Final follicular maturation by administration of GnRH agonist plus HCG versus HCG in normal responders in ART cycles: an RCT

Background: Gonadotropin-releasing hormone agonists [GnRH-a] was increasingly used for triggering oocyte maturationfor the prevention of ovarian hyperstimulation syndrome. Studies suggest that GnRH-a might be used as a better trigger agent since it causes both Luteinizing hormone and follicle stimulating hormone release from a physiologic natural cycle

Objective: The aim of this study was to evaluate the effect of dual-triggering in assisted reproductive technology outcomes

Materials and Methods: 192 normal responder women aged

Results: The mean of retrieved oocytes and obtained embryos were statistically higher in the dual-trigger group [group I], but the implantation and pregnancy rates were similar in two groups

Conclusion: The results of our study did not confirm the favorable effect of dual-triggered oocyte maturation with a GnRH-a and a standard dosage of hCG as an effective strategy to optimize pregnancy outcome for normal responders in GnRH-antagonist cycles. We think that this new concept requires more studies before becoming a universal controlled ovarian hyperstimulation protocol in vitro fertilization practice

Differential response to sustained stimulation by hCG & LH on goat ovarian granulosa cells.

Background & objectives: Chapekar established a model of ovarian tumourigenesis in mice by splenic transplantation of ovaries, resulting in sustained luteinizing hormone (LH) levels because of absence of feedback inhibition. There is increasing evidence of the differential response to LH or hCG under various experimental conditions. The effect of sustained hormonal stimulation in long term cultures is sparsely investigated. The study is aimed to determine the role of hCG and LH stress on caprine ovarian granulosa cells and their downstream signaling in short and long term cultures. Methods: To study the response of hCG and LH stress and downstream signaling, short term cultures were set up by exposing goat ovarian granulosa cells in primary cultures to hCG and LH stress (levels beyond their physiological doses) for 5 days (P0). Cells were sub-cultured at sixth day and subjected to prolonged LH/ hCG stress for two weeks in passage 1(P1) (long term cultures). Downstream cell signaling molecules were assessed. Intracellular cAMP was estimated by ELISA. For PKA and PKC, activity assays were performed. pERK protein expressions in short term cultures were assessed by Western blot and flowcytometry; in long term cultures, pERK expression was analyzed by flowcytometry. Results: Differential effects on cell proliferation were observed in long term cultures, where the untreated and hCG exposed cells showed markedly reduced cell proliferation after second week of exposure while LH treated cells continued to proliferate. Different levels of cAMP, PKA, PKC and phosphorylated ERK1/2 were observed on short term and long term LH stimulation. On sustained hormonal stimulation, cAMP levels were significantly (P<0.05) higher in hCG treated cultures as compared to controls and LH treated cultures. LH led to maximal elevation of ERK in long term cultures. Interpretation & Conclusions: As pERK1/2 promotes cellular proliferation, activation of ERK1/2 in LH treated cultures may be responsible for sustained growth. Prolonged LH treatment promoted growth and proliferation in caprine ovarian granulosa cells whereas prolonged exposure to hCG led to elevated levels of cAMP and decreased the rate of proliferation. Defining the signals and second messengers that act as survival or apoptotic mediators may help in elucidation of the mechanisms controlling proliferation or programmed cell death in granulosa cells.

Effects of echinomycin on endothelin-2 expression and ovulation in immature rats primed with gonadotropins

Echinomycin is a small-molecule inhibitor of hypoxia-inducible factor-1 DNA-binding activity, which plays a crucial role in ovarian ovulation in mammalians. The present study was designed to test the hypothesis that hypoxia-inducible factor (HIF)-1alpha-mediated endothelin (ET)-2 expressions contributed to ovarian ovulation in response to human chorionic gonadotropin (hCG) during gonadotropin-induced superuvulation. By real-time RT-PCR analysis, ET-2 mRNA level was found to significantly decrease in the ovaries after echinomycin treatment, while HIF-1alpha mRNA and protein expression was not obviously changed. Further analysis also showed that these changes of ET-2 mRNA were consistent with HIF-1 activity in the ovaires, which is similar with HIF-1alpha and ET-2 expression in the granulosa cells with gonadotropin and echinomycin treatments. The results of HIF-1alpha and ET-2 expression in the granulosa cells transfected with cis-element oligodeoxynucleotide (dsODN) under gonadotropin treatment further indicated HIF-1alpha directly mediated the transcriptional activation of ET-2 during gonadotropin-induced superuvulation. Taken together, these results demonstrated that HIF-1alpha-mediated ET-2 transcriptional activation is one of the important mechanisms regulating gonadotropin-induced mammalian ovulatory precess in vivo.

