Long-term plasma progesterone profiles in captive macaques (macaca fascicularis)

Abstract

Five adult female long-tailed macaques (Macaca fascicularis} were studied in a laboratory environment soon after capture for a 14-month period to determine the relationship between ovarian cyclicity and captivity, and to establish whether there was seasonal fluctuation in ovarian function under local conditions. Menstrual cycle lengths were established for each animal using both vaginal swabbing and progesterone determination. Plasma progesterone was measured by radioimmunoassay with a sensitivity of ~ 0.25 ng/ml and an intra- and inter-assay coefficients of variation of 6.7% (n=30) and 16.9% (n=22), respectively. Regular ovarian activity was observed in 3 animals, with a mean (± S.D.) ovarian cycle length of 25.5 ±. 1.8 (n=17), 32.8 ±. 6.3 (n=l1) and 31.3 ±. 3.8 (n=11) days, respectively. Long-term disruption of ovarian cyclicity was observed in two animals; one animal showed numerous anovulatory cycles with a mean length of 70.3.± 37.3 (n=6) days, while the other had amenorrhea exceeding 200 days. With twice weekly observations, the present study suggests that serial plasma progesterone determination is a better indicator of ovarian cyclicity than vaginal swabbing. It was found that captivity was associated with ovarian dysfunction in some but not all animals. No seasonal fluctuation in ovarian function was observed