Follicle-stimulating Hormone Stimulation Research Articles

Gonadotropin stimulation of the expansion of cumulus oophori isolated from mice: General condition for expansion in vitro

AbstractGonadotropin Stimulation of the Expansion of Cumulus Oophori Isolated from Mice: General Conditions for Expansion In VitroThe hormonal stimulation of cumulus expansion (mucification) was studied using oocyte‐cumulus cell complexes isolated from Graafian follicles of C57BL/6J mice. Cumulus expansion was stimulated in vitro with human chorionic gonadotropin (HCG) and highly purified rat follicle stimulating hormone (FSH) in Whitten's medium containing fetal bovine serum (FBS). Highly purified rat luteinizing hormone failed to stimulate cumulus expansion. The 50% maximal stimulating concentration of FSH was found to be about 3–4 ng/ ml. Cumulus expansion was also stimulated by dibutyryl cyclic adenosine monophosphate (DBcAMP), but not by dibutyryl cyclic guanosine monophosphate or butyrate. Neither progesterone, testosterone, nor 17β‐estradiol stimulated cumulus expansion. Expanded cumuli were dispersed by hyaluronidase.The stimulation of cumulus expansion by FSH, HCG or DBcAMP required the presence of FBS. The active component of serum had a molecular weight greater than 10,000 daltons and did not require the association of a steroid for activity. Since DBcAMP does not stimulate cumulus expansion in the absence of FBS, it is suggested that the serum factor(s) is involved after the step of FSH stimulation of cAMP production by the complex.The cumulus does not expand if FSH is added to cultures after seven hours of spontaneous oocyte maturation, when the oocytes are at late metaphase I or early anaphase I of meiosis. Therefore, the changes which occur in the oocytecumulus cell complex during spontaneous oocyte maturation affect the ability of the complex to respond to FSH and bring about the expansion of the cumulus.

Hormonally induced cell shape changes in cultured rat ovarian granulosa cells.

Cultured rat ovarian granulosa cells undergo a dramatic morphological change when exposed to follicle-stimulating hormone (FSH). Exposure to FSH causes the flattened epithelioid granulosa cells to assume a nearly spherical shape while retaining cytoplasmic processes which contact the substrate as well as adjacent cells. This effect of FSH is preceded by a dose-dependent increase in intracellular cAMP, is potentiated by cyclic nucleotide phosphodiesterase inhibitors, and is mimicked by dibutyryl cAMP. Prostaglandins E1 or E2 and cholera enterotoxin also cause the cells to change shape. A subpopulation of the cells responds to luteinizing hormone. These morphological changes, which are blocked by 2,4-dinitrophenol, resemble those produced by treating cultures with cytochalasin B. Electron microscopy shows that the unstimulated, flattened cells contain bundles of microfilaments particularly in the cortical and basal regions. After FSH stimulation, microfilament bundles are not found in the rounded granulosa cell bodies but they are present in the thin cytoplasmic processes. These data suggest that the morphological change results from a cAMP-mediated, energy-dependent mechanism that may involve the alteration of microfilaments in these cells.

Hormone interactions in the sertoli cells

The effects of follicle-stimulating hormone (FSH) and testosterone in rat Sertoli cells were investigated in vitro by means of isolated cell populations. The Sertoli cells selectively bind FSH, and respond to FSH stimulation with increased accumulation of endogenous cyclic AMP and secretion of androgen-binding protein (ABP). FSH binding and cyclic AMP response in the Sertoli cells change dramatically during sexual maturation. Cyclic AMP response decreases despite an increase in FSH-binding receptors per cell. Evidence has been provided for the existence of cytoplasmic and nuclear androgen receptors and chromatin acceptor-sites that specifically bind the androgen-receptor complex in the Sertoli cells. A model has been proposed for the hormonal interactions in the seminiferous tubule and the possible role of Sertoli cells in mediating the hormonal effects on spermatogenesis.

Stimulation of Luteinizing Hormone (LH) and Follicle-Stimulating Hormone by [D-Leu6,Des-Gly10-NH2]-LH-Releasing Hormone Ethylamide after Subcutaneous, Intravaginal, and Intrarectal Administration to Women

Women, most of whom had regular menstrual cycles, were administered D-Leu6,des-Gly10-NH2)-luteinizing hormone-releasing hormone (LH-RH) ethylamide (D-Leu6-LH-RH-EA)via different routes during the early or midfollicular phase of the cycle. Plasma LH, follicle-stimulating hormone (FSH), and estrogen levels were determined by radioimmunoassay before and after administration of D-Leu6-LH-RH-EA. plasma LH and FSH increased and reached peak levels 3 to 4 hours and 3 to 6 hours, respectively, after subcutaneous injection of 25 mug of the analog of LH-RH. Intravaginal or intrarectal application of 2 mg of D-Leu6-LH-RH-EA also increased plasma LH and FSH levels in most of the women, but the magnitude of the rise, the time of initiation of response, and the peak level varied among the women. The plasma estrogen level also rose after administration via either route.

