Growth hormone response to thyrotropin-releasing hormone in liver cirrhosis: unique alteration in anterior pituitary responsiveness to hypothalamic hormones.

Abstract

Patients with chronic liver diseases were evaluated for: 1) the ability of somatostatin to affect the thyrotropin-releasing hormone (TRH) induced growth hormone (GH) rise; 2) the competence of luteinizing-hormone releasing hormone (LH-RH) to release GH; 3) the non-specific releasing effect of TRH and LH-RH on other anterior pituitary (AP) hormones. In 6 patients, infusion of somatostatin (100 micrograms iv bolus + 375 micrograms i.v. infusion) completely abolished the TRH (400 micrograms i.v.)-induced GH rise; in none of 12 patients, of whom 7 were GH-responders to TRH, did LH-RH (100 micrograms i.v.) cause release of GH; 4) finally, LH-RH (12 patients) did not increase plasma prolactin (PRL) and TRH (7 patients) did not evoke a non-specific release of gonadotropins. It is concluded that: 1) abnormal GH-responsiveness to TRH is the unique alteration in AP responsiveness to hypothalamic hormones present in liver cirrhosis; 2) the mechanism(s) subserving the altered GH response to TRH is different from that underlying the TRH-induced GH rise present in another pathologic state i.e. acromegaly, a condition in which the effect of TRH escapes somatostatin suppression and LH-RH evokes GH and PRL release.