Cooperative inhibitory effect of follicular fluid and cAMP on hamster oocyte maturation

Gonadotropin-releasing hormone in Cyprinidae as in other Vertebrates functions as a brain signal which stimulates the secretion of luteinizing hormone from the pituitary gland. Two forms of gonadotropin-releasing hormone have been identified in cyprinids, chicken gonadotropin-releasing hormone II and salmon gonadotropin-releasing hormone. Hypohysiotropic functions are fulfilled mainly by salmon gonadotropin-releasing hormone. The only known factor having an inhibitory effect on LH secretion in the family Cyprinidae is dopamine. Most cyprinids reared under controlled conditions exhibit signs of reproductive dysfunction, which is manifested in the failure to undergo final oocyte maturation and ovulation. In captivity a disruption of endogenous gonadotropin-releasing hormone stimulation occurs and sequentially that of luteinizing hormone, which is indispensible for the final phases of gametogenesis. In addition to methods based on the application of exogenous gonadotropins, the usage of a method functioning on the basis of hypothalamic control of final oocyte maturation and ovulation has become popular recently. The replacement of natural gonadotropin-releasing hormones with chemically synthesized gonadotropin-releasing hormone analogues characterized by amino acid substitutions at positions sensitive to enzymatic degradation has resulted in a centuple increase in the effectiveness of luteinizing hormone secretion induction. Combining gonadotropin-releasing hormone analogues with Dopamine inhibitory factors have made it possible to develop an extremely effective agent, which is necessary for the successful artificial reproduction of cyprinids.

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ALTERED FOLLICULAR FLUID MICRO RNA PROFILES IN POLYCYSTIC OVARIAN SYNDROME MAY SERVE AS PREDICTIVE BIOMARKERS OF OOCYTE MATURATION STAGE

Fertility and Sterility ◽

10.1016/j.fertnstert.2020.09.068 ◽

2020 ◽

Vol 114 (3) ◽

pp. e543-e544

Author(s):

Tamar Matitashvili ◽

Sezgi Arpag ◽

Seifeldin Sadek ◽

Gerard Celia ◽

Laurel Stadtmauer ◽

...

Keyword(s):

Oocyte Maturation ◽

Follicular Fluid ◽

Polycystic Ovarian Syndrome ◽

Predictive Biomarkers ◽

Micro Rna ◽

Maturation Stage ◽

Ovarian Syndrome

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Adenosine 3″,5″-Monophosphate Levels in Human Follicular Fluid: Relationship to Oocyte Maturation and Achievement of Pregnancy afterin VitroFertilization

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jcem-60-6-1111 ◽

1985 ◽

Vol 60 (6) ◽

pp. 1111-1115 ◽

Cited By ~ 8

Author(s):

B. C. TARLATZIS ◽

N. LAUFER ◽

A. H. DECHERNEY ◽

M. L. POLAN ◽

F. P HASELTINE ◽

...

Keyword(s):

Oocyte Maturation ◽

Follicular Fluid ◽

Human Follicular Fluid

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Aromatase activity in the mare ovary during estrous cycle. Measurement of endogenous steroids and of their in vitro inhibitory effect

Acta Endocrinologica ◽

10.1530/acta.0.1290536 ◽

1993 ◽

Vol 129 (6) ◽

pp. 536-542 ◽

Cited By ~ 9

Author(s):

Hakima Amri ◽

Pierre Silberzahn ◽

Ihsan Al-Timimi ◽

Jean-Luc Gaillard

Keyword(s):