FSH stimulation of DNA synthesis in sertoli cells in culture

The incorporation of [ 3H] thymidine into nuclear DNA was investigated in cultured Sertoli cells prepared from testes of 20-day-old rats. Addition of follicle-stimulating hormone (FSH) or dibutyryl cyclic, 3',5'-adenosine monophosphate (dbcAMP) to the culture medium greatly increased incorporation, expressed either as total amounts of [ 3H] thymidine incorporated per μg DNA or as the percentage of Sertoli cells with labeled nuclear DNA. No stimulation was observed in cells cultured in the presence of testosterone, insulin or cyclic 3',5'-GMP (cGMP). Light and electron microscopic autoradiographic analysis was employed to establish the identity of Sertoli cells having labeled nuclear DNA. Contaminating spermatogonia, which also took up labeled [ 3H] thymidine, were excluded from cell counts. In addition, Sertoli cells prepared from testes of irradiated 20-day-old germinal cell depleted rats were also observed to incorporate more [ 3H] thymidine into nuclear DNA when cultured in a chemically defined medium in the presence of FSH. DNA synthesis was abolished by prior treatment of cells with cytosine arabinoside. In separate experiments, the incorporation of [ 3H] thymidine into DNA of peritubular myoid cells was shown to be independent of FSH or dbcAMP.

Isolation and Culture of FSH Responsive Sertoli Cells

Methods for the isolation and culture of enriched populations of Sertoli cells from 20-60 day old rats are described. The identity of the Sertoli cells was verified by bright light and electron microscopy. Freshly isolated Sertoli cells specifically bound follicle stimulating hormone (FSH) but not luteinizing hormone (LH) and responded to FSH stimulation with dramatic increase in cyclic AMP level. Isolated Sertoli cells, maintained in culture for 11 days, showed no evidence of proliferation but retained their characteristic ultrastructural features and FSH binding ability. Incubation of cultured cells with FSH resulted in a significant stimulation of cyclic AMP and androgen binding protein (ABP). Since the freshly isolated or cultured cells were predominantly (greater than 80%) Sertoli cells, these results provide direct evidence that the Sertoli cells represent a primary target site for FSH activity in the testes. The culture method also provides a valuable in vitro model for the study of chronic effects of various agents on the Sertoli cell.

PITUITARY-GONADAL RELATIONS IN FEMALE CHILDREN AND ADOLESCENTS

Extract: Data are provided which concern daytime levels of circulating follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol and progesterone in healthy female children and adolescents. These findings are correlated with sexual and skeletal maturation. Serum estradiol and testosterone levels were low in childhood, but rose to adult levels coincident with the appearance of secondary sexual characteristics. Serum LH levels did not rise above prepubertal levels until these characteristics were already apparent. Serum FSH levels showed a biphasic pattern with age; widely scattered values, some into the adult range, were seen in infancy. Mean FSH levels then declined throughout childhood until the onset of clinical puberty at which time they increased again to adult levels. Serum progesterone concentrations remained low (below 150 ng/100 ml) until menarche. Levels of serum progresterone which suggested possible ovulation and corpus luteum formation (over 200 ng/100 ml) were found in 9 of 30 girls who were less than 3 years postmenarchal. Speculation: The finding of high serum FSH levels in female, but not in male, infants suggests that the infantile ovary may be relatively resistant to FSH stimulation. The decline in FSH levels during early childhood may represent increasing ovarian maturation, at least in terms of ability to secrete as yet unidentified gonadotropin-inhibiting feedback substance (or substances). The onset of female puberty appears to be heralded by increasing FSH secretion; although nocturnal LH release may be characteristic of early puberty, daytime elevation of this hormone is not seen until midpuberty. The surprising finding of luteal range serum progesterone levels in many early postmenarchal girls suggests that anovulatory cycles may not be characteristic of these years. The reported relative infertility of adolescent girls may relate to factors other than ovulation (such as a short corpus luteum life-span, defects in sperm capacitation, or impaired blastocyst implantation).

