Body fat distribution with long-term dietary restriction in adult male rhesus macaques.

Dietary restriction (DR) is the only intervention that has been shown to increase average and median life span in laboratory rodents. The effect of long-term, moderate DR on body composition and fat distribution was evaluated in male rhesus monkeys. Thirty animals (8-14 years of age)fed either 30% less than baseline intake (R, n = 15) or allowed to eat to satiety (C, n = 15), have been assessed semiannually using somatometrics and dual-energy alpha-ray absorptiometry (DXA)for 7.

Energy expenditure of adult male rhesus monkeys during the first 30 mo of dietary restriction.

Energy expenditure, activity, and body composition were measured in 30 adult male rhesus monkeys used in a study having the long-term goal of determining the effects of moderate dietary restriction (DR) on aging. All animals were fed a defined diet, with the restricted animals maintained at approximately 70% of the caloric intakes of the controls. After 12 mo of DR, body fat mass of restricted monkeys was 33% less than that of controls (P = 0.

Effects of adrenal medulla transplantation into the third ventricle on the onset of puberty in female rhesus monkeys.

To test the hypothesis that prepubertal exposure of LHRH neurons to a source of catecholamines and neuropeptides accelerates the onset of puberty, we examined the effects of autologous adrenal transplantation into the base of the third ventricle of the brain in juvenile female rhesus monkeys at 11-13 months of age. The adrenal medulla, which contains catecholamines and neuropeptide Y (NPY), was cut into small pieces and mixed with gelfoam in artificial CSF and injected into the third ventricle, adjacent to LHRH neurons and their neuroterminals. Sham control monkeys received artificial CSF with gelfoam alone.

Age and sex differences in body size and composition during rhesus monkey adulthood.

Body size and composition were measured in forty-one adult Rhesus monkeys (Macaca mulatta) in order to characterize changes that occur during later life for both genders. Data were obtained by traditional somatometric techniques and by dual-energy X-ray absorptiometry. Representative monkeys were chosen within six categories defined by age (Young Adult, 6-9 year-old; Middle Aged, 15-19 year-old; Older Adult, 26-30 year-old), and sex.

Control of luteinizing hormone-releasing hormone pulse generation in nonhuman primates.

1. The pulsatile release of luteinizing hormone-releasing hormone (LHRH) is critical for reproductive function. However, the exact mechanism of LHRH pulse generation is unclear.

A primary cell culture system of luteinizing hormone releasing hormone neurons derived from embryonic olfactory placode in the rhesus monkey.

The purpose of this study is to establish a primary LHRH cell culture system using embryonic olfactory placode and to examine whether LHRH cells derived from olfactory placode and the migratory pathway of LHRH neurons mature in vitro. Six monkey fetuses at the ages of E34-E36 were delivered surgically and the area including the olfactory placode (PL) and the areas that encompass the migratory pathway (MP) were dissected out. The tissues were cut into small pieces and plated on collagen- or poly-L-lysine-coated glass coverslips in medium M199.

Infusion of neuropeptide Y into the stalk-median eminence stimulates in vivo release of luteinizing hormone-release hormone in gonadectomized rhesus monkeys.

Studies in the rat and rabbit indicate that facilitatory effects of neuropeptide Y (NPY) as well as norepinephrine (NE) on LH and LHRH release are dependent on the presence of the ovarian steroid estrogen. However, we have previously found the NE and an alpha-1-adrenergic agonist are both stimulatory to pulsatile LHRH release in ovariectomized rhesus monkeys. In the present experiment the effects of NPY on LHRH release were examined in conscious monkeys using a push-pull perfusion method.

The effects of topical diazoxide on hair follicular growth and physiology of the stumptailed macaque.

Diazoxide, an anti-hypertensive agent, has diverse pharmacologic effects; hypertrichosis, hyperglycemia associated with suppression of insulin release, and elevation of serum levels of androgens. Taking advantage of the hypertrichotic side effects of diazoxide, we examined the effect of topical application of the drug on hair regrowth in the bald frontal scalp of stumptailed macaques (Macaca arctoides); we also monitored systemic side effects. Using 7 adult stumptails, we applied diazoxide (5% solution in a vehicle) topically on the bald frontal scalp, once a day, 5 days per week.

In vivo release of luteinizing hormone releasing hormone increases with puberty in the female rhesus monkey.

To determine the regulatory mechanism of the LHRH release associated with puberty, episodic release of LHRH from the stalk-median eminence was measured using a push-pull perfusion technique in conscious prepubertal and peripubertal female monkeys. After insertion of a push-pull cannula into the stalk-median eminence, a modified Krebs-Ringer phosphate buffer solution was infused through the push-cannula, and perfusates were collected through the pull-cannula at 200 microliters/10 min. LHRH in perfusates was determined by RIA.

Effects of ovarian hormones on eating behaviors, body weight, and glucoregulation in rhesus monkeys.

The influences of ovarian hormones on food intake, taste preferences, and glucoregulation were examined in intact and ovariectomized rhesus monkeys. Intake of intact monkeys was lowest in the preovulatory stage of the cycle, when estrogen levels are elevated, and exogenous estradiol transiently suppressed food intake of ovariectomized monkeys in a dose-related manner, confirming previous observations. Progesterone treatment did not affect food intake when given alone, but it did attenuate the effect of estradiol when both hormones were given concurrently.

Androgenic influences on body size and composition of adult rhesus monkeys.

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.