Ovarian and immunological responses to alternating exogenous gonadotropin regimens in the ocelot (Leopardus pardalis) and tigrina (Leopardus tigrinus)
Abstract 10.1002/zoo.20049.abs Exogenous gonadotropins frequently are used to stimulate ovarian follicular growth and ovulation in mammalian species, including felids. However, repeated exogenous gonadotropin treatment can result in decreased ovarian responsiveness due to antibody formation. In this study, our objectives were to assess the effectiveness of alternating gonadotropin regimens on ovarian responses in ocelots and tigrinas, […]
Analysis of urinary immunoreactive steroid metabolites and gonadotropins for characterization of the estrous cycle, breeding period, and seasonal estrous activity of captive killer whales (Orcinus orca)
Abstract 10.1002/zoo.1430120204.abs To increase the basic understanding of killer whale (Orcinus orca) reproductive physiology necessary for the development of artificial breeding programs, we utilized radioimmunoassays (RIA) to detect urinary immunoreactive steroid metabolites (pregnanediol-3α-glucuronide [PdG] and estrone-conjugates [EC]) and gonadotropins (luteinizing hormone [LH] and follicle-stimulating hormone [FSH]) in urine samples from six female killer whales. Urine […]
Seasonal cycles in testicular activity, gonadotropin, and thyroxine in the painted turtle, Chrysemys picta, under natural conditions
Plasma levels of testosterone (T), thyroxine (T4) and follicle-stimulating hormone (FSH) were measured in a field population of the painted turtle, Chrysemys picta, in Michigan. All three hormones showed pronounced seasonality; plasma luteinizing hormone (LH) remained nondetectable. Plasma T and FSH concentrations were highly correlated and exhibited biphasic cycles with peaks in spring and fall, […]
Seasonal and stress related changes in plasma gonadotropins, sex steroids, and corticosterone in the bullfrog, Rana catesbeiana
Studies of seasonal gonadal cycles combined with direct measurements of plasma levels of the two gonadotropins (FSH and LH), several gonadal steroids (estrogen, E; progesterone, P; testosterone, T; and 5 alpha-dihydrotestosterone, DHT), and the interrenal steroid corticosterone (B) were made in male and female bullfrogs in central California over a 5-year period (between 1976 and […]