Inhibition of progesterone secretion in cultured human granulosa cells by a low molecular weight fraction of human follicular fluid

Effects of human serum on rat cumulus-oocyte complex functions in vitro: oocyte activation and endocrine secretions

Secretion of hormones and oocyte meiotic events were assessed following in vitro culture of ovulated rat cumulus-oocyte complexes (COCs) in media containing different types of human serum. Both toxic and nontoxic (determined by mouse embryo test) samples of fetal cord or adult female serum were utilized for these experiments. After short-term culture (4.5 hr), with or without COCs, medium containing 10% serum was collected and analyzed for its content of estradiol, progesterone, and prostaglandin E (PGE), and oocytes were cytologically evaluated for spontaneous activation (second polar-body extrusion). Activation of oocytes occurred in all media tested. Steroids (progesterone and estradiol) levels were markedly elevated in culture medium containing cord serum as compared to medium containing adult female serum. The progesterone content of culture medium decreased after incubation of COCs with cord serum and increased when incubated with adult female serum. Little or no prostaglandin was detected in any control media. However, COCs secreted prostaglandin during culture in all media. COCs secreted estradiol when cultured in medium containing cord but not adult female serum. Results demonstrate that two types of serum utilized for in vitro culture of COCs varied markedly in their hormone content and differentially affected the secretion of hormones by COCs during culture. The results are discussed in relation to the success of IVF procedures.

Paracrine regulation of follicular maturation in primates

Taken together, the studies reviewed here suggest that although gonadotropins are necessary for follicular growth, they are insufficient by themselves to explain the dynamics of folliculogenesis. Indeed, the role of gonadotropins in follicular maturation must necessarily be permissive: that is LH and FSH initiate a synchronized cascade of follicular events directly mediated by paracrine and autocrine factors.

Stimulatory effects of follicle-stimulating hormone and luteinizing hormone upon secretion of progesterone and inhibin activity by cultured infant human ovarian granulosa cells

Ovarian tissue obtained from three human infants (60, 120, and 210 days of age) was separated into cell types and cultured. Granulosa cells from two of three subjects were viable and grew in culture. The cells had the potential to secrete low levels of progesterone and responded to luteinizing hormone and follicle-stimulating hormone added in culture with greatly enhanced ability to secrete progesterone. Granulosa cells could also secrete inhibin activity in culture and responded to luteinizing hormone and follicle-stimulating hormone with enhanced inhibin secretion. The granulosa cells also had the potential to secrete estrogen in the presence of testosterone. Serum levels of gonadotropin in the human infant are elevated for a period between 1 and 4 months; yet only follicular growth, not luteinization, occurs. It can be concluded that infant human granulosa cells, like adult human granulosa cells, have the potential of responding in vitro to gonadotropin.