Research Approaches to Explore Apparent Differences Between NHP and Human Menopause/Aging
Important differences between NHP and human females must be considered. First, the length of the postmenopausal life span is considerably shorter in NHPs, probably not more than 6-7 yr in rhesus monkeys and baboons and less than 1 yr in chimpanzees, and relative to women, NHPs are much older when experiencing the menopausal process (Table 1). Whether this substantial difference in total and postmenopausal life span between NHPs and women results from diet or environmental factors, or whether this is a true genetically determined difference, is unclear. Are there ways to increase the average and maximum life span of these NHP species? We know that at the start of the 20th century, few women lived much past the age of menopause (~50 yr). canadian neighbor pharmacy online
With the advent of enhanced knowledge regarding health-related biological processes and improved medical procedures, the average life span of women has increased substantially, whereas the age of menopause has not changed. Can something similar be done for NHPs? Perhaps through improved husbandry, diet, and medical care, their average life span can also be increased substantially, so that they enter menopause at a relatively younger age.
Second, the timing and magnitude of changes in several key hormones related to human menopause appears to be different in NHPs. Preliminary data using a small cohort of rhesus monkeys suggests that the sentinel monotropic increase in FSH secretion and declining inhibin B level reported in normally cycling, middle-aged women did not occur in rhesus monkeys until cycles become irregular. This finding needs to be replicated with larger numbers of animals. Also, increased estrogen levels seen in perimeno-pausal women relative to midreproductive-aged women have not been observed in irregularly cycling rhesus monkeys and baboons.