[Response of human urinary bladders to angiotensins: comparison between neurogenic and control bladders]

The response of the human detrusor muscle to angiotensins and the difference in contractility between neurogenic and control bladders were examined. Both angiotensin I and II induced potent contraction of the human detrusor muscle. In Ca-free Krebs' solution the contractile response to angiotensin II was abolished. However, verapamil and indomethacin suppressed it only slightly. Captopril blocked completely the response to angiotensin I, and saralasin inhibited completely the response to both angiotensin I and II. The contraction strength in response to both angiotensin I and II was significantly weaker in the neurogenic bladder than in the control. However, there was no difference in the value of ED50 between the two groups. These findings suggest that angiotensin I is converted to angiotensin II by angiotensin converting enzyme at the detrusor, and that angiotensin II subsequently contracts the detrusor muscle through angiotensin II receptors. The contractility of the neurogenic bladder in response to angiotensin was significantly lower compared to that of the control.