Blood flow of the urinary bladder: Effects of outlet obstruction and correlation with bioenergetic metabolism

Abstract

This study investigated the effects of outlet obstruction on blood flow and high energy phosphates content in the rabbit urinary bladder. Mild bladder outlet obstruction was induced by placing a silicon ring (diameter 7 mm) around the bladder neck of each male New Zealand White rabbit (n = 7). Before and immediately after inducing obstruction, and 2 weeks later, the bladders were emptied and regional blood flow measured using laser Doppler flowmetry (LASERFLO BPM2, Vasamedics Inc., St. Paul, Minnesota). Six different areas of each bladder were measured, and the average blood flow calculated for each rabbit. Then, the animals were sacrificed, the bladder excised, and the tissue content of high energy phosphates determined by high performance liquid chromatography (HPLC). Six normal male New Zealand White rabbits served as controls. The results can be summarized as follows: (1) Before surgery, bladder blood flow was similar in all animals (16.3 ml/min/100 g); positioning the silicon ring around the bladder neck did not affect blood perfusion, two weeks after the induction of outlet obstruction, bladder blood flow was significantly decreased (4.9 ml/min/100 g). (2) There was no significant difference between control and obstructed bladders in NAD, AMP, or ADP content. However, the obstructed bladders contained significantly less phosphocreatine (12.0 vs 21.9 nmol/mg protein) and ATP (4.0 vs. 6.1 nmol/mg protein) than control bladders. In summary, this study showed that urinary bladder blood flow was reduced by outlet obstruction, and the reduction in blood flow was associated with decreased tissue high energy phosphates content.(ABSTRACT TRUNCATED AT 250 WORDS)

Recovery of Microvascular Blood Perfusion and Energy Metabolism of the Obstructed Rabbit Urinary Bladder after Relieving Outlet Obstruction

“…Our earlier study on this speculation showed that chronic bladder outlet obstruction did reduce microvascular blood perfusion of the urinary bladder. Two weeks of outlet obstruction resulted in a decreased microvascular blood perfusion of the bladder wall, which was associated with a decrease in high-energy phosphate content [7]. Again the present study confirmed the same findings.…”

“…Decreased blood perfusion of the urinary bladder by outlet obstruction had been proposed by Elbadawi et al [6]. Indeed, our earlier study on this subject showed that following 2 weeks of outlet obstruction of rabbit urinary bladders, although the bladder mass increased considerably, no concomitant increase in total blood supply happened, resulting in an approximate 70% decrease in microvascular blood perfusion of the bladder wall [7]. However, to definitely confirm the significant role of reduced microvascular blood perfusion in the pathogenesis of bladder dysfunction in outlet obstruction, it is essential to investigate the changes of microvascular blood perfusion not only in the obstructed bladders but also in bladders after relieving the obstruction.…”

Resveratrol supplementation protects against chronic nicotine-induced oxidative damage and organ dysfunction in the rat urogenital system

“…It has been proposed that bladder dysfunction due to oxidant-induced tissue damage is characterized by bladder instability and impairment in detrusor contractility. Although the precise mechanisms of impaired contractile function have not been clarified, it is known that the oxidants alter contractile responses of tissues to various agents (66,67) through the impairment of signal transduction systems (68,69) and antioxidants such as resveratrol may restore function (70).…”

Obstruction-induced alterations within the urinary bladder and their role in the pathophysiology of lower urinary tract symptomatology.

“…41 As a result to hypoxia, obstructed bladders appear hypervascular 22 and partially denervated 42 and exhibit alterations in the mitochondrial structure and function [43][44][45] and the glycogen content. 46,47 Obstruction also induces protein oxidation in the detrusor smooth muscle; 48 lactic acid, due to the anaerobic metabolism, accumulates causing contractile dysfunction.…”