Effects of Luteinizing Hormone on Progestin Biosynthesis in the Luteinized Rat Ovary

Acute Effects of Various Gonadotropins and Other Pituitary Hormones on Preovulatory Ovarian Progestin Secretion in Hypophysectomized Rats

“…This coincides with the time of LH release from the pituitary which has been determined by Kobayashi et al (1968) using the same laboratory rats bred under the same conditions. This fact suggests that the increase of progesterone at proestrus is caused by LH, since there are evidences that LH causes an increase in rat ovarian progesterone synthesis in vivo (Marsh et al, 1966;Yoshinaga et al, 1967) and in vitro (Armstrong and Greep, 1962;Armstrong et al, 1964;Channing and Villee, 1966;Major et al, 1967;Chatterton et al, 1968). In this connection, the decrease of progesterone concentration in the ovarian tissues after the surge of gonadotropins on the evening of the day of proestrus was far too small to account for the observed increase of secretion (unpublished data).…”

Studies on the Mechanism of Nidation

“…Therefore (Shelesnyak, 1962 (Rothchild, 1962;Schwarz & Rothchild, 1964). Furthermore, Eto, Masuda, Shzuki & Hosi (1962) and Armstrong, O'Brien & Greep (1964) have demonstrated that administration of lh caused immediate release of progesterone from luteinized rat ovaries both in vivo and in vitro. Finally it has been shown that ovulation occurs around L12 in some pseudopregnant rats which are bearing deciduomata (Lobel et al, 1965).…”

Effect of Ovariectomy and of Various Hormones on the Synthesis of Progesterone by the Guinea-Pig Placenta in Vitro

“…The final dry residue from the solvent extraction procedure was subjected to two dimensional thin layer chromatography (Armstrong, O'Brien & Greep, 1964). Progesterone was located on chromatograms by observation under ultra-violet light (254 nm) and the appropriate areas of silica gel eluted with 2-5 ml of methanol.…”