Effect of the subdose of human chorionic gonadotropin applied in the Hou Hai acupoint on ovulation induction in mares / [Efeito da subdose de gonadotrofina coriônica humana aplicada no acuponto Hou Hai sobre a indução da ovulação em éguas]

The objective of this study was to evaluate the effects of an hCG sub dose applied at the Hou Hai acupoint on corpus luteum (CL) quality and ovulation induction in mares. Fifteen crossbred mares were distributed in randomized blocks and used in three periods with each period employed as the blocking factor in three treatments: T1 = 1500 IU of hCG via intravenous (IV); T2 = 450 IU of hCG applied at the false acupoint (IV); and T3 = 450 IU of hCG applied at the Hou Hai acupoint. Mean diameter of the CL, serum concentration of progesterone (P4), vascularization of the pre-ovulatory follicle and CL were evaluated. Females administered 450 IU of hCG at the Hou Hai acupoint exhibited greater ovulation rates (33.33%) 48h after induction; The minimum number of colored pixel (NCP) of the pre-ovulatory follicle of control females was superior (40.33) to that of mares administered 450 IU of hCG IV at the false acupoint (36.84) and similar to that of those administered hCG at the Hou Hai acupoint (39.31). Further, moderately positive correlations were found between the CL diameter and the P4 concentration on D8 (P<0.05). IV administration of 450 IU of hCG or at the Hou Hai acupoint was efficient at inducing ovulation and ensuring the quality of CL in mares.(AU)

O objetivo foi avaliar os efeitos de uma subdose de hCG aplicada no acuponto Hou Hai na qualidade do corpo lúteo (CL) e na indução da ovulação em éguas. Quinze éguas mestiças foram distribuídas em blocos ao acaso, sendo o período utilizado como fator de blocagem, em: T1 = 1500 UI de hCG por via intravenosa (IV); T2 = 450 UI de hCG aplicado no falso acuponto (IV) e T3 = 450 UI de hCG aplicada no acuponto Hou Hai. Avaliou-se diâmetro médio do CL, concentração sérica de progesterona (P4), vascularização do folículo pré-ovulatório e do CL. As fêmeas que receberam 450 UI de hCG no acuponto Hou Hai apresentaram maiores taxas de ovulação (33,33%) 48h após a indução. O número de pixels coloridos (NPC) mínimo do folículo pré-ovulatório das fêmeas do grupo controle foi superior (40,33) ao das éguas que receberam 450 UI de hCG IV no falso acuponto (36,84) e semelhante ao das éguas que receberam hCG no acuponto Hou Hai (39,31); correlações moderadamente positivas foram encontradas entre o diâmetro do CL e a concentração de P4, ambos no D8 (P <0,05). A administração IV de 450 UI de hCG ou no acuponto Hou Hai foi eficiente na indução da ovulação e na garantia da qualidade do CL nas éguas.(AU)

Effect of lithium chloride on the luteal steroidogenesis in gonadotropin-stimulated rat

Main function of corpus luteum is progesterone synthesis that is significantly accompanied with an increase in levels of mRNA encoding of steroidogenic enzymes known as luteal markers. This study was designed to evaluate effects of lithium chloride on the release of steroid hormones and steroidogenic enzymes in gonadotropin-stimulated rats. Immature 23 days old Wistar rats were divided into 10 groups; each group comprised of 8 rats, and induced with single injection of pregnant mare's serum gonadotrophin [PMSG] and followed by single injection of human chorionic gonadotropin [hCG]. Then, rats were given lithium chloride [LiCl] or saline at 12 hours post-hCG injection. Ovaries were collected in 4-hour interval from 8-24 hour post-hCG injection. Expression pattern of steroidogenic acute regulatory protein [StAR], side-chain cleavage cytochrome P450 [P450scc] and 3beta-hydroxysteroid dehydrogenase [3beta-HSD] genes were determined by semi-quantitative RT-PCR. In addition, serum levels of progesterone and 17beta-estradiol were measured by ELISA. Our results showed that hCG stimulation of progesterone was markedly diminished and transcript levels of key steroidogenic enzymes were altered in the hormone-stimulated rats following LiCl treatment. These results suggest that critical steps in the function of corpus luteum are disrupted by lithium. It is concluded that LiCl is an effective factor for suppressing of steroid genes expression

Luteal lifespan and fertility after estrus synchronization in goats

The present experiment aims to examine the efficiency of estrus synchronization using progesterone and equine chorionic gonadotrophin (eCG) and to look at luteal function. During the non-breeding and breeding season, 5 adult female Korean native goats were injected intramuscularly with 2.5 ml of physiological saline as the control. A progesterone impregnated intravaginal sponge was then kept in the same goats for 10 days followed, after a week, by an intramuscular injection of 500 IU eCG. Five adult female Nubian goats were mated with a fertile buck during the non-breeding season. During the non-breeding season 2 of the 5 goats showed a normal estrous cycle (ranging from 18 to 21 days) and 3 a short estrous cycle (ranging from 3 to 6 days). During the breeding season the equivalent figures were 1 and 2. The major axes of the corpus luteum (CL) were measured by means of calipers built into the ultrasonography system, and the concentrations of plasma progesterone (P(4)) were determined by double antibody radioimmunoassay. The mean major axes of the CL in goats showing the short cycle (6.1 +/- 0.5 mm) was significantly smaller than in those showing the normal cycle (8.9 +/- 0.5 mm; p < 0.01) and also the value of P4 in goats showing the short cycle (4.2 +/- 2.1 ng/ml) was significantly lower than for those showing the normal cycle (10.3 +/- 4.3 ng/ml; p < 0.05) at day 3 following ovulation. Three out of 5 Nubian goats became pregnant but only one goat carried to full term. The present experiment indicated that a combination of progesterone and eCG was effective in inducing estrus, although it resulted in a high incidence of short luteal lifespan. The low kidding rate and high incidence of embryonic loss may be due to the instability of the luteal lifespan.

comparison of intramuscular and intravaginal suppositoar forms of progesterone for supporting the Luteum phase in ART cycles

Up to seventh week of gestation, progesterone secreted from the ovary is necessary to preserve the pregnancy. In the ART cycles GnRH-a is prescribed and oocytes and granulosa cells or retrieved, both causes corpus luteum insufficiency, so corpus luteum should be supported the best way is progesterone prescription. In this research we compare intramuscular and intravaginal suppositoar forms of progesterone for preserve the pregnancy. A prospective cross sectional evaluation on 193 patients was designed. All of them were on IVF or ICSI cycles. The patients were randomly divided into two groups. Intramuscular progesterone was prescribed in 138 and intravaginal progesterone [supp cyclogest] in 54 patients. The outcome of pregnancy was analyzed using statistical trials including t-test and chi-squre. The two groups were similar duo to age - the ethiology causes of infertility - the doses of proscribed HMG ampule - FSH titrago - the number and grade of transferred embryos. The day after HCG presciption until the end the seventh week in the first group [138 patients] intramuscular progestrone [50 mg/bid] and in the second group [54 Patients] supp of cyclogest [400 mg/bid] was presented. The rate of positive pregnancy test, abortion, successful poegnancy in this two groups were similar. Intramuscular or intravaginal progesterone for supporting corpus luteum in IVF or ICSI cycles have the same effect but the intramuscular route is cheaper

Toxicology of Lapachol in rats: embryolethality

Lapachol is a naphtoquinone with therapeutic potential against enterovirus, Chagas disease and is also used as an antimalarial and antiinflamatory agent. In order to study teratogenic potential of Lapachol, pregnant Wistar rats were treated with 0.5 ml of distilled water (control group); 0.5 ml of hydroalcoholic solution (vehicle group) and 10 mg of Lapachol in 0.5 ml of hydroalcoholic solution (treated group) by oral gavage from the 8th to the 12th day of pregnancy. The following variables were observed: maternal body weight on days 1, 6, l5 and 21 and food intake on days 2, 6, 15 and 21 of pregnancy. The number of live and dead fetuses and the sites of resorptions were counted. The ovaries were weighed and the corpora lutea were counted. Data were analyzed by ANOVA-one way, Dunnett test and the chi square test. Significance level test alpha = 0.05. Results have shown that mothers were unaffected but there were a 99.2 percent of fetus mortality, indicative of a strong abortifacient effect of Lapachol in rats

Regulacion de la luteinizacion folicular por un analago de la hormona liberada de gonadotrofinas (GnRH) / Regulation of follicular luteinization by an agonist of gonadotropin-releasing hormone (GnRH)

Tratamientos prolongados con análogos de GnRH son utilizados en la clínica con el objeto de suprimir la secreción endógena de gonadotrofinas, sin embargo estos análogos ejercen un efecto directo sobre el ovario. El objetivo de este trabajo fue estudiar la acción del análogo de GnRH acetato de leuprolide (LA) sobre esteroidogénesis y apoptosis ovárica. Se inyectó LA (1 Mug/rata/día) a ratas prepúberes superovuladas con PMSG/hCG. Se aislaron los cuerpo lúteos por microdisección y se incubaron durante 3 hs con LH (10 ng/ml) o dibutiril AMPc (dAMPc 1 mM). Se midió la progesterona producida observándose una disminución en el grupo LA tanto de la producción basal como en respuesta a LH (Basales = Control C: 96,6 + 9,6; LA: 22,9 + 2,8; LH= C: 145,7 + 4,9; LA: 23,6 + 2.0 ng/ml, p<0,001). En cambio el dAMPc estimuló significativamente en ambos casos (C: 153,9 + 11,8; LA:83,15 + 8,2). El AMPc producido fue menor en cuerpos lúteos del grupo LA y no fue estimulado por LH (Basales= C: 7,29 + 1,6; LA: 1,17 + 0,6; LH = C: 13,2 + 0,4; LA: 2,5 + 0,4 ng/ml, p<0,01). El contenido proteico por cuerpo lúteo fue semejante en los dos grupos. Por otro lado, teniendo en cuenta que en cortes histológicos de ovarios de ratas tratadas con LA encontramos mayor cantidad de folículos atrésicos y menor de cuerpos lúteos, hemos determinado la cantidad de células apoptóticas. Se tomó como criterio la presencia de cuerpos apoptóticos y núcleo en medialuna, detectándose un número mayor en el grupo LA. Este resultado fue confirmado por inmunohistoquímica (TUNEL). Se concluye que LA produce en el ovario una falla en el sistema receptor de LH- adenilato ciclasa y un aumento de la apoptosis celular.

