In overnight fasted rhesus monkeys, synchronous, regular oscillations occurred in the plasma concentrations of glucose, insulin, and glucagon. The oscillations displayed a period averaging 9 minutes. The amplitudes for insulin and glucagon were ten and five times greater than for glucose. Insulin cycled in and glucagon out of phase with glucose. In baboons, oscillations of glucose and insulin were smaller than in rhesus monkeys, while in man, regular oscillations were not observed.

Obesity was studied in a colony of 873 Macaca nemestrina to establish tools for epidemiologic studies, to examine a genetic form of obesity, to document age/sex relationships to obesity, and to compare metabolic profiles of obese and normal monkeys. Age/weight growth curves were analyzed to select the most obese monkeys and age- and sex-matched normal controls. Degree of adiposity was determined using tritiated water for estimation of lean body mass. Body weight, anterior trunk height, and abdominal and triceps skinfolds were measured. Fasting insulin, fasting free fatty acids, and glucose disappearance rate were determined. The results give evidence of similarities between macaque and human obesity.

17 human subjects ate 20-min. meals of Metrecal through a straw connected to a hidden reservoir. Oral preloads of Metrecal were administered before the meals, and these varied 20-120% of the amount of the base-line meal intake and were given 1-120 min. before the meal. Test-meal intake was depressed as a function of the size of the preload; however, the subjects did not take the preload fully into account and they overate. Depression of intake was maximal 1-5 min. for some subjects and 15-30 min. for others. Subjective ratings of hunger paralleled the variations in intake produced by preloading. The results are discussed in terms of the joint operation of oropharyngeal and gastric postingestional factors.

No abstract

No abstract