Thyrotropin-releasing hormone-induced contraction of urethral and vaginal muscle.

Pressure studies were carried out in 10 women to determine whether TRH stimulates muscular contractions in the genitourinary system. TRH (500 micrograms) or saline was administered iv as a bolus injection. Whereas saline had no effect, TRH increased intraurethral pressures in all women, vaginal pressure in 7, and bladder pressure in none. These findings suggest that TRH, acting centrally, peripherally, or both, may play a role in initiating muscular contractions in the female genitourinary tract.