursing ewes of the Slovak Merino breed, with average weight 40-50 kg, lambed in January and February. Blood was sampled by means of jugular vein puncture 14 days (-14th day) before parturition (a. p.), up to 36 h after parturition (p. p.) and on day 4, 7, 14, 17, 21, 25, 34, 42 and 51 p. p. In the period from the 36th h to day 21 p. p., concentrations of T4 (Tab. I, Fig. 1) showed a decreasing tendency compared to the starting -14th day (69.55 +/- +/- 0.12 nmol.-1) with the exception of a temporary increase on the 7th day p. p. The lowest values were recorded on days 4 and 21 p. p. (45.66 +/- 21.61 nmol.l-1, P less than 0.05 and 54.89 +/- 11.06 nmol.l-1, P less than 0.05, resp.). An increase of these values to the starting level was observed between days 25 and 51 p. p. Compared to the values on -14th day (0.76 +/- 0.22 nmol.l-1), a significant increase of T3 concentrations (Tab. I, Fig. 2) was recorded at the 36th h and on days 4 and 7 p. p. with the highest values (1.48 +/- +/- 0.34 nmol.l-1, P less than 0.001) at 36 h p. p. After the temporary decrease between days 14 and 21 p. p. its concentrations showed a constantly rising tendency statistically significant on days 34, 42 and 51 p. p., compared to the -14th day (P less than 0.05). Concentrations of E2 (Tab. I, Fig. 3) reached the values of 0.44 +/- 0.41 nmol.l-1 on the -14th day.(ABSTRACT TRUNCATED AT 400 WORDS)

[Biometric parameters of the uterus and ovaries in sheep after administration of Depotocin inj. Spofa in early puerperium]. / Biometrické parametre maternice a vajecníkov po aplikácii Depotocinu inj. Spofa v ranom puerpériu oviec.

Objectivisation of the physiological course of puerpery and control of involution processes of uterus represent topical questions of an increased frequency of lambing. Our study was directed at the determination of the weight, length of body and horns of uterus as well as of the weight, length, width and height of ovaries, following the administration of carbetocin (Depotocin inj. Spofa), in the puerperal period of Slovak Merino sheep. The study was aimed at obtaining objective biometric data on uterus and ovaries and recording the influence of carbetocin on the involution of uterus and ovaries of sheep. Thirty ewes, divided into two groups, were included in the experiment. The animals of the experimental group (n = 15) were subjected to treatment with carbetocin (Depotocin inj. Spofa) at the amount 2 x 0.07 mg. The first dose was applied intramuscularly (i. m.) on the 2nd day after parturition and the second dose was injected subcutaneously (s.c.) on the 4th day after lambing. The second group (n = 15) served as a control. Three ewes (n = 3) were bled on each of the following days: 1, 7, 17, 25 and 34 after parturition. After bleeding the sexual organs were removed by excision and their weight and the length of the body and horns of uterus and of ovaries was determined. The number and size of follicles were determined on the surface of ovaries. The weight of uterus body showed a declining tendency in sheep of the control group with a statistically significant decrease from the 17th till the 34th day after parturition (P less than 0.01). Its weight varied from 56.0-14.6 to 5.2-0.3 g in the above-mentioned time interval. The experimental group showed a statistically significant decrease in weight as early as on the 7th day after lambing compared to the 1st day after parturition, down to the values 185.66-38.91 g (P less than 0.05). The decrease in the weight of uterus body recorded on day 17 (106.56-41.08 g) was less pronounced than in the control group. The final average weight of the body of uterus on the 34th day after parturition was 41.36-8.52 g, that means higher than in the control group (5.2-0.3 g). The weight of gravid horns in the experimental group declined significantly as early as on the 7th day after parturition to the average weight of 60.89-9.45 g and reached 9.86-3.49 g on the 34th day.(ABSTRACT TRUNCATED AT 400 WORDS)

[The effect of synchronization on estrus and pregnancy in sheep and on levels of thyroxine, triiodothyronine, 17 beta-estradiol, progesterone and cholesterol]. / Vplyv synchronizacného osetrenia v sezónnom období a v gravidite oviec na koncentrácie tyroxínu, trijódtyronínu, 17 beta-estradiolu, progesterónu a cholesterolu.

