Influence of growth hormone on glucose-glucose 6-phosphate cycle and insulin action in normal humans

Autor: Patrick M. Bell, D. P. Rooney, R. D. G. Neely, Elisabeth R. Trimble, A. B. Atkinson, Brian Sheridan, N. P. Bell
Rok vydání: 1992
Předmět:
Zdroj: American Journal of Physiology-Endocrinology and Metabolism. 263:E980-E987
ISSN: 1522-1555
0193-1849
DOI: 10.1152/ajpendo.1992.263.5.e980
Popis: Increased activity of the hepatic glucose-glucose 6-phosphate (G/G-6-P) cycle is associated with hepatic and peripheral insulin resistance in acromegaly. To determine whether a similar association occurs after short-term growth hormone (GH) elevation within the physiological range, two-step euglycemic hyperinsulinemic clamps were performed in normal human males after 12-h GH (2.2 ng.kg-1 x h-1) and control infusions. G/G-6-P cycle activity and endogenous glucose production (EGP) were determined by [2-3H]- and [6-3H]-glucose using labeled exogenous glucose infusions and selective enzymatic detritiation. GH increased levels of circulating lipid intermediates despite a twofold increase in basal insulin (P < 0.005), but plasma glucose, EGP, and G/G-6-P cycle activity were unchanged. GH impaired insulin suppression of EGP and lipid intermediates and impaired insulin stimulation of glucose disposal, but G/G-6-P cycle activity was unchanged. We conclude that increased activity of the G/G-6-P cycle does not contribute to the hepatic insulin resistance induced by GH under these conditions but that changes in fatty acid metabolism may be partly responsible for the impairment in hepatic and peripheral insulin action.
Databáze: OpenAIRE