The effect of angiotensin converting enzyme inhibition and angiotensin II receptor antagonism on obstructed rat bladder.
OBJECTIVE
Others have demonstrated that inhibition of angiotensin II production partially ameliorates obstructive changes in the neonatal rabbit bladder. We examined the effect of angiotensin II converting enzyme inhibition and receptor antagonism on the obstructed rat bladder.


METHODS
Three groups of animals were investigated. Partial bladder neck obstruction was created in 23 rats by placing a 2-zero silk ligature around the vesicourethral junction. Eight rats were given untreated tap water, 9 were given water supplemented with 50 mg./kg. of the angiotensin-converting enzyme inhibitor captopril and 6 were given water with 30 mg./kg. of the angiotensin II subtype AT1 receptor antagonist losartan potassium. Eight unobstructed rats served as controls. After 2 weeks of partial outlet obstruction the animals were sacrificed and bladders were harvested. Routine histological evaluation and assays for total protein, deoxyribonucleic acid and collagen content were performed.


RESULTS
Histological evaluation revealed that administration of captopril or losartan potassium resulted in a mild decrease in the degree of obstructive bladder changes. Biochemically neither captopril nor losartan potassium caused a significant decrease in the amount of total deoxyribonucleic acid, protein or collagen content per bladder compared to untreated obstructed bladders.


CONCLUSIONS
In contrast to previous studies in neonatal rabbits, neither captopril nor losartan potassium significantly ameliorated the histological or biochemical features of partial bladder outlet obstruction in the rat. Further investigation is necessary into species specific differences to understand better the role that angiotensin II may have in mediating the bladder changes of experimentally induced obstruction.
Palmