High concentrations of polychlorinated biphenyls (PCBs) in polar bears from Svalbard have increased concern for that population's reproductive health. We examined whether there were associations between the plasma concentrations of PCBs and reproductive hormones [progesterone (P4)] and 17 beta-estradiol (E2)] in free-living female polar bears from Svalbard. Concentrations of P4 depended on repr...

Hypoxia has been suggested to enhance progesterone (P4) synthesis in luteinizing granulosa cells (GCs), but the mechanism is unclear. The present study was designed to test the hypothesis that the hypoxia-induced increase in P4 synthesis during luteinization in bovine GCs is mediated by hypoxia-inducible factor 1 (HIF-1). GCs obtained from small antral follicles were cultured with 2 µg/ml insul...

The reactions of [CpMoH(κ(3)-P4)] (2; P4 = meso-o-C6H4(PPhCH2CH2PPh2)2) with protic acids gave [CpMo(κ(4)-P4)](+) (4(+)) via the intermediary formation of [CpMoH2(κ(3)-P4)](+). Treatment of 2 with iodine provided the cationic complex [CpMoHI(κ(3)-P4)][I] (5[I]). Early-late heterobimetallic complexes of the type [CpMoH(μ-P4-1κ(3):2κ)MLnCl] (MLn = Ru(Hmb)Cl (6), Ir(η(5)-C5Me5)Cl (7), Rh(cod), Ir(...

The aim of the present study was to investigate the changing profiles of plasma metabolic hormones during the ovarian cycles of beef and dairy cattle. We used 16 non-pregnant, non-lactating Japanese Black beef cattle (6 heifers and 10 cows; parity=2.3 +/- 0.8) and 12 multiparous Holstein dairy cows (parity=3.0 +/- 0.3). Blood samples for hormonal analysis (growth hormone, GH; insulin-like growt...

In the present study we examined whether local transfer of intranasally administrated tritiated progesterone (3H-P4) would increase its concentration in blood supplying the brain and hypophysis in comparison with other organs. Additionally, the effect of estrous cycle on the P4 transfer was evaluated on isolated gilts' heads. In the first experiment 3H-P4 was instilled into the nasal cavities o...

We examined the participation of the intraluteal levels of progesterone (P4) and prostaglandin F2 alpha (PGF2 alpha) in the induction of luteolysis by LH and its relationship with the induction of the 20 alpha-hydroxysteroid dehydrogenase activity (20 alpha-HSD). Subcutaneous administration of four doses of 10 microgram ovine LH (oLH) at 0800, 0900, 1000 and 1100 h on day 19 of pregnancy induce...

Noninvasive fecal assays were used to study steroid metabolism and ovarian activity in several felid species. Using the domestic cat (Felis catus) as model, the excretory products of injected [14C]estradiol (E2) and [14C]progesterone (P4) were determined. Within 2 days, 97.0 +/- 0.6% and 96.7 +/- 0.5% of recovered E2 and P4 radioactivity, respectively, was found in feces. E2 was excreted as unc...

Uterine adenogenesis in the neonate is critical as uterine glands are essential for pregnancy in adult ruminants. The uterus is stimulated by estrogens (E2) and progesterone (P4) that prepare it to respond to biochemical signals from the conceptus (embryo/fetus and placenta). Interferon tau (IFNT) is responsible for pregnancy recognition and modification of uterine gene expression including sen...

A cross sectional study was done in seventy-four beagle dogs from one to twelve years of age. Gingivitis, calculus, plaque, loss of attachment, pocket depth and width of keratinized gingiva were scored and descriptive statistics calculated. Gingivitis differed very little in the maxillairy and mandibuiar incisor and canine regions at differing ages, while it was more severe on the buccal gingiv...