Nonhuman Primate Models of Menopause (Part 21)
Additional similarities are seen in nonreproductive measures between aging human and NHP females. These include age-related changes in metabolic parameters of rhesus monkeys and baboons that are similar to those in humans, such as gains in weight and increases in relative body fat content, with tendencies toward abnormal glucose tolerance and increased insulin resistance, up until old age, when body weight and fat decline. Levels of DHEA decline with age in rhesus monkeys, as is well established in humans. The apparent similarity of the internal temperature regulation system of NHPs and humans suggests that the NHP may be an appropriate model of hot flashes associated with menopause, permitting both invasive experimentation to understand the underlying biological mechanisms and potential preventative and interventional approaches to reduce the incidence of hot flashes in both peri- and postmenopausal women. my canadian pharmacy online
Older cycling baboons show increased LDL and decreased HDL cholesterol relative to levels seen when 5 yr younger, suggesting an age-related increase in risk factors for cardiovascular disease. Although baboons appear to be less susceptible to atherogenesis than rhesus monkeys, fatty streaks, occasional fibrous plaques, and an atherogenic lipid profile were observed in baboons associated with a high-fat diet and irregular menstrual cycles, increased age, or increased obesity. Plasma LDL cholesterol and fatty streaks were responsive to estrogen treatment in ovariec-tomized baboons. Estrogen also reduces coronary artery atherosclerosis and reverses acetylcholine-induced vasoconstriction in ovariectomized cynomolgus monkeys fed a high-fat diet, but without a large effect on plasma lipid levels. Age-related changes in bone density have been reported; however, more studies are needed before we can determine whether age- or menopause-related changes occur in NHPs parallel to those in humans.