Partial outlet obstruction in rabbits: Duration versus severity

Abstract

Abbreviations & AcronymsObjectives: Oxidative stress is a major etiology of obstructed bladder dysfunction. The major goal of the current study was to correlate the level of oxidative stress with both the severity and duration of obstruction. Methods: A total of 32 New Zealand White rabbits were divided into four equal groups. Groups 1-3 received partial bladder outlet obstructions by standard methods and survived for 4, 8 or 12 weeks. Group 4 received sham surgery at the end of each time period, isolated strips were taken for contractility studies and the balance of the bladder was frozen as muscle and mucosa for quantification of nitrotyrosine and carbonyl-oxidized proteins derivatized into dinitrophenyl. For each duration, the eight rabbits were divided into three severity groups: mild, intermediate or severe decompensation. Results: Contractile responses decreased in proportion to both severity and duration. The level of both oxidative products correlated to a much higher degree with the level of severity than the duration. There were significant decreases in the contractile responses in the mild decompensation group, whereas the level of derivatized into dinitrophenyl and nitrotyrosine of the muscle remained at control levels. This was not the case for the 4 weeks obstructed group. Conclusions: These findings suggest that the etiology for the mechanism of contractile dysfunction is not an oxidative stress.

Effect of severity and duration of bladder outlet obstruction on catalase and superoxide dismutase activity

“…More specifically, in the current studies the enzyme activities of both SOD and catalase were analyzed in bladders that were grouped by severity and duration to see which bore a stronger correlation to the enzyme activities. We have already shown in these rabbits that the concentrations of both DNP and nitrotyrosine have a stronger correlation with severity than duration . These studies on catalase and SOD should also show if the level of oxidative stress is involved in the activities of these two important anti‐oxidant enzymes.…”

“…Although it is true that the longer the rabbits are obstructed, the higher the level of decompensation, previous studies have shown that obstructed rabbits separated by severity of decompensation rather than by duration of obstruction have a much closer correlation between specific cellular and subcellular dysfunctions than if separated by duration of obstruction alone . In part 1 of the present study, we evaluated the level of oxidative damage in rabbits by two different methods: (i) the rabbits were obstructed for 4, 8 and 12 weeks (duration); and (ii) by severity by separating them into mild, intermediate and severe decompensation . The present study clearly showed that the level of oxidative damage (as measured by the free radical oxidative products nitrotyrosine and DNP) was more closely related to severity of decompensation than to the duration of obstruction.…”

Detrusor contraction power parameters (BCI and W max) rise with increasing bladder outlet obstruction grade in men with lower urinary tract symptoms: results from a urodynamic database analysis

“…Microscopic investigations of the bladder wall in these two stages revealed-besides fibroblast hyperplasia and deposition of collagen fibers-smooth muscle cell hypertrophy. Animal studies suggest that bladder emptying in the presence of BOO persists due to increasing detrusor contraction power as a result of structural changes of the bladder wall [2,22]. Additionally, the results of our present study are in line with conclusions from previous studies showing a significant increase of bladder/detrusor wall thickness in symptomatic male patients with BOO [4,5]; therefore, increased detrusor contraction power in patients seems to be generated by increased mass of smooth muscle cells of the bladder wall (detrusor) as well.…”

Effects of Ganoderma Lucidum on Biochemical Dysfunctions of the Rabbit Urinary Bladder using an In-Vitro Model of Ischemia / Reperfusion

“…Oxidative stress (free radical damage) has been found to be a major factor in a number of major human health problems including heart disease [1][2][3], diabetes [4,5], intestinal diseases [6][7][8], liver disease [9], renal disease [10,11] and obstructive bladder dysfunction [12][13][14][15]. In virtually all of these oxidative stress-linked dysfunctions, antioxidants have proven to be very valuable in their treatment [13,[16][17][18][19].…”