Increase of glomerular filtration rate and renal plasma flow by insulin‐like growth factor‐1 during euglycaemic clamping in anaesthetized rats

Abstract

Renal function was studied in anaesthetized rats receiving i.v. infusions of recombinant human insulin-like growth factor-I (IGF-I) under euglycaemic clamp conditions. IGF-I increased glomerular filtration rate up to 35% and renal plasma flow up to 100%, this increase being dose dependent with half-maximal stimulation at serum IGF-I concentrations of about 24 pmol ml-1. Renal vascular resistance was reduced up to 50%, filtration fraction decreased up to 30% and urine flow increased up to three fold while arterial blood pressure was unchanged. Renal haemodynamics were affected at serum IGF-I concentrations that did not stimulate total body glucose disposal during euglycaemic clamping. IGF-I seemed to regulate renal function through IGF-I receptors apparently independent of acute changes of glucose metabolism.