Abstract

In recent years salmon calcitonin (sCT) has been shown to inhibit spontaneous growth hormone (GH) secretion and the GH response to arginine, to insulin-induced hypoglycaemia and to GHRH (Growth Hormone Releasing Hormone). The aim of the present study was to evaluate if sCT is able to inhibit the GH response to a physical exercise, which is a physiological stimulus for GH secretion. Six untrained men were evaluated. Physical stress was produced by means a motor-driven treadmill. Two progressive exercise-tests were performed for each subject at about 85% of their VO2max (after placebo and after sCT-Sandoz: 100 UI i.m.). Blood samples were drawn before drug administration (-60, -30, -15 min). All samples were analyzed in duplicate for GH by radioimmunoassay (RIA). No effects of sCT on GH secretion in basal condition were seen. In placebo treated group GH rised from basal values of 1.2+/-0.75 ng/ml to a maximum level of 7.1+/-2.38 ng/ml fifteen minutes after stopped exercise (p<0.05 vs B). In sCT treated group GH didn't increase after exercise. Significant differences were seen between the two different experimental conditions (p<0.05) at +15 min and +30 min between sCT-GH and placebo-GH. In conclusion our results show that sCT inhibits exercise-induced GH secretion in males. Further studies are necessary to verifiy the exact mechanisms of the observed inhibition and the possible clinical application. Verf.-Referat