The reaction of adenohypophysis hormones in primary hyperparathyroidism and after surgical treatment.

The anterior pituitary hormone serum levels of 13 patients of both sexes were examined for basal secretion and response to TRH-GnRH stimulus before and after parathyroidectomy. The patients were suffering from hyperparathyroidism of parathyroid adenoma origin. After the operation, the previously high serum calcium and low serum phosphate levels decreased (P < 0.001). The serum parathyroid hormone (PTH) concentration, too, decreased significantly. After surgery, the basal and stimulated secretion of thyrotropin (TSH) showed a significant increase (P < 0.02 and P < 0.05, respectively). Significantly higher prolactin (PRL) levels were measured after surgery in those patients whose PRL levels were normal both before and after the operation. No significant change was observed in patients with hyperprolactinaemia. After surgery an increased spontaneous growth hormone (GH) secretion was found, while the basal luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretions remained unchanged. In postmenopausal women the stimulated FSH secretion decreased (P < 0.05), while the decrease of the stimulated LH secretion was not significant. The results suggest that extracellular calcium may modify the secretion of certain adenohypophysis hormones and their stimulus-induced response.