Variation of blood glucose and serum growth hormone, prolactin and insulin in subjects with insulin-dependent diabetes, after OGTT and pretreatment with 2-Br-alpha-ergocryptine.

In insulin-dependent diabetics high GH values are usually observed. The OGTT does not modify these levels. It was observed that CB 154 (2-Br-alpha ergocryptine) seems capable of lowering GH in acromegalics. We thought it pertinent to check whether or not CB 154 could reduce GH also in diabetics. OGTT was performed in insulin-dependent diabetic patients; 5 days later the same test was repeated after pretreatment with 2.5 mg of CB 154. Serum IRI, GH, hPRL levels and blood glucose values were checked during the test. Significant GH and hPRL variations were not observed after OGTT in the diabetic subjects examined; IRI was always absent, and glycemia followed the model of the diabetic curve. On the contrary, after pretreatment with CB 154, we observed: 1) hPRL reduction; 2) GH increase, sometimes as early as 30 min after OGTT; 3) IRI was never present and blood glucose levels were lower than the values observed with glucose alone. Contrary to what is observed in acromegalics, CB 154 is unable to lower the increased GH levels normally present in insulin-dependent diabetics. After pretreatment with CB 154, OGTT seems to release GH, which is not observed after glucose alone. This can be accounted for only by postulating an antagonism at the hypothalamic level between the adrenergic and serotoninergic pathways of GH stimulation.