Effects of mammalian and host gonadotropins on the ovaries and oviducts of female texas horned lizards, Phrynosoma cornutum

1. 1. The effects of bovine luteinizing hormone (LH), ovine follicle-stimulating hormone (FSH), ovine prolactin, Phrynosoma pituitary extract and pituitary extract that had been treated with neuraminidase were studied on the reproductive system of female horned lizards. Animals were hypophysectomized, and hormone treatments were begun on the sixth day following surgery. 2. 2. In hypophysectomized control animals no significant changes in ovarian weights were noted from the intact controls; however, there was a significant decrease in the oviduct weights and the width of the oviduct wall. 3. 3. Treatment with mammalian LH (1 mg) and FSH (1 mg) produced significant increases in follicle wall diameters. In all cases the stimulation of FSH was greater than that of LH. Concurrent treatment with FSH and LH did not produce synergistic effects. 4. 4. Animals treated with prolactin (2·5 mg) exhibited no increase in ovarian weight but did show increases in oviduct weight, width of oviduct wall and width of follicle walls. Prolactin treatment also induced profuse ecdysis. 5. 5. Treatment with host pituitary extract (2·5 mg) produced significant increases in all parameters. On the other hand, neuraminidase treatment appeared to destroy completely the biological activity of the preparation. This suggests that the Phrynosoma gonadotropin molecule is “FSH-like”.

Pituitary-gonadal relations in female children and adolescents.

Extract: Data are provided which concern daytime levels of circulating follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol and progesterone in healthy female children and adolescents. These findings are correlated with sexual and skeletal maturation. Serum estradiol and testosterone levels were low in childhood, but rose to adult levels coincident with the appearance of secondary sexual characteristics. Serum LH levels did not rise above prepubertal levels until these characteristics were already apparent. Serum FSH levels showed a biphasic pattern with age; widely scattered values, some into the adult range, were seen in infancy. Mean FSH levels then declined throughout childhood until the onset of clinical puberty at which time they increased again to adult levels. Serum progesterone concentrations remained low (below 150 ng/100 ml) until menarche. Levels of serum progresterone which suggested possible ovulation and corpus luteum formation (over 200 ng/100 ml) were found in 9 of 30 girls who were less than 3 years postmenarchal.Speculation: The finding of high serum FSH levels in female, but not in male, infants suggests that the infantile ovary may be relatively resistant to FSH stimulation. The decline in FSH levels during early childhood may represent increasing ovarian maturation, at least in terms of ability to secrete as yet unidentified gonadotropin-inhibiting feedback substance (or substances). The onset of female puberty appears to be heralded by increasing FSH secretion; although nocturnal LH release may be characteristic of early puberty, daytime elevation of this hormone is not seen until midpuberty. The surprising finding of luteal range serum progesterone levels in many early postmenarchal girls suggests that anovulatory cycles may not be characteristic of these years. The reported relative infertility of adolescent girls may relate to factors other than ovulation (such as a short corpus luteum life-span, defects in sperm capacitation, or impaired blastocyst implantation).

Response of immature gonads of Ceratophrys ornata to FSH

Follicle-stimulating hormone (FSH) injected into recently metamorphosed toad Ceratophrys ornata, a differentiated race which differentiates its gonads shortly before metamorphosis, brings about in the male gonad the transformation of the solid testicular cords into a spongelike network of testicular ampullae containing only one type of germinal cell, the spermatogonia, surrounded by typical follicular cells. In the female gonad, there is no ampullae formation, but a remarkable increase in germinal cell population. This different response shows that the female gonad is more sensitive to the proliferative stimulation of FSH than the male gonad. In recently metamorphosed toads of the species Ceratophrys ornata, in contrast to another differentiated race, Pleurodema cinerea, which differentiates its gonads long before metamorphosis, FSH treatment fails to produce a complete spermatogenesis. We conclude that the time of differentiation of the male gonad is the important factor in the response to FSH, not the sex race.

Some Observations on the Assay of Anterior Pituitary Hormones

Publisher Summary This chapter describes some observation on assay methods for anterior pituitary hormones that may be divided into two main groups–biological and immunological. Biological methods have been employed for many years, whereas immunological methods were introduced relatively recently. Immunological assays are often more practicable than bioassays and for this reason are gradually replacing the latter in clinical studies. At present, biological or immunological, but not chemical, assay methods must be employed for the quantitative determination of follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin, growth hormone, adrenocorticotropic hormone (ACTH), and thyroid stimulating hormone (TSH) in standard preparations and biological fluids. The chapter discusses both biological and immunological assays for these hormones. Only in the case of ACTH has the hormone been synthesized, but the extracts of sufficient purity to produce potent antisera are available for human growth hormone, ACTH, and TSH. As yet such materials are not readily available for human LH and FSH; and for this reason, progress in the development of immunological assays for these substances have been slow.