In vitro transfer rate of 14C from acetate-1-14C into ovarian steroids in the rat ovary during the estrous cycle and effects of LH and FSH.
Fluctuations of ovarian biosynthetic activity and effects of exogenous LH and FSH on it during the estrous cycle were investigated by measuring in vitro transfer rates of 14C from 14C-1-acetate into progesterone (P), 20 alpha-hydroxy-pregn-4-en-3-one (20 alpha-OH-P) and estrogen (estradiol and estrone, E) in the ovarian homogenates from rats autopsied at 2 hour intervals. The transfer rate of 14C from 14C-1-acetate into P was lowest in the afternoon of estrus and increased from the morning of diestrus 1, making its peaks during the afternoon of diestrus 2 and in the midnight of proestrus. The transfer of 14C into 20 alpha-OH-P was high on the days of diestrus 2 and proestrus with its peak in the afternoon of the latter day. The maximum transfer of 14C into E in the afternoon of proestrus and a high rate in the morning of estrus with relatively low one in the midnight were observed. Exogenously injected LH (150 mug) or FSH (150 mug) was either stimulatory or inhiibitory to the transfer rates of 14C from 14C-1-acetate into ovarian steroids. During day time of diestrus 2 and midnight between proestrus and estrus, the transfer of 14C into P and 20 alpha-OH-P increased by LH, and during day time of proestrus and from the afternoon of estrus to the morning of diestrus 1 decreased. The transfer of 14C into E increased by LH from the afternoon of diestrus 2 to the morning of proestrus, and decreased during the afternoon of proestrus and from the afternoon of estrus to the morning of diestrus 2. Administration of FSH was also stimulatory or inhibitory. The 14C transfer into P and 20 alpha-OH-P increased by FSH from the afternoon of estrus to the morning of proestrus, but in the afternoon of proestrus they decreased. Transfer of 14C into E increased by FSH significantly on the days of diestrus 2 and proestrus, and slightly on the day of estrus, while it decreased in the afternoon of diestrus 1.
D000085:Acetates / Q000378:metabolism; D000818:Animals; D004031:Diestrus; D004967:Estrogens / Q000096:biosynthesis; D004971:Estrus; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D012739:Gonadal Steroid Hormones / Q000096:biosynthesis*; D007986:Luteinizing Hormone / Q000494:pharmacology*; D010053:Ovary / Q000378:metabolism*; D011247:Pregnancy; D011359:Proestrus; D011374:Progesterone / Q000096:biosynthesis; D051381:Rats
D000085:Acetates; D004967:Estrogens; D012739:Gonadal Steroid Hormones; D011374:Progesterone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone