No abstract

A practical approach for monitoring urinary estrogen and luteinizing hormone (LH) in various primate species is described. Total immunoreactive estrogen (E() levels, measured without chromatography, provided a convenient estimation of estrone, estradiol and estriol as the sum of their separated parts. Bioactive LH in urine was measured by the rat interstitial cell testosterone (RICT) in vitro bioassay. Correction for urinary creatinine content allowed for the comparison of hormone production from small volumes of urine collected from single daily voidings. Using these methods, urinary Et and LH profiles through the reproductive cycles of a human, gorilla, chimpanzee and capuchin monkey have been determined.

Immunoreactive estrogen and luteinizing hormone/chorionic gonadotropin (LH/CG) bioactivity have been measured throughout pregnancy in diverse primate species with a simple methodological approach utilizing small volumes of urine collected randomly. Total immunoreactive estrogen levels and the relative abundance of component estrogens (estrone, estradiol and estriol) at various stages of gestation were compared in the human, orangutan, pygmy chimpanzee, Doue langur and capuchin. Measurement of urinary LH/CG bioactivity enables an earlier detection of pregnancy when compared to the nonhuman primate pregnancy test. The methods described provide a practical and non-stressful way to detect and monitor pregnancy in widely divergent primate species.

Exogenous luteinizing hormone-releasing hormone (LH-RH) administered in a wide range of doses (0.2-25 μg) to intact male marmoset monkeys induced a marked increase in plasma luteinizing hormone (LH) concentrations. Maximum LH concentrations achieved after injection of LH-RH occurred progressively later as the dosage increased. Bilateral orchidectomy significantly enhanced pituitary responsiveness to a standard dose (2.0 μg) of LH-RH, whereas the introduction of oestradiol-17β implants effectively inhibited the response. LH-RH-induced LH release after gonadectomy (with and without oestradiol- 17β treatment) was similar in males and females. The use of marmosets for appropriate investigation into the physiological role of LH-RH in controlling LH secretion in primates is proposed.