INFLUENCE OF CIRCULATING EPINEPHRINE AND NOREPINEPHRINE ON INSULIN-LIKE-GROWTH-FACTOR BINDING PROTEIN-1 IN HUMANS

The aim of the present study was to investigate the influence of circu lating epinephrine (Epi) and norepinephrine (Norepi) on serum insulin- like growth factor binding protein-1 (IGFBP-1) concentrations. Healthy men received 0.3 nmol(.)kg(.)min Epi iv (n = 6), 0.5 nmol(.)kg(.)min Norepi iv (n = 7), or saline (n = 5) during 30 min. Arterial blood sam ples were obtained before, during, and 120 min after infusion. During the catecholamine infusion arterial Epi and Norepi plasma concentratio ns reached 6.35 +/- 0.53 and 15.65 +/- 2.71 nmol/L, respectively, whic h resulted in significant increases in glucose concentrations. When Ep i was infused, IGFBP-1 increased from 45 +/- 6 mu g/L to 76 +/- 10 mu g/L (P < 0.05) 60 min after the infusion. Epi was also followed by inc reases in insulin, C-peptide, and glucagon. Norepi resulted in a sligh t increase in circulating IGFBP-1 (43 +/- 6 to 54 +/- 8 nmol/L, NS). T he findings suggest that Epi, at plasma concentrations similar to thos e reached during physical stress, stimulates the production of IGFBP-1 in humans.