Long-acting and selective suppression of growth hormone secretion by somatostatin analogue SMS 201-995 in acromegaly.

In 6 of 7 acromegalic patients a single subcutaneous injection of 50 micrograms of a new octapeptide somatostatin analogue (SMS 201-995) reduced serum growth hormone (GH) from 30 +/- 12 ng/ml to 1.4 +/- 0.4 (mean +/- SEM). Serum GH remained below basal concentration for 9 h. In the remaining patient who had very high basal preprandial serum GH, SMS 201-995 produced a reduction in serum GH of only 20%. Plasma glucose concentrations were increased to the upper limits of the normal range when a high-carbohydrate meal was consumed 2 h after injection. In non-diabetic patients plasma glucose did not exceed 129 mg/dl. The 40% decrease in plasma glucagon, which lasted for 7 h after SMS 201-995 injection, was not statistically significant. No side-effects and no rebound phenomenon were observed. These results suggest that SMS 201-995 may be the first somatostatin analogue suitable for the clinical management of acromegaly.