Ovarian secretion of oxytocin is stimulated by prostaglandin

Differential regulation by LH and prostaglandins of steroidogenesis in small and large luteal cells of the ewe

“…Koos & Hansel (1981) also tested the effect of PGF-2a on isolated small and large luteal cells and found that it had no effect on basal or LH-stimulated progesterone secretion. In addition, although the prostaglandin analogue cloprostenol stimulates the release of oxytocin from the corpus luteum in vivo (Flint & Sheldrick, 1982) (Evrard, Leboulleux & Hermier, 1978;Fletcher & Niswender, 1982), but other investigators have observed that PGF-2a stimulates progesterone secretion by dispersed bovine luteal cells (Hixon & Hansel, 1979 (Kaltenbach, Graber, Niswender & Nalbandov, 1968), and prolong the oestrous cycle in intact ewes (Karsch et al, 1971). In addition, administration of an antiserum to LH reduces the weight and progesterone content of corpora lutea of sheep (Fuller & Hansel, 1970 (Fitz et al, 1982).…”

Continuous infusion of oxytocin prevents induction of uterine oxytocin receptor and blocks luteal regression in cyclic ewes

“…The corpora lutea of sheep and cattle contain high concentrations of oxytocin (Wathes & Swann, 1982;Flint & Sheldrick, 1982a;Fields, Eldridge, Fuchs, Roberts & Fields, 1983) which is secreted into the ovarian vein (Flint & Sheldrick, 1982b). Secretion is stimulated by analogues (Flint & Sheldrick, 1982b, 1983.…”

“…The corpora lutea of sheep and cattle contain high concentrations of oxytocin (Wathes & Swann, 1982;Flint & Sheldrick, 1982a;Fields, Eldridge, Fuchs, Roberts & Fields, 1983) which is secreted into the ovarian vein (Flint & Sheldrick, 1982b). Secretion is stimulated by analogues (Flint & Sheldrick, 1982b, 1983. The significance of luteal oxytocin secretion in response to PGF-2a may lie in the positive feedback loop constituted by this process together with the release of PGF-2a from the uterus in response to oxytocin (Flint & Sheldrick, 1983;Sheldrick & Flint, 1983a).…”

Função do interferon-tau durante o reconhecimento materno da gestação em ruminantes

“…Adicionalmente, a estimulação luteal pela PGF2 aumenta a liberação de ocitocina luteal (FLINT & SHELDRICK, 1982), que potencializa a liberação de PGF2 uterina (WATHES & LAMMING, 1995) e luteal (SHIRASUNA et al, 2007).…”