CANINE BLADDER BLOOD-FLOW AND OXYGENATION - CHANGES INDUCED BY FILLING, CONTRACTION AND OUTLET OBSTRUCTION

Purpose: To study changes in bladder blood flow and oxygenation associ ated with filling, contraction and outlet obstruction. Materials and M ethods: Intravesical pressure, bladder blood flow, bladder wall oxygen tension, iliac artery blood flow and systemic blood pressure were mea sured simultaneously in anesthetized dogs (N = 18). Results: In the em pty bladder, blood flow and oxygen tension in the bladder base were gr eater than at the dome with and without outlet obstruction. Bladder fi lling caused a significant decrease in bladder wall blood flow and oxy gen tension with and without outlet obstruction. Spontaneous bladder c ontractions resulted in a marked decrease in bladder wall perfusion in the obstructed bladder but not in the unobstructed bladder. Pelvic ne rve stimulation produced strong bladder contractions associated with a significant drop in bladder wall perfusion and bladder oxygenation in both the open and closed bladder neck models. Little change was noted after stimulation of the hypogastric nerve. Conclusions: Bladder dist ention and contraction, especially against a closed bladder neck, indu ce significant ischemia and hypoxia of the bladder wall. These finding s may be important in the pathophysiology of a variety of common clini cal problems.