New data on luteotropic mechanism of action of estrogens during the rat estrus cycle
Roos, J.; Plas-Roser, S.; Hassani, M.; Aron, C.
Comptes Rendus des Seances de la Societe de Biologie et de ses Filiales 171(2): 446-450
1977
ISSN/ISBN: 0037-9026 PMID: 142568 Document Number: 122736
An increase in peripheral blood progesterone concentration was observed in diestrus II, at 17:30 in 4-day cyclic female rats subcutaneously injected with 10 microgram estradiol benzoate (EB) at 10:00-11:00 on diestrus I. Pentobarbital injection (30 mg/kg) at 13:30 on diestrus II did not prevent this effect on EB. By contrast PB injected at 13:30 on diestrus II as above completely suppressed the luteinizing or ovulating effects of EB. The action of estrogen on blood progesterone level was therefore concluded to be unrelated to the mechanisms underlying estrogen-induced ovulation luteinization in the cyclic female rat.