Fredrick Stormshak

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An experiment was conducted to determine whether feeding rumen-protected fatty acids (FA) to postpartum heifers would increase plasma concentrations of linoleic acid and PGF2, metabolite (PGFM), shorten the interval from calving to first increase in plasma concentrations of progesterone (P4), and increase pregnancy rate relative to controls. Hereford x(More)
Progesterone (P4) has been reported to inhibit oxytocin (OT) binding to its receptor in isolated murine endometrial membranes. The purpose of the present research was to 1). examine the in vivo and in vitro effect of P4 on the binding of OT to its receptor in the ovine endometrium and 2). determine whether the endometrial plasma membranes have high-affinity(More)
We tested the hypothesis that progesterone (P(4)) acts at a local level to inhibit luteal apoptosis. Initial experiments employed aminoglutethimide, a P450 cholesterol side-chain cleavage inhibitor, to inhibit steroid synthesis. Cultured bovine luteal cells were treated with aminoglutethimide (0.15 mM) +/- P(4) (500 ng/ml) for 48 h. Luteal cells were(More)
It has been established that nuclear receptors mediate the action of estrogens and progestins in regulating gene expression in the hypothalamic-hypophyseal-gonadal axis of domestic animals during various reproductive states. Results of recent in vitro studies suggest that estradiol-17beta and progesterone can act non-genomically to affect signal(More)
Progesterone and estrogens play key roles in regulating various physiological phenomena related to normal growth, development, and reproduction of domestic animals. This review focuses on the mechanisms by which progesterone and estrogens regulate the reproductive processes in these animals. The majority of research on the actions of progesterone and(More)
Cytogenetic characteristics of ova surgically recovered from 19 first-estrous (pubertal) gilts were compared with those from 24 third-estrous gilts. Mean percentage recovery of ova was 82.1 +/- 2.9%. A total of 159 and 203 ova from first- and third-estrous gilts, respectively, were evaluated. Gilts at first and third estrus ovulated more mature ova(More)
A review of the current state of knowledge of oxytocin production by the preovulatory follicle and corpus luteum is presented. Corpora lutea of a number of mammalian species have been found to synthesize oxytocin. However, the synthesis and secretion of this nanopeptide by the corpus luteum of the ruminant has been most extensively studied because of the(More)
Effects of lipid infusion into postpartum (PP) beef heifers on plasma concentrations of linoleic acid and prostaglandin (PG) F(2alpha) metabolite (PGFM), days to first estrus, and subsequent pregnancy rate were examined. Treatments (n = 5 per group) of 1 L intralipid (20% soybean oil; IL), 1 L 50% dextrose (DEXT; isocaloric to IL), 0.5 L intralipid (0.5(More)