The effect of somatostatin on plasma insulin and growth hormone levels in basal conditions and after glucagon in normal and acromegalic subjects.

The effect of low-dose somatostatin (2.5 mug/min i.v.) on blood sugar, insulin and GH levels (basal and after i.v. 1 mg glucagon) was studied in 7 normal and 10 acromegalic subjects. No changes in basal values were noted in normal subjects, whereas the insulin response to glucagon was partly inhibited and the glucose response enhanced. Basal blood glucose was likewise unaltered in the acromegalics. There was, however, a significant, though unrelated, fall in both insulin and GH. The insulin response to glucagon was inhibited to a greater degree than in normal subjects. It is clear, therefore, that somatostatin can inhibit the insulin response to glucagon, as well as that to the other stimuli for which data are given in the literature. Acromegalic subjects appear to be more sensitive to inhibition of insulin secretion by somatostatin, though no relation between this and the drug's parallel inhibition of GH secretion can be shown.