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Menopause in female rhesus monkeys
Author(s) -
Walker Margaret L.
Publication year - 1995
Publication title -
american journal of primatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.988
H-Index - 81
eISSN - 1098-2345
pISSN - 0275-2565
DOI - 10.1002/ajp.1350350106
Subject(s) - menopause , ovulation , physiology , luteinizing hormone , endocrinology , medicine , basal (medicine) , hormone , menstruation , endocrine system , biology , insulin
Abstract Fifteen female rhesus monkeys ( Macaca mulatto ), ranging in age from 8 to 34 years, were studied for one year to characterize the endocrine and menstrual changes associated with menopause in this species. Five monkeys were premenopausal; these younger monkeys, ages 8–11 years, menstruated and showed cyclic ovarian activity during the 12–month study period, as evidenced by menses and periodic elevations of serum estradiol (E 2 ) and luteinizing hormone (LH) concentrations. Four females, ages 24–26 years, were in transition to menopause. Two of these perimenopausal females menstruated and secreted E 2 and LH in a periodic fashion; the other two females showed elevated LH concentrations, consistently low E 2 levels, and no evidence of menstruation. Six females, ages 27–34 years, were clearly postmenopausal; LH concentrations were high, whereas E 2 concentrations were uniformly low. There was a significant inverse correlation between basal E 2 concentrations and age, and a significant positive correlation between age and LH concentrations across all 15 animals. Hormonal changes indicative of ovulation, when they occurred, were generally restricted to the winter and early spring months. Histological analysis of ovaries from four postmenopausal females revealed little or no evidence of active folliculogenesis. These data indicate that menopause in female rhesus monkeys does not occur until the second half of thethird decade of life. © 1995 Wiley‐Liss, Inc.