Knowledge of pathogenesis of sexual dysfunctions at altered thyroid activity is limited by the knowledge of multiple and ubiquitous action of its hormones throughout the organism. One of the possibilities of modulatory influence of thyroid hormones on sexual functions can be realized through the participation of thyroxine and triiodothyronine in the synthesis and metabolism of primary substrate of steroid synthesis--cholesterol. The presented work is aimed at the study of simultaneous dynamic changes of concentrations of thyroxine (T4), triiodothyronine (T3), 17 beta-estradiol (E2), progesterone (P4) and cholesterol (Chol) during synchronization of the rutting period and gravidity at parallel correlative evaluation of mutual relations of the followed parameters in ten Merino sheep in the seasonal period. Synchronization was achieved by chlorsuperlutin (Agelin--vaginal swabs, Spofa; 20 mg of chlorsuperlutin/swab) and PMSG (500 I. U./animal). Blood was sampled by means of a jugular vein puncture at the time of swab insertion (-13th day) and after three (-10th day) and seven (-7th day) following days, at the removal of swabs and application of PMSG (-3rd day), on the day of insemination (zero day), on the 7th, 14th and 17th day and in the middle of the 2nd, 3rd, 4th and 5th month of gravidity. In the phase of oestrus synchronization a significant increase of E2 concentrations on days -7 and -3 of the experiment (0.47 +/- 0.079 and 0.542 +/- 0.177 nmol.l-1 of serum, P less than 0.001; P less than 0.001) was observed compared to the E2 values on day -13 (0.084 +/- 0.036 nmol.l-1 of serum). Parallel to these observations, marked intermittent changes of T4 (Tab. I, Graph 1) were recorded with the lowest values of this parameter observed on days -10 (41.75 +/- 20.23, P less than 0.05) and -3 (50.22 +/- 18.77, P less than 0.05) and the highest on day -7 (96.77 +/- 17.51 nmol.l-1, P less than 0.01) and day zero (85.40 +/- 19.59 nmol.l-1 of serum, P less than 0.05) in comparison with the -13th day (67.22 +/- 18.29 nmol.l-1 of serum). Concentrations of P4 (Tab. I, Graph 4) declined to the lowest values on day zero observation (0.09 +/- 0.08 nmol.l-1 of serum, P less than 0.05 vs 3.40 +/- 3.61 nmol.l-1 on day -13). No significant changes of concentrations of T3 (Tab. I, Graph 2) and Chol (Tab. I, Graph 5) were observed during oestrus synchronization. During gravidity, concentrations of E2 (Tab. I Graph 3) showed an increasing trend compared to the -13th day.(ABSTRACT TRUNCATED AT 250 WORDS)

[Biometric parameters of the uterus, ovaries and levels of 17 beta-estradiol (E2) after delivery in sheep]. / Biometrické parametre maternice, vajecníkov a koncentrácie 17 beta-estradiolu (E2) po pôrode oviec.

Biometric changes of uterus, ovaries, follicles and 17 beta-oestradiol (E2) concentrations were investigated in 15 lambing ewes of the Slovak Merino breed in the puerperal period. The sex organs were excised immediately after bleeding from ewes slaughtered on days 1, 7, 17, 25 and 34 post partum (p. p.). Biometric parameters of the body and horns of uterus were measured by a calliper. The ovaries were weighed on an analytical balance, their length, width and height were measured at the same time. The size and number of follicles were determined on the ovary surface. The blood for E2 detection was collected from vena jugularis three and one day before delivery (days -1, -3). Blood samples were also collected after delivery on days 1, 7, 17, 25 and 34. E2 concentrations in the blood serum of ewes were determined by RIA-test-ESTRA kits, designed in one institute at Kosice. The highest weight of uterus body in the test ewes was recorded on day 1 p. p. In the following days the weight of uterus body had a decreasing trend. There were significant differences in the weight of uterus body from day 17 to day 34 p. p., in comparison with the first day after lambing (P less than 0.01). A significant decrease in the length of uterus body was observed from day 17 to day 34 of observation (P less than 0.01; P less than 0.001). An increase in the length of a nongravid horn, observed on day 7 p. p., was followed by a gradual decrease until day 34, similarly like in its weight. No statistically significant differences were found out in the ovary length, width and height. Neither were any greater changes recorded in the weight of ovaries from day 1 to day 34 after delivery. The highest number of small structures (28) observed on day 7 p. p. in the ipsilateral ovary was decreasing in the course of puerperium and the number of follicles larger than 2, 4 and 5 mm was increasing. The highest concentrations of E2 were not recorded on day -1 before delivery. The significantly lowest concentrations of E2 were recorded on day 25 p. p. The above-mentioned results are preliminary and they enlarge the knowledge of biometric parameters of uterus, ovaries, follicles and E2 concentrations after delivery in ewes.

