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.