Assessment of insulin secretion in humans under physiological conditions has been a challenge because of its complex interplay with insulin action and hepatic insulin extraction. The possibility of simultaneously assessing beta-cell function, insulin sensitivity, and hepatic insulin extraction under physiological conditions using a simple protocol is appealing, since it has the potential to pro...

OBJECTIVE Insulin control of fatty acid metabolism has long been deemed dominated by suppression of adipose lipolysis. The goal of the present study was to test the hypothesis that this single role of insulin is insufficient to explain observed fatty acid dynamics. METHODS AND RESULTS Fatty acid kinetics were measured during a meal tolerance test and insulin sensitivity assessed by intravenou...

On the basis of results obtained from an oral glucose tolerance test, (OGTT), twenty patients with gonadal dysgenesis were classified as normal (N = 8) and diabetic (N = 12). The two groups of patients were further tested by a rapid intravenous glucose injection, a tolbutamide test, an insulin sensitivity test and an oral amino acid load. Fasting levels of plasma growth hormone (GH) were normal...

The half-life of an intravenously injected bolus of intralipid 20% was measured in normal rats in order to asess its relationship to reticuloendothelial system (RES) activity. Groups of animals were studied following various treatments, and the results compared to measurement of carbon clearance in similar groups. The RES effects of silica and C parvum were confirmed by the carbon clearance tes...

OBJECTIVE The aim of this study was to examine the association of physical activity with glucose tolerance and resting energy expenditure (REE) among adolescents. RESEARCH DESIGN AND METHODS Subjects were 32 male and female adolescents aged 12-18 years. Intravenous glucose tolerance (K(g)) and REE were assessed under inpatient conditions after an overnight fast. K(g) was determined as the inv...

The aim of this experiment was to evaluate the impact of selection for greater muscling on whole body insulin responsiveness in cattle, as reflected by greater uptake of glucose in response to constant insulin infusion and greater glucose disappearance following an intravenous glucose tolerance test. This study used 18-month-old steers from an Angus herd visually assessed and selected for diver...

Serum human growth hormone (HGH), serum immunoreactive insulin (IRI), plasma free fatty acids, and blood glucose were measured during intravenous glucose and intravenous tolbutamide tolerance tests in 13 normal and 13 prediabetic (offspring of two diabetic parents) males, closely matched for weight and age. Only prediabetics with normal glucose tolerance during oral, intravenous, and cortisone-...