Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.6.1.1 (adenylate cyclase)
 19,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The objective of this study was to characterize the corpora lutea (CL) of superovulatory follicles, which form in nonhuman primates after treatment with exogenous gonadotropins. Adult female rhesus monkeys (n = 15) with amenorrhea or irregular menstrual cycles received im injections of either human menopausal gonadotropin [hMG; equivalent amounts (37.5 IU) of hFSH and hLH] or human FSH (37.5 IU) twice daily for 6 or 9 days. One day later, hCG (1000 IU) was administered to induce ovulation. Serum estradiol levels rose rapidly in hMG-treated monkeys. In contrast, estradiol levels did not rise in FSH-treated animals for 3-4 days, but ultimately reached concentrations comparable to or greater than those in hMG-treated monkeys. Serum progesterone levels were low in all groups before hCG injection, but rose thereafter. Peak progesterone levels were greater (P less than 0.05) in 9- vs. 6-day treatment groups. Serum concentrations of hCG peaked within 24 h of injection and declined to undetectable levels 6-7 days later. The mass of luteinized tissue removed 7 days after hCG injection was markedly (P less than 0.01) increased in hMG- and FSH-treated monkeys compared to that of the active CL of the natural menstrual cycle (n = 6). However, the protein content of luteal tissue from FSH-treated monkeys was less (P less than 0.05) than that in hMG-treated groups or in the CL of the natural cycle. Luteal particulate fractions from all treatment groups had [125I]human LH binding sites, with the Kd for LH interaction comparable to that in the CL of the natural cycle. However, the LH-binding capacity in hMG-treated groups was less (P less than 0.05) than that in the CL of the cycle, when normalized per mg tissue wt or protein. Notably, the binding capacity in FSH-treated groups was comparable to that in the CL cycle when expressed per mg protein. Nevertheless, only after 6 days (not 9 days) of FSH treatment or 9 days (not 6 days) of hMG treatment did tissues have a LH-sensitive (activation constant) or LH-responsive adenylate cyclase comparable to that in the CL of the cycle. Thus, properties of the primate CL after superovulation varied markedly with the type and length of gonadotropin treatment employed for follicular stimulation. The findings support the concept that gonadotropin-regulated events in the developing follicle(s) are important determinants of the subsequent character of the primate CL.
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PMID:Characterization of corpora lutea in monkeys after superovulation with human menopausal gonadotropin or follicle-stimulating hormone. 300 56

The basic foundation for normal puberty and adult reproductive function is established during fetal life with the adequate development of the hypothalamus, pituitary and gonads. Further maturation and differentiation of the hypothalamic-pituitary-gonadal axis continues throughout childhood, puberty, adult life and senescence. Pituitary FSH and LH play a central role in the cascade of events in the hypothalamic-pituitary-gonadal axis by mediating between the brain and hypothalamus on one hand and the end-organ, the ovary, on the other. Absent or low pituitary secretion of FSH and LH, as occurs in hypothalamic/pituitary hypogonadism, leads in women to anovulation, amenorrhoea and absent ovarian follicular development. The ability of gonadotrophins to modulate ovarian function depends on their rate of synthesis by the pituitary gonadotrophs, on their circulating concentrations (which vary throughout life and throughout the menstrual cycle), on the relative abundance of the multiple forms of gonadotrophins that have varying biological activity, on the presence of their receptors on the different cell types of the ovary, on the intracellular adenylate cyclase enzyme that causes the production of cAMP, and on the extra- and intragonadal factors that are able to modulate the effects of gonadotrophins in the ovary. Recent clinical and basic research with recombinant gonadotrophins, molecular biological studies on the localization, function and regulation of the long sought after gonadotrophin receptors, as well as research on the interaction between gonadotrophins and local intragonadal factors have widened our knowledge about the function and role of FSH and LH in the ovary and have provided new insights into previously unanswered questions of ovarian physiology and pathophysiology and will provide the basis for the design of new treatment strategies to overcome ovulatory gonadotrophin-dependent dysfunction in the future.
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PMID:The differential effects of FSH and LH on the human ovary. 835 90