Kim, Jason K., Cheol S. Choi, and Jang H. Youn. Acute effect of growth hormone to induce peripheral insulin resistance is independent of FFA and insulin levels in rats. Am. J. Physiol. 277 (Endocrinol. Metab. 40): E742–E749, 1999.—To examine whether growth hormone (GH) induces peripheral insulin resistance by altering plasma free fatty acid (FFA) or insulin levels, the effects of GH infusion on...

We have previously demonstrated that physiological hyperinsulinemia in normotensive humans increases sympathetic nerve activity but not arterial pressure since it also causes skeletal muscle vasodilation. However, in the presence of insulin resistance and/or hypertension, insulin may cause exaggerated sympathetic activation or impaired vasodilation and thus elevate arterial pressure. This study...

1. Insulin was infused into young male rats in the postabsorptive state. Rates of protein synthesis in skeletal muscle were determined during the final 10 min of infusion from the incorporation of label into protein after intravenous injection of a massive dose of [3H]phenylalanine. Rates of synthesis were not altered during the first 10 min of insulin infusion, but were increased significantly...

Systemic hyperinsulinaemia induces vasodilatation in human skeletal muscle. This effect is gradual in onset, and at low insulin levels not maximal until at least 3 h. To investigate whether the vasodilator response to insulin results from a direct vascular effect, we infused insulin directly into the cannulated brachial artery (perfused forearm technique) in a total of 30 experiments in 20 heal...

We previously showed that insulin has a profound effect to suppress pyruvate dehydrogenase kinase (PDK) 4 expression in rat skeletal muscle. In the present study, we examined whether insulin's effect on PDK4 expression is impaired in acute insulin-resistant states and, if so, whether this change is accompanied by decreased insulin's effects to stimulate Akt and forkhead box class O (FOXO) 1 pho...

Continuous intravenous insulin and dextrose infusions were used in managing various diabetic emergencies. Standard and constant rates of insulin and dextrose infusion resulted in satisfactory control of blood glucose concentrations during labour, after major surgery, and in patients recovering from ketoacidosis (average insulin infusion rates 1, 2, and 3 U/h respectively). Higher infusion rates...

Splanchnic glucose uptake (SGU) plays a major role in the disposal of an oral glucose load (OGL). To investigate the effect of an elevated plasma free fatty acid (FFA) concentration on SGU in patients with type 2 diabetes, we measured SGU in eight diabetic patients (mean age 51 +/- 4 years, BMI 29.3 +/- 1.4 kg/m(2), fasting plasma glucose 9.3 +/- 0.7 mmol/l) during an intravenous Intralipid/hep...

To determine whether abnormal kinetics of insulin's biologic actions contribute to the overall insulin resistance in obesity, we compared the rate of activation and deactivation of insulin's effects to stimulate glucose disposal rate (Rd) and inhibit hepatic glucose output (HGO) in 12 nonobese and 10 obese subjects using the euglycemic clamp technique at insulin infusion rates of 15, 40, 120, a...

To examine the molecular mechanisms by which plasma amino acid elevation impairs insulin action, we studied seven healthy men twice in random order during infusion of an amino acid mixture or saline (total plasma amino acid approximately 6 vs. approximately 2 mmol/l). Somatostatin-insulin-glucose clamps created conditions of low peripheral hyperinsulinemia ( approximately 100 pmol/l, 0-180 min)...

1. The renal effects of insulin may play a central role in the association between insulin resistance, hypertension and hyperuricaemia. After a 2-h baseline period, we investigated the effects of exogenous insulin for 4 h (50 m-units h-1 kg-1) on fractional renal sodium and urate excretion in 13 healthy subjects, using the euglycaemic clamp and lithium clearance technique, and performed a contr...