INFLUENCE OF ERYTHROPOIETIN ON PARADOXICAL RESPONSES OF GROWTH-HORMONE TO THYROTROPIN-RELEASING-HORMONE IN UREMIC PATIENTS

Several alterations in growth hormone (GH) secretion have been reporte d in patients with chronic renal failure. The aim of the present repor t has been to assess the affect of acutely administered recombinant hu man erythropoietin (rHuEPO) infusion on GH responses to thyrotropin-re leasing hormone (TRH) in uremic patients. Twelve male patients (mean a ge 46.2 years, range 24 to 69) were studied. Seven of them were on con tinuous ambulatory peritoneal dialysis (CAPD), two on chronic hemodial ysis (HD) and two in pre-dialysis (PreD). None had been treated before with rHuEPO. Each patient was tested with TRH (400 mu g i.v. in bolus ), and with TRH plus rHuEPO (40 U/kg in constant infusion for 30 min) on different days. TRH administration provoked a paradoxical response of GH (peak > 5 mu g/liter) in nine (5 CAPD, 2 HD, 2 PreD) out of 12 p atients. In this group of patients with anomalous GH responses, rHuEPO infusion produced an abolishment of the paradoxical responses (GH pea k < 5 mu g/liter) in eight patients and a marked decrease in a further one. On the contrary, in patients with no paradoxical GH response, st imulation with TRH plus rHuEPO did not induce any change in GH release compared with that observed after TRH alone. rHuEPO had no effect on TRH-induced thyrotropin release. These results suggest that the parado xical GH response to TRH in patients with chronic renal failure is blo cked by rHuEPO administration. This rHuEPO action might be mediated by an increased release of somatostatin or an inhibited GH-releasing hor mone secretion.