[Pancreatic exocrine and endocrine functions stimulated with secretin and thyrotropin-releasing hormone in patients with hyperparathyroidism].

This study was designed to investigate pancreatic exocrine and endocrine secretion stimulated with secretin and thyrotropin-releasing hormone (TRH) in hyperparathyroidism. Pancreatic exocrine secretion during 30 min stimulated by constant secretin infusion of 1U/kg/hour was significantly increased in patients with secondary hyperparathyroidism compared with controls and patients with primary hyperparathyroidism. Intravenous administration of TRH at a dose of 20 micrograms/kg/hour, superimposed on secretin, produced a significant decrease of pancreatic exocrine secretion in both primary and secondary hyperparathyroidism but not in control. Serum insulin, glucagon and secretin levels were significantly higher in the subjects of both primary and secondary hyperparathyroidism than those of controls. Serum glucagon and secretin levels were significantly higher in secondary hyperparathyroidism than primary hyperparathyroidism. The pancreatic endocrine secretion was not influenced by TRH administration. Pancreatic exocrine secretion was not changed by parathyroidectomy in patients with primary hyperparathyroidism. As for endocrine secretion, however, only serum secretin level decreased to the level before parathyroidectomy. In this study, it was speculated that the increase of pancreatic secretion in secondary hyperparathyroidism may be due to hypersecretinemia, and the decrease of exocrine secretion by TRH in primary and secondary hyperparathyroidism may be resulted from the direct effect of TRH on the pancreatic acinar cells.