The role of endothelin-1 in ischemia-reperfusion induced acute inflammation of the bladder in rats.
OBJECTIVE
Endothelin (ET)-1 is causatively involved in ischemia-reperfusion induced acute inflammatory reactions and microcirculatory disturbances in many organs. We investigated the role of endothelin-1 in the microcirculatory consequences of ischemia-reperfusion of the bladder using intravital fluorescence videomicroscopy.


METHODS
Male Sprague-Dawley rats were used in the experiments. The animals were randomly assigned to a sham operated group or to 1 of 2 ischemia-reperfusion groups that underwent 60 minutes of ischemia followed by 30 minutes of bladder reperfusion. In 1 ischemia-reperfusion group the animals were pretreated with BQ 610, a specific ET-A receptor blocker. The bladder was placed on an especially designed stage for intravital fluorescence videomicroscopy measurements. Venular red blood cell velocity, functional capillary density, venular and arteriolar diameter, venular and arteriolar macromolecular leakage, and leukocyte-endothelial cell interactions in postcapillary venules were determined using a computer assisted analyzing system.


RESULTS
Functional capillary density, red blood cell velocity, venular and arteriolar diameter were significantly decreased and macromolecular leakage was significantly enhanced after bladder ischemia-reperfusion. The number of rolling and adherent leukocytes was significantly increased in postcapillary venules. Pretreatment with BQ 610 was effective for attenuating the effects of ischemia-reperfusion induced inflammation but could not completely prevent microcirculatory failure.


CONCLUSIONS
Ischemia-reperfusion induced cystitis leads to significant impairment of the microcirculation and ET-1 is suggested to have an important role in this process. Pretreatment with an ET-A receptor antagonist reduces ischemia-reperfusion related microvascular disturbances in the bladder.
Bajory
Zoltán
Z
Institute for Surgical Research, University of Munich, Germany.
Hutter
Jörg
J
Krombach
Fritz
F
Messmer
Konrad
K
D000208:Acute Disease; D000818:Animals; D003556:Cystitis / Q000209:etiology / Q000503:physiopathology*; D065128:Endothelin Receptor Antagonists; D019332:Endothelin-1 / Q000502:physiology*; D008297:Male; D008833:Microcirculation / Q000473:pathology / Q000502:physiology; D009842:Oligopeptides / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D044022:Receptor, Endothelin A; D015427:Reperfusion Injury / Q000503:physiopathology*; D001743:Urinary Bladder / Q000098:blood supply*
D065128:Endothelin Receptor Antagonists; D019332:Endothelin-1; D009842:Oligopeptides; D044022:Receptor, Endothelin A; C087220:BQ 610