EFFECTS OF INTRAVENOUS THYROTROPIN-RELEASING-HORMONE ON URETHRAL CLOSURE PRESSURE IN FEMALES WITH VOIDING DYSFUNCTION

Objective: The aim of this work was to investigate the effects of intr avenously administered thyrotropin-releasing hormone (TRH) on the uret hral closure pressure in a double-blind, placebo-controlled study. Pat ients and Methods. Sixteen female subjects with either bladder outlet obstruction (BOO) or detrusor underactivity were included in the study . Following randomization, 8 subjects (3 BOO, 5 detrusor underactivity ) received 200 mu g of TRH intravenously, and 8 (4 BOG, 4 detrusor und eractivity) received saline (placebo). Standard fluid fill urethral pr essure profilometry was performed at baseline and 2, 3, 5, 10, 15, and 20 min following TRH injection, measuring functional profile length ( mt), maximum urethral closure pressure (UCP), and closure pressures at the proximal quarter of the FPL (1/4 UCP) and at the distal quarter o f the FPL (3/4 UCP). Results: Significant reductions were found in bot h FPL (p = 0.022) and 3/4 UCP (p = 0.014) in the 'active' group as com pared with the 'placebo' group. Conclusions: TRH administration signif icantly reduces the distal urethral closure pressure. Clarification of the mechanism of action of TRH on the urethra may point the way towar ds new developments in the management of female voiding dysfunction.