Premium
THE EFFECTS OF ENDOGENOUS AND ADDED INSULIN ON THE TIME‐COURSE OF GLUCOSE UPTAKE BY THE ISOLATED PERFUSED RAT HEART
Author(s) -
Fisher R. B.,
'me>O'Brien J. A.
Publication year - 1972
Publication title -
quarterly journal of experimental physiology and cognate medical sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0033-5541
DOI - 10.1113/expphysiol.1972.sp002147
Subject(s) - perfusion , insulin , medicine , endogeny , endocrinology , glucose uptake , chemistry
A new method for measurement at short intervals of uptake or production of metabolites by a perfused heart has been applied to the study of the time‐course of glucose utilization. In the presence of high concentrations of insulin (100 mU/ml.) glucose utilization was constant from the beginning of perfusion at all concentrations of glucose. In the absence of added insulin, when the perfusate glucose concentration was greater than 1 mM, glucose utilization decreased by more than 20% to reach a constant rate after up to one hour of perfusion. At glucose concentrations below 0·5 mM, glucose utilization without insulin was constant, or nearly so, throughout perfusion. These results suggest that endogenous insulin, which may be relatively ineffective in promoting glucose utilization at low glucose concentrations, influences the properties of the isolated heart longer than is generally supposed. By choice of a suitable infusion rate it is possible to use the new method to study metabolic rates at substrate concentrations which it was not previously feasible to use.