The effect of different preparations of human growth hormone on plasma renin activity in normal males

The effect of acute administration of 2 preparations of growth hormone (hGH) on plasma renin activity (PRA) was studied in normal volunteers. 4 IU of standard, commercially available hGH II, Kabi, Sweden) were injected im into each of four normal subjects, and the PRA was determined in the basal state and at 30, 60, 120, 180, and 240 min after injection. Free fatty acid (FFA) was determined basally and at 15 and 210 min post-injection. The study was repeated on a different day in the same group using highly purified hGH (hGH I, 4 IU) virtually free of arginine-vasopressin. Four other normal subjects received 12 IU standard hGH (hGH II, Kabi, Sweden). There was no significant difference in PRA values with 4 IU of either preparation or with 12 IU of hGH II in any of the groups, although mean PRA was elevated in two of the patients receiving 12 IU hGH II. A rise in FFA occurred in all subjects, indicating the biological activity of hGH preparations. The possible significance of these findings to the renin-angiotensin system found in acromegaly is considered.