Need of dietary energy at critical implantation time when local ovarian hormones are obligatory for conceptus development.

Role of dietary energy and local ovarian hormones in conceptus development in the rat was evaluated by giving ip injections of estrogen and progesterone under diet restricted and/or dextrose supplemented conditions, using the experimental model of ovarian compensatory hypertrophy. Replacement of estrogen on day 2 and progesterone on day 3 was necessary for conceptus development in the ipsilateral uterine horn after unilateral ovariectomy on day 2. Continuation of progesterone injection up to day 9 improved the percentage of conceptus development. Conceptus development was normal when unilateral ovariectomy was performed after day 2 of pregnancy. Compensatory increases in corpus luteum (CL) volume and the activity of delta 5 3 beta-hydroxy steroid dehydrogenase (3 beta-HSD) in contralateral ovary were observed after unilateral ovariectomy on day 2-4 of pregnancy. However, 70% diet restriction reducing the energy intake (from 90 to 27 kcal/rat/day) abolished the single dose hormone therapy effects in ipsilateral horn conceptus development and also reduced the effects of continued progesterone, percentage of contralateral horn conceptus development, compensatory changes in the CL volume and delta 5 3 beta-HSD activity of the contralateral ovary. However, dietary dextrose supplementation (increasing calorie intake from 27 to 56 kcal/rat/day) significantly improved/restored hormone response for conceptus development, compensatory changes of the CL volume and enzyme activity in contralateral ovary. The results suggest that day 2-3 of pregnancy is the critical time when local ovarian supply of estrogen and progesterone are obligatory for establishment and conceptus development in the rat. During this period adequate mobilizable source of energy is necessary for execution of hormonal message.

Ability of deglycosylated human chorionic gonadotropin (dghCG) to block luteal function and establishment of pregnancy in bonnet monkeys (Macaca radiata).

The ability of deglycosylated hCG (dghCG) prepared by deglycosylation of a clinical hCG (3000 IU/mg) preparation, to block luteal function during regular cycles as well as luteal rescue in simulated and mated cycles of female bonnet monkeys (M. radiata) has been evaluated. The cycle length (C:28 vs E:24 days) and the total progesterone produced during the luteal phase was significantly reduced (by 45%, P < .05) by injecting 450 micrograms of dghCG/day (in split doses) on days 18, 19, and 20 of cycle. At the doses tested the dghCG used did not exhibit any agonistic activity in the female monkey. In a second experiment injection of 200 micrograms of dghCG/day on days 18-20 of cycle blocked the normal response of the luteal tissue to exogenous hCG (10 micrograms of a 12,000 IU/mg preparation) injected on day 23 of cycle. In a third experiment no pregnancies occurred when a group of 5 animals were injected dghCG (450 micrograms dghCG/day) on days 18-21 of their mated cycle. Animals chosen for this study were proven fertile regularly cycling monkeys and these were cohabited with males between days 9 and 14 of cycle. Each of the monkeys was exposed to 3 consecutive treatment cycles. During post-treatment phase 2 out of 3 monkeys exposed to males became pregnant. The study clearly demonstrates that it is possible to block normal luteal function as well as luteal rescue of the female monkey by using dghCG in the right dose and mode.

Effects of prostaglandin F2 alpha and its synthesis inhibitor indomethacin on corporaluteal functions in pseudopregnant rats.

The effects of PGF2 alpha and its synthesis inhibitor indomethacin on corporaluteal (CL) functions were studied in adult pseudopregnant rats. The CL functions were assessed by studying the duration of pseudopregnancy and histological changes in the ovary. Administration of PGF2 alpha (4 mg/kg BW) significantly (P less than 0.001) shortened the duration of pseudopregnancy. Histological examination of ovaries revealed regressed CL. Administration of indomethacin, on the other hand, significantly (P less than 0.001) prolonged the duration of pseudopregnancy. Histological examination of ovaries revealed large and well formed CL, the diameters of which were significantly (P less than 0.05) increased. Administration of indomethacin and PGF2 alpha simultaneously, however, keeps the duration of pseudopregnancy within normal limit. Further, the shortening in the duration of pseudopregnancy by PGF2 alpha alone was completely reversed by exogenous administration of progesterone. Since PGF2 alpha shortens and indomethacin (an inhibitor of PGF2 alpha synthesis) prolongs the duration of pseudopregnancy, it is concluded that PGF2 alpha acts as a luteolytic agent in rats. The mechanism of luteolysis is most likely to be due to decrease plasma progesterone level. An estimation of blood progesterone level after administration of PGF2 alpha to pseudopregnant rats is therefore, suggested.