Effect of somatostatin on abnormal growth hormone and prolactin secretion in patients with the carcinoid syndrome.

Growth hormone (GH) secretion has been studied in two patients with the carcinoid syndrome during glucose loading and growth hormone-release inhibiting hormone (GHRIH, somatostatin) infusion. Both patients had elevated fasting GH levels which were not suppressed by glucose; GH levels fell rapidly during GHRIH infusion. One patient also had hyperprolactinaemia with galactorrhoea and the prolactin (PRL) levels were unaltered by GHRIH. The association between carcinoid tumours and abnormalities of GH and PRL secretion is discussed.