Effect of parathyroidectomy on thyrotropic and lactotropic function in patients with renal osteopathy.

To test the effect of parathyroidectomy on thyrotropic and lactotropic function, a thyrotropin-releasing hormone (TRH) test was performed before and between the 2nd and 3rd month after operation in 13 haemodialysed patients with secondary hyperparathyroidism. The thyrotropin response to TRH was higher in the postoperative period as compared with the values before the operation (p < 0.01). The prolactin response to TRH did not differ from the values before the operation. No correlations between thyrotropin response and serum parathyroid hormone (PTH), ionised calcium and haemoglobin or haematocrit were found. The lower sensitivity of the thyrotropic system to TRH in patients with renal osteopathy is not dependent on serum PTH or calcium.