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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(More)
The nature and extent of somatostatin-induced inhibition of pancreatic endocrine secretion were studied by administration of a number of stimuli of either glucagon or insulin to over night fasted baboons with and without an infusion of linear somatostatin. The stimuli for acute-phase insulin release were intravenous pulses of glucose, tolbutamide,(More)
Studies of insulin binding to skeletal muscle, performed using sarcolemmal membrane preparations or whole muscle incubations of mixed muscle or typical red (soleus, psoas) or white [extensor digitorum longus (EDL), gastrocnemius] muscle, have suggested that red muscle binds more insulin than white muscle. We have evaluated this hypothesis using cryostat(More)
Somatostatin, a hypothalamic peptide that inhibits the secretion of pituitary growth hormone, inhibits basal insulin secretion in fasted cats and rats. In fasted baboons both basal and arginine-stimulated secretion of insulin and glucagon are inhibited. Somatostatin appears to act directly on the endocrine pancreas. The action is dose-related, rapid in(More)
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,(More)
In vivo beta-cell function tests are used increasingly in humans during the preclinical phase of insulin-dependent diabetes mellitus (IDDM), but the severity of the beta-cell loss responsible for the abnormalities seen in these tests is unknown. We have measured several physiological beta-cell function tests--fasting plasma glucose, glucose disappearance(More)
We have compared the effects of pulsatile and continuous glucagon administration on hepatocyte glucose production in order to clarify the physiological role of pulsatile hormone secretion. Two identical columns containing freshly isolated rat hepatocytes mixed with polyacrylamide gel beads were perifused with oxygenated tissue culture medium. A fixed total(More)
It is controversial whether stimulation of glucagon secretion by hypoglycemia or suppression by hyperglycemia is a direct effect of glucose on the A cell or whether it is mediated indirectly through the B cell. To determine the role of the B cell in the mediation of glucagon secretion adolescent male baboons were studied before and after successive(More)
To determine whether galanin is a pancreatic sympathetic neurotransmitter regulating insulin secretion in the baboon, as it is in the dog, we evaluated galanin for inhibitory effects on insulin secretion in conscious baboons, determined if baboon pancreatic islets are innervated by galaninergic fibers using immunohistochemistry, and measured galanin content(More)
Anorexia and weight loss produced by estradiol (E2) may involve altered expression of neuropeptide Y (NPY) in the hypothalamus. We tested this hypothesis using ovariectomized (OVX) rats by replacing E2 with SILASTIC brand capsule implants and measuring NPY messenger RNA (mRNA) levels in the arcuate nucleus by in situ hybridization. To equalize the effects(More)