Effect of human chorionic gonadotropin (hCG) on expression of vascular endothelial growth factor a (VEGF-a) in human mid-secretory endometrial cells in three-dimensional primary culture.

Several lines of evidence suggest that human uterine endometrial cells can bind human chorionic gonadotropin (hCG) which, in turn, influences the physiology of implantation stage endometrium. Vascular endothelial growth factor (VEGF) appears to be a candidate mediator in this process. However, our knowledge about hCG action on VEGF in human endometrial cells is very thin. In the present study, we have examined microscopically hCG binding to dissociated human endometrial cells collected from mid-luteal phase and maintained in three-dimensional primary co-culture on rat-tail collagen type I biomatrix and examined the effect of different concentrations (0, 1, 10, 100 and 1000 IU/ML) of hCG on VEGF expression and secretion by endometrial cells maintained in the above system. We report that both cytokeratin positive epithelial cells as well as vimetin positive stromal cells from human mid luteal phase endometrium could bind hCG and that their number increased (P < 0.01) steadily with time. Administration of hCG enhanced (P < 0.05) immunoreactive VEGF protein expression in dose dependent manner in endometrial cells retrieved from mid-luteal phase of cycle, and co-cultured in a three-dimensional cell culture system, but with no marked change in VEGF secretion. Collectively, it appears that hCG influences VEGF protein synthesis in human midluteal phase endometrial cells, but has little effect on post-translational regulation and secretion. From physiological homeostasis point of view, it is likely that synthesis and secretion of VEGF exhibits a modular and factorial regulation to achieve a fine tuning of this potent vasotropic agent in receptive stage endometrium.

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.

Galanin stimulates hCG induced testicular steroidogenesis in adult but not in immature male rats.

The present study was undertaken to understand the role of galanin on testosterone secretion. Leydig cells from adult (60-80 days old) and immature (21-30 days old) rat testis were incubated with galanin (100 nM), galantide (100 nM) and Human Chorionic Gonadotropin (hCG, 25 I.U.) alone or in combinations and testosterone release was measured. It was observed that in adults, galanin failed to alter the basal testosterone release from the dispersed Leydig cells but potentiated the hCG induced testosterone release significantly. While galantide, prevented this galanin potentiating effect, but it did not alter the hCG alone induced testosterone release. On the other hand, the Leydig cells obtained from immature male rats were sensitive to hCG alone but not to galanin or galantide, both of which failed to alter the hCG induced testosterone release from these cells. Based on these results it can be postulated that galanin's role at the level of the male gonad is age dependent since its potentiating effects on hCG induced testosterone release were visible only in the adult and not in the immature male rats.

The Regulators of VEGF Expression in Mouse Ovaries

The objectives of this study were to explore whether ovarian vascular endothelial growth factor (VEGF) expression in mice can be regulated by IL-6 (interleukin-6), angiotensin II, FSH, and hCG; and to test whether the mouse ovarian VEGF expression can result in angiogenesis. The ICR mice were sacrificed, and their ovaries were recovered. Recovered ovaries were treated with IL-6, angiotensin II, FSH, and hCG separately and incubated for 24 hours in alpha-MEM. Expression of mRNA and protein of VEGF were assessed by RT-PCR and immunohistochemistry. The resulting angiogenesis was evaluated through immunohistochemical analysis for CD34. Treatment of mice ovaries with IL-6, FSH, and hCG resulted in a significant increase of VEGF mRNA, and IL-6 was the most potent inducer of VEGF. IL-6 and FSH resulted in increased neovascularization in the follicular phase of mouse ovaries. In contrast, angiotensin II could not increase VEGF expression or neovascularization. We documented an in vitro increase in VEGF expression by IL-6, FSH, and hCG; and reaffirmed that the proliferative response of murine ovarian endothelial cells paralleled an increase of VEGF expression.

Aspectos subcelulares de la inervacción de las células intersticiales del ovario de embrion de pollo cultivado con LH o h CG / Subcellular aspects of interstitial cells innervation in chick embryo ovari cultured with LH or hCG

Diversos autores han demostrado el efecto de LH y hCG sobre la secreción esteroidea del ovario del embrión de pollo. Sin embargo, no se ha investigado el efecto de las hormonas luteinizante y gonadotrofina coriónica humana sobre su inervación. El propósito del presente trabajo fue estudiar los aspectos subcelulares de la inervación de las células intersticiales de ovarios de embrión de pollo cultivados con LH o hCG. Explantos de ovarios izquierdo (funcionante) y derecho (regresivo) de 14 embriones de pollo de 7, 11, 15 u 19 días de desarrollo in ovo de raza Cobb's White Rock fueron cultivados por separado durante 4 días en : 1 - Medio básico (contro); minimun essential medium (MEM-GIBCO)CON 10 de suero fetal bovino, 2-Medio básico con el agregado de LH o hCG (problemas). Los ovarios fueron seccionados en trozos de 2 a 3 mm de diámetro, lo que permitió realizar aproximadamente 30 cultivos de cada ovario. Controles: las características de las células intersticiales y la aparición de las fibras y terminaciones nerviosas observadas en los explantos de ambos ovarios 11 días cultivados durante cuartro días eran similares a los 15 días "in ovo". Problemas: con LH o hCG las fibras y terminaciones nerviosas fueron observadas en el ovario derecho y la médula del ovario izquierdo de 7 días cultivados durante cuatro días, en íntimo contacto con las células intersticiales productoras de esteroides. El presente estadio se correspondía con los 11 días de desarrollo "in ovo"Estos hallazagos sugieren que la inervación de los ovarios estaría controlada por un mecanismo indirecto vía hipotálamo-hipoficiario y por otro local con la producción de factores neurotróficos modulada por LH

Tratamento clínico da gravidez ectópica íntegra com dose única de metotrexato: quando indicá-lo? / Clinical treatment of integral ectopic pregnancy with single dose of methotrexate: when to indicate?

O objetivo do estudo foi avaliar a eficácia de um índice orientador do tratamento sistêmico da gravidez ectópica íntegra com dose única de metotrexato com o intuito de melhor selecionar os casos para o tratamento medicamentoso. Foi realizado estudo longitudinal em 40 pacientes. Os critério de inclusão foram: estabilidade hemodinâmica; massa anexial /= 5 evoluíram com sucesso (29/30-97 por cento), ao passo que notas inferiores a cinco estiveram todas relacionadas com o fracasso. O índice orientador ajuda-nos a indicar os melhores casos para o tratamento medicamentoso. Não o aconselhamos, portanto, quando a nota for inferior a cinco; por outro lado, podemos predizer boa evolução do tratamento, quando a nota for superior ou igual a cinco.

Synchronization of ovulation in crossbred dairy heifers using gonadotrophin-releasing hormone agonist, prostaglandin F2alpha and human chorionic gonadotrophin or estradiol benzoate

Girolando (Gir x Holstein) is a very common dairy breed in Brazil because it combines the rusticity of Gir (Bos indicus) with the high milk yield of Holstein (Bos taurus). The ovarian follicular dynamics and hormonal treatments for synchronization of ovulation and timed artificial insemination were studied in Girolando heifers. The injection of a gonadotrophin-releasing hormone (GnRH) agonist was followed 6 or 7 days (d) later by prostaglandin F2 alpha (PGF2alpha). Twenty-four hours after PGF2alpha injection either human chorionic gonadotropin (hCG, GPh-d6 and GPh-d7 groups) or estradiol benzoate (EB, GPE-d6 and GPE-d7 groups) was administered to synchronize ovulation and consequently allow timed artificial insemination (AI) 24 and 30 h after hCG and EB injection, respectively. Follicular dynamics in Girolando heifers was characterized by the predominance of three follicular waves (71.4 percent) with sizes of dominant follicles (10-13 mm) and corpus luteum (approximately 20 mm) similar to those for Bos indicus cattle. In the GnRH-PGF-hCG protocol, hCG administration induced earlier ovulation (67.4 h, P<0.01) compared to the control group (GnRH-PGF) and a better synchronization of ovulation, since most of it occurred within a period of 12 to 17 h. Pregnancy rate after timed AI was 42.8 (3/7, GPh-d6) to 50 percent (7/14, GPh-d7). In contrast, estradiol benzoate (GnRH-PGF-EB protocol) synchronized ovulation of only 5 of 11 heifers from the GPE-d7 group and of none (0/7) from the GPE-d6 group, which led to low pregnancy rates after timed AI (27.3 and 0 percent, respectively). However, since a small number of Girolando heifers was used to determine pregnancy rates in the present study, pregnancy rates should be confirmed with a larger number of animals

Intactness of zona pellucida does not affect the secretion of a trypsin-like protease from mouse blastocyst

Assisted hatching (AH), which is known to improve the hatching potential of mammalian embryos, has been used to increase the pregnancy rate in in vitro fertilization cycles. However, the effect of AH on a trypsin-like protease, which is known to be associated with the hatching process, has not been studied. In this study, we evaluate whether the intactness of zona pellucida affects the secretion of a trypsin-like protease from mouse blastocyst. Four- to 8-cell stage mouse embryos were collected at 66- to 68 hr after hCG injection and divided into 3 groups according to the manipulation of zona pellucida. The groups are no treatment (control), drilling of zona pellucida (ZD) and thinning of zona pellucida (ZT). The activity of a trypsin-like protease, blastocyst development and hatching rate were compared among the three groups at 110 and 135 hr after hCG injection, respectively. The protease activity and blastocyst development were not significantly different among control, ZD and ZT groups at 110 and 135 hr after hCG injection, respectively. However, the hatching rate of ZD and ZT groups was significantly higher than that of control group at each time, respectively (p>0.001). Even in the zona pellucida removed embryos, the protease activity did not differ from the control group. In conclusion, the secretion of a trypsin-like protease from mouse blastocyst does not seem to be affected by the intactness of zona pellucida.

Effect of the dopamine antagonist, domperidone alone and in combination with thyroxine, clomiphene, hcg or gnRH on serum sex steroid profile, gonadal maturation and spawning of nile catfish, clarias lazera

The present investigation was carried out on one hundred and twenty mature Clarias lazera fish during the prespawning season [March - April]. Fish were allocated into two main groups [sixty fish of each sex] Fish weight ranged between 200-220 g. b. wt. Each main group was subdivided into six equal groups [Ten fish each], Fish of each group; both males and females were subjected to the same regimen of intraperitoneal exogenous treatment, as follows. 1[st] Group: Saline 0.65% NaCL solution. [Control] 2[nd] Group: Domperidone 5 microg/g. b. wt. in saline. 3[rd] Group: Domperidone 5 microg/g. b. wt, plus thyroxine 1 nancg / g. b. wt. in saline. 4[th] Group; Domperidone 5 microg/g, b. wt. plus clomiphene citrate l gamma g/g. b wt. in saline. 5[th] Group: Domperidone 5 micro g/g. b. wt. plus hCG 2 lU/g, b. wt. in saline. 6[th] Group: Domperidone 5 microg/g. b. wt. plus GnRH 10 microg/kg. b. wt. in saline. The present study revealed that [Domperidone] administration alone, in each sex of Clarias fish; increased serum sex steroid hormones [testosterone and 17 beta estradiol], gonadal weights [testes and ovaries], final gonadal maturation and gonadosomatic indices of both sexes as compared to respective controls. Exogenous administration of domperidone plus gonadotropin releasing hormone [GnRH] was the most effective treatment for production of sex hormones, final gonadal maturation and spawning in both sexes of Clarias lazera fish, followed by domperidone plus thyroxine; domperidone plus clomiphene citrate and domperidone plus hCG, respectively. In conclusion, the exogenous administration of dopamine antagonist plus GnRH is the most efficient regimen for enhancement of gonads maturation [gonadal recrudescence], spawning and spermiation of Clarias lazera fish throughout the prespawning season

Propranolol stimulates testicular interstitial fluid formation and testosterone secretion in rats

We investigated the effect of intratesticularly injected propranolol on testicular interstitial fluid (TIF) formation and on testosterone levels in the TIF of intact adult male Wistar rats (4-9 rats per group). D1-propranolol at doses of 0.6, 1.2 or 6.0 mg/kg was injected into the left (L) testis whereas the right (R) testis (control testis) received vehicle. d1-propranolol (6.0 mg/kg) caused a significant increase in both TIF volume (329 per cent) and TIF levels of testosterone (257 per cent) in the L testis but not in the R (control) testis 3 h post-injection. In rats treated simultaneously with human chorionic gonadotropin (hCG, 5 IU/rat, sc) the same dose of propranolol (6.0 mg/kg) significantly increased the stimulatory effect of hCG on testosterone secretion by 1.8-fold, but hCG did not modify the stimulatory effect of propranolol on TIF volume. These results demonstrate a direct stimulatory effect of propranolol on TIF volume and testosterone secretion, both under basal and hCG-stimulated conditions.

Presence and release of immunoreactive atrial natriuretic peptide (ANP) in Bufo arenarum spermatozoa after HCG treatment

Atrial natriuretic peptide (ANP)-like immunoreactivity has been demonstrated in mature spermatozoa of Bufo arenarum. However, after spermiation induced by Gonadotropin Releasing Hormone (GnRH), no ANP immunoreactivity was detected in testicular spermatozoa. Recently, the presence of GnRH and GnRH receptors in amphibian testes has been demonstrated. To clarify if the loss of ANP-like immunoreactivity in spermatozoa is a direct effect of GnRH or pituitary gonadotropins, a study on Bufo arenarum adult males, has been performed. The in vivo treatment with Human Chorionic Gonadotropin (HCG) induced spermiation and loss of ANP-like immunoreactivity. The in vitro treatment with HCG showed the same results. However, in vitro GnRH treatment failed to cause spermiation and loss of ANP-like immunoreactivity. The present results indicate that ANP from mature spermatozoa is regulated via gonadotropic hormones and may be involved in the spermiation process.

Estudo prospectivo e randomizado comparando gonadotrofina coriônica humana e progesterona intramuscular para suporte da fase lútea em reproduçäo assistida / Prospective and randomized trial comparing human chorionic gonadotropin and intramuscular progesterone for lutual phase support in assisted fertilization

Os autores fazem uma análise prospectiva de 77 casos de fertilizaçao assistida (GIFT, ZIFT e IVF) distribuídos de forma randomizada para suporte da fase lútea com HCG (2000 UI nos dias 3, 6, 9 e 12 após a aspiraçao folicular) ou progesterona natural (5Omg, injeçao diária durante 14 dias). Nessa análise observaram taxas de gravidez, de implantaçao, de abortamento, níveis hormonais e complicaçoes com ênfase à hiperestimulaçao ovariana. A comparaçao entre os dois grupos nao mostrou diferença com relaçao às taxas de gravidez, implantaçao e abortamento. A incidência de prenhez ectópica e múltipla também nao foi diferente. No entanto, os níveis de estrogênio e progesterona nos dias 8 e 12, após a aspiraçao folicular, foi estatisticamente superior no grupo do HCG. Observamos uma incidência aumentada de hiperestimulaçao ovariana no grupo do HCG, demonstrando que o uso dessa medicaçao para suporte da fase lútea deve obedecer a critérios rigorosos a serem ainda melhor definidos.

Calcium-activated potassium channels ar involved in the response of mouse Leydig cells to human chorionic gonadotropin

The patch-clamp technique was used to investigate the involvement of ion channels in the response of Leydig cells to gonadotropic hormones (viz.hCG). Recordings in the cell-attached configuration (pipette containing 140 mM KCl) showed unitary events with conductance of 187.9 + or - 5.2 pS(N = 24 patches) in about 70 percent of the cells. These channels were potassium selective and the open channel probability (Po) was always about 1 percent for displacemtne of potential from the resting value in the range of -20 to +60 mV. Treatment of the cells with hCG (2 ng/ml) led to a large increase in the frequency of openings, concomitant with a reduction in the mean closed time and there was essentially no effect on the mean open time of the channels. Dibutyryl cAMP (100 µM) produced an effect similar to that of hCG and both required external calcium for their action. No direct effect of either dibutyryl cAMP or hCG were observed in inside-out patches. Reversal potential measurements on excised inside-out patches demonstrated that the channels were highly potassium selective with unitary conductance of about 206.8 + or - 6.36 pS(mean + or - SEM of 6 measurements), and an estimated permeability of 3.6 x 10-13 + or - 0.2 x 10--13 cm3/s (mean + or - SEM for 6 measurements), in symmetrical 140 mM KCl. The activity of the channel in excised paches was very sensitive to the free-calcium concentration on the intracellular surface of the free-calcium concentration on the intracellular surface of the channel. Po evaluated at + 60mV increased from 3 percent at 10 nM to 47 percent at 100 nM free calcium. The Hill coefficient under these conditions was 1.1. These results demonstrate that Leydig cells have a Ca2+ -activated K+ channel of large unitary conductance, which can be activated upon the binding of hCG to receptors in the cell membrane

Estudo comparativo entre a ultra-sonografia transvaginal e transabdominal na avaliaçäo do endométrio de mulheres com ciclos menstruais espontâneos e induzidos / A comparative study between transvaginal and transabdominal ultrasound in the evaluation of the endometrium of women with spontaneous and induced menstrual cycles

Estudamos a espessura e a textura do endométrio comparando-se US transabdominal com US transvaginal. Avaliamos 45 pacientes do ambulatório de Ginecologia e Infertilidade do Hospital de Clínicas de Porto Alegre, entre abril de 1990 e junho de 1992. As 45 pacientes foram divididas em três grupos: grupo A, com ciclos menstruais espontâneos; grupo B.1, com ciclos induzidos pelo citrato de clomifeno; grupo B.2, com ciclos induzidos pelo citrato de clomifeno/gonadotropina humana da menopausa/gonadotropina coriônica humana. No grupo A foram estudados o oitavo, décimo, 12( e 21( dias do ciclo menstrual. Nos grupos B.1 e B.2 estudaram-se os mesmos dias, excluindo-se o 21(. Nos grupos A e B.1, a espessura endometrial medida pela US transvaginal foi significantemente maior quando comparada com a transabdominal, excetuando-se o primeiro dia do exame, quando os resultados sugerem igualdade. No grupo B.2, nao houve diferença significante de resultados, excetuando-se o primeiro dia do exame, quando os resultados sugerem igualdade. A textura do endométrio foi absolutamente coincidente quando se comparou a via transabdominal com a transvaginal.

Evaluación morfologia de las uniones intercellulares en el ovario del embrión de pollo: acción de hormonas esteroideas y gonadotroficas in vitro / Morphological evaluation of intercellular junctions in the ovary of chick embryos: action of steroid and gonadotropic hormones in vitro

Se determinaron las variaciones de las uniones intercelulares de las células germinales y epiteliales en el epitelio ovárico producidas por hormonas gonadotróficas y esteroideas sobrelos ovarios del embrión de pollo a los 7 días de desarollo. Se cultivaron explantos de ovarios derecho e izquierdo Sin (controles) y con adición de hormonas (experimental durante 4 días. Los cultivos fueron procesados para su estudio ultraestructural (MET). En ambos ovarios controles los complejos de unión eran similares a los identificados in ovo. En el ovario izquierdo se observó aumento y mayor desarollo de las uniones adherens y desmosomas; en el ovario derecho los mismos disminuyeron por acción de 17 Beta-estradiol. La respuesta del ovario izquierdo a la progesterona y testoterona fue similar a la obtida con estrógeno. En la gónada derecha no se observaron cambios. En ambos ovarios se produjo una dismunucíon de las uniones intercelulares por accíon de FSH. Los cambios producidos por LH y hCG fueron semejantes a los encontrados en el ovario izquierdo por efecto del estrógeno, consistentes en un incremento de los complejos de uníon, principalmente los de tipo adherens. Estos análisis indican que las hormonas esteroideas y gonadotróficas actúan modificando las uniones intercelulares y participarían en los procesos de crecimiento y atrofia que ocurren en los ovarios del embríon de pollo.

Induction of spermatogenesis by exogenous gonadotrophins during nonbreeding season in Calotes versicolor.

Treatment of exogenous gonadotrophins(PMSG, hCG and PMSG+hCG) to male C. versicolor during nonbreeding phase resulted in increased weight of testis and its diameter. The seminiferous tubular diameter was also increased and tubules were filled with spermatogenic elements like spermatogonia, primary and secondary spermatocytes and spermatids. The results suggest that mammalian nonpituitary gonadotrophins(PMSG and hCG) also posses the potency to stimulate spermatogenesis in reptilian testis. Lowered cholesterol levels of testis, increased weight and protein content of epididymis after gonadotrophins treatment indicate that the exogenous gonadotrophins could initiate the steroidogenesis in testis. Interstitial space was enlarged and filled with active Leydig cells. Spermatogenesis was not complete as no spermatozoa were observed in the lumen of seminiferous tubule. The factors essential for the completion of spermatogenesis are discussed.