Androgenic influences on body size and composition of adult rhesus monkeys

Abstract

The effects of daily treatment with testosterone propionate (TP, 2 mg/kg) and dihydrotestosterone propionate (DHTP, 2 mg/kg) were examined in rhesus monkeys in three experiments. In experiments 1 and 2, males and females gonadectomized in infancy, and female pseudohermaphrodites produced by prenatal exposure to TP or DHTP and gonadectomized postpubertally, were studied in conjunction with intact males (IM). The IM group was heavier in adulthood than the three gonadectomized groups, which did not differ in body weight from each other. Genetic males had greater crown-rump length than genetic females. Treatment of the gonadectomized groups with TP produced large increases in body mass (averaging approximately 50%) that were attributable to accretion of lean tissue. This effect did not differ significantly between males and females. In experiment 3, additional groups of males that had been castrated as infants were given daily injections with DHTP or oil. The DHTP treatment resulted in increases in body size that were not different from those seen following TP treatment. When TP and DHPT treatments were discontinued, body weights and dimensions reverted to base-line values. Increased body size induced by TP and DHTP was accomplished without reliable increases in food intake. Because testosterone (T) is metabolized to dihydrotestosterone (DHT), while DHT cannot be converted to T, these results show that both T and DHT are effective anabolic hormones in rhesus.

Age‐ and gender‐related changes in body size, adiposity, and endocrine and metabolic parameters in free‐ranging rhesus macaques

“…indicating greater fat deposition in females. In contrast, lean body mass, as reflected in chest and limb circumference (Kemnitz et al, 1988) was greater in males. In human beings, there is a clear gender dimorphism with respect to total body fat, as reflected in both indirect and direct measurements of body fat (Lohman, 1981;Brown and Konner, 1987).…”

“…Moreover, a similar ratio to WEIR, the ratio of the circumference of the abdomen to the circumference of the thigh (wsthhigh ratio), is highly correlated with body fat in rhesus macaques (Kemnitz et al, 1989). Indices such as chest and upper-arm circumference, on the other hand, are good predictors of lean body mass (Kemnitz et al, 1988). A limitation with these data is most measurements have been collected from obese monkeys; baseline information from normal, well-nourished animals is limited and does not encompass the entire life span of the individual (Coehlo, 1985).…”

Nonhuman Primate Models of Menopause Workshop1

“…Body weight was reasonably stable from 10 to 20 yr of age, with males weighing more than females [34]. Rhesus monkeys older than 25 yr tended to lose weight, primarily from loss of skeletal muscle [35]. Females had greater body fat relative to body weight [36].…”

Sex differences in the physiology of eating

“…The role of androgens in eating in anthropoid primates is unknown. In rhesus monkeys, testosterone treatment failed to significantly affect eating despite producing large (ϳ50%) increases in body weight and lean body mass in 7-9 yr-old monkeys that had been orchiectomized at 0 -3 mo of age (375). The potential influences of the early orchiectomy and the long orchiectomy-treatment delay on the results were not assessed.…”