Follicular Fluid ◽

Luteal Phase ◽

Physiological Role ◽

Inhibitory Effect ◽

Aromatase Activity ◽

Estrogen Production ◽

Estrogen Synthesis ◽

Luteal Tissue ◽

Endogenous Steroids

This present study was undertaken to clarify estrogen synthesis in the mare ovary. First of all, an evaluation of endogenous steroid contents was carried out in the follicular fluid and in the luteal tissue at different stages of the luteal phase. Radioimmunoassays were performed after separation and purification of each hormone by chromatography. High amounts of conjugated (0.9 mg/l) and unconjugated (4 mg/l) estradiol-17β were found in the follicular fluid of the large follicules (50 mm). These concentrations of estrogens decreased drasticaly in the luteal tissue, and only low levels of circulating estrogens are found during the luteal phase. On the other hand, a high aromatization ability has been evidenced in the cyclic corpus luteum in vitro. In an attempt to clarify the regulation of estrogen synthesis, we have tested the inhibitory effect of several endogenous steroids on equine ovarian aromatase activity. 5α-Dihydrotestosterone appeared to be the most potent competitive inhibitor (Ki= 181 nmol/l) of aromatase activity, while the addition of a 3-sulfate group induced a slump in the inhibitory potency of estrone (Ki= 397 nmol/l vs 2206 nmol/l) and dehydroepiandrosterone (Ki = 291 nmol/l vs 6157 nmol/l). The physiological role of these conjugated steroids has not been known until now; we suggest that they would play a role in protecting aromatase from inhibition, in vivo. The high amounts of progesterone found in the luteal tissue (1.3 g/kg of proteins) might play a role in the regulation of estrogen production either by suppressing the induction of aromatase synthesis or by inhibiting the activity of the enzyme complex.

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In vitro development of morulae from immature caprine oocytes

Zygote ◽

10.1017/s0967199400001842 ◽

1994 ◽

Vol 2 (2) ◽

pp. 97-102 ◽

Cited By ~ 10

Author(s):

Levent Keskintepe ◽

Gamal M. Darwish ◽

Abdelmoneim I. Younis ◽

Benjamin G. Brackett

Keyword(s):

Oocyte Maturation ◽

Follicular Fluid ◽

Glycoprotein Hormones ◽

Glycoprotein Hormone ◽

In Vitro Development ◽

Morula Stage ◽

Vitro Development ◽

Hormone Control ◽

Medium Supplementation

SummaryThe effects of medium supplementation with oestrous goat serum and glycoprotein hormones on caprine oocyte maturation in vitro (IVM) were evidenced by proportions of resulting ova completing in vitro fertilisation (IVF) and development to the morula stage. Oocyte-cumulus complexes (OCCs) were harvested in follicular fluid from 2–5 mm diameter follicles. Oocyte maturation took place during 27 h in TCM-199 supplemented with 20% oestrous goat serum, oestradiol-17β (1.0 μg/ml), and either (a) 0.5 μg FSH/ml, (b) 100 μg LH/ml, (c) 100 μg LH + 0.5 μg FSH/ml, (d) 100 μg hCG + 0.5 μg FSH/ml, (e) 0.5 μg TSH/ml or (f) no added glycoprotein hormone (control). Of 353 immature oocytes cultured in seven experiments, 311 (88.1%) exhibited cumulus expansion at the end of the IVM interval; all normalappearing OCCs were inseminated. In vitro insemination was with ejaculated sperm treated with heparin (10 μg/ml) and caffeine (0.4 μg/ml). Proportions (%) of inseminated ova that were fertilised (cleaved) and that reached the morula stage after IVM with (a) FSH, (b) LH, (c) LH + FSH, (d) hCG + FSH, (e) TSH and (f) no added glycoprotein hormone were (a) 22/52 (42.3%) and 9/52 (17.3%), (b) 25/54 (46.3%) and 14/54 (25.9%), (c) 52/65 (80.0%) and 26/65 (40.0%), (d) 48/78 (61.5%) and 22/78 (28.2%), (e) 14/54 (25.9%) and 4/54 (7.4%), and (f) 11/50 (22.0%) and 1/50 (2.0%), respectively. All treatments yielded better results than IVM with no added glycoprotein hormone. After IVM with added LH + FSH higher proportions of oocytes were fertilised (p<0.05), and higher proportions reached the morula stage (p<0.05) when compared with other treatments.

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