[The effect of steroidal dominance on cAMP, cGMP, progesterone and 17 beta-estradiol levels in the fluid of the largest follicle]. / Vplyv steroidnej dominancie na koncentrácie cAMP, cGMP, progesterónu a 17 beta-estradiolu v tekutine najväcsieho folikulu.

Concentrations and mutual correlations of the cyclic adenosin monophosphate (cAMP), quanosin monophosphate (cGMP), progesterone (P4) and 17-beta-estradiol (E2) were studied in the fluid of the largest follicles in cows, in dependence on the steroid dominance: estrogen-dominant (ED), progesterone-dominant (PD) follicles. Mean cAMP and cGMP concentrations in the follicular fluid in the estrogen-dominant follicles were significantly higher than in the progesterone-dominant follicles; in both cases at P less than 0.01. Significant positive correlation between cAMP and cGMP at P less than 0.001 was stated in the evaluation of the correlations. The cAMP and cGMP concentrations were in significantly negative correlations with the P4 concentration at P less than 0.05, or P less than 0.01 and in significantly positive correlations with the E2, at P less than 0.05. The stated correlations suggest a close mutual relation between cyclic nucleotid and E2, or P4 when the follicles' quality changes.

[Changes in blood levels of progesterone, triiodothyronine and thyroxine and the results of quantitative histological analysis of the placentoma and corpus luteum in cows after prolonged labor]. / Zmeny koncentrácie progesterónu, trijódtyronínu a tyroxínu v krvi a výsledky kvantitatívnej histologickej analýzy placentómu i zltého telieska kráv po protrahovanom pôrode.

Changes in the cell structure of the placentoma and the corpus luteum were subjected to quantitative histological investigation, parallel with the examination of the concentrations of progesterone (P4), triiodotyronine (T3) and tyroxin (T4) during parturition (Oth hour) and two and six hours after parturition. The hormone concentrations were determined by the RIA method. The results of the quantitative histological analysis of the placentomae and the corpus luteum suggest that when the placenta is retained there is a significantly higher number of maintained epithelial cells in the placentoma crypts and a higher number of unchanged small, dark and large, light lutein serraetion cells in the biopsy of the corpus luteum during the period under investigation. The morphological finding significantly correlates with higher concentrations of P4 in the blood of the cows with retained placenta, as compared with those whose placenta was not retained. It can be derived from the pattern of changes in T3 and T4 concentrations, compared with P4 and with the histological finding, that there is a functional relationship between the placentoma, corpus luteum, and the thyroid gland.

[Serum levels of progesterone and estradiol in relation to tertiary follicles in the sheep ovary in proestrus and after administration of gonadoliberin]. / Koncentrácia progesterónu a estradiolu krvného séra vo vztahu k terciárnym folikulom vajecníka oviec v proestre a po podaní gonádoliberínu.

Changes in progesterone (P4) and 17 beta-estradiol (E2) concentrations in blood serum as well as changes in counts and quality of tertiary follicles on ovary surfaces of ewes were investigated after administration of different GnRH doses on the 15th and 16th day of the oestral cycle. Progesterone (P4) and 17 beta-estradiol (E2) were determined by radioimmunological assays using RIA-test-Prog and RIA-test-Estra kits. It follows from the results that GnRH in Dirigestran inj. Spofa preparation reduces the E2 concentration and multiplication of the number of selected tertiary follicles of ovaries through stimulation of their growth and ripening in ewes of the Improved Wallachian breed. The greatest number of ovulations was reported in ewes administered three doses of the preparation. A positive correlation (r = 0.803) was found between the E2 concentration and the number of selected tertiary follicles of ewes in proestrus. The results corroborated the data on a pulsatile release of gonadoliberin during pre-ovulation incretion of gonadotropins--mainly lutropin (LH), as well as the inhibiting effect of gonadoliberin on the steroidogenesis of the ovary--mainly on estradiol production.

[Changes in surface follicles and ovarian weight in testing for responsiveness in dairy cows after induction of superovulation using PMSG and cloprostenol]. / Zmeny povrchových folikulov a hmotnosti vajecníkov pri testovaní responzibility dojníc po indukcii superovulácie PMSG a cloprostenolom.

We evaluated the ovaries of 34 cows cross-bred of the Slovak Pied and Lowland Black-pied breeds which were culled and intended for slaughter during the winter type of feed rations. For superovulation treatment we used PMSG in the preparation Serum Gonadotropin (Bioveta, Nat. Ent., Ivanovice na Hané) and cloprostenol in the preparation Oestrophan inj. Spofa. We weighed the excised ovaries, fixed them in formalin 10% and made a quantitative evaluation of the surface follicles and differentiated them into recruited and selected or dominant follicles. We determined the concentration of 17 beta-estradiol and testosterone with the aid of the 3H RIA set from the firm Sorin after extraction by diethylether with separation of free and bound hormone with active charcoal. 72 hours after the giving of cloprostenol 43% reacted positively to superovulation treatment and after seven days a 50% positive response was recorded. After a dose of 2000 i. u. of PMSG (n = 6) embryo was obtained, whereas after 3000 i. u. of PMSG (n = 8) we flushed out eight embryos, of which four zygotes were suitable for transfer. After a higher dosage of PMSG there was an increase in the average weight of the ovaries, in right-hand ovaries significantly with P less than 0.05. After super-ovulation treatment the concentration of 17 beta-estradiol (E2) in the follicular fluid from follicles seven days after insemination was found to be so low as to be below the limit of detection, with the exception of four samples (mean = 8.60 nmol.l-1). The greatest concentration of E2 was from animals (n = 5) 72 hours after the giving of cloprostenol--1099.61 nmol.l-1) of follicular fluid. The concentration of testosterone was lower in the follicles of untreated cows in the follicular phase (mean = 5.92 nmol.l-1) compared with the follicles of super-ovulated animals the seventh day after insemination (mean = 14.12 nmol.l-1). The number of recruited and especially selected surface antral follicles 72 hours (n = 7) after the giving of cloprostenol and seven days (n = 8) after insemination was significantly higher in the group of brood cows reacting positively to superovulation in comparison with the animals which did not respond. It appears that the simultaneous monitoring of hormonal and morphological changes in the follicular system will help in objectivising the evaluation of the functional activity of stimulated follicles.

[Levels of thyroxine, beta carotene and vitamin A during successful and unsuccessful insemination of heifers]. / Koncentracie tyroxínu, beta karoténu a vitamínu A pri úspesnej a neúspesnej inseminácii jaloviíc.

We studied the concentrations of thyroxine (T4), beta-carotene and vitamin A (vit. A) on the day (zero-th day) of the first successful and unsuccessful insemination of 63 heifers that were administered feed rations balanced according to the Czechoslovak standard CSN 46,7070, housed all the year round, inseminated at uniform time (8:00-9:00 a. m.) and with blood samplings at uniform time (10:00-12:00 a. m.). In the repeat-breeder heifers during the first insemination the above parameters were determined in the same conditions on the day of their second, or third successful and also unsuccessful insemination; the changes relevant to the first insemination were evaluated. In relation to the day of the first successful insemination, we recorded a significant increase in T4 concentration (P less than 0.001; P less than 0.001) on the day of the second, or third successful inseminations. During the second insemination we recorded significantly lower T4 concentrations in the cows which had failed to be inseminated in comparison with successfully inseminated cows; these concentrations did not differ significantly from T4 concentrations in the heifers that failed to become pregnant in the first insemination. Parallelly with the rise in T4 concentration, beta-carotene concentrations also increased during the second and third inseminations (P greater than 0.05). No difference was recorded in beta-carotene concentrations after the first and second unsuccessful inseminations.(ABSTRACT TRUNCATED AT 250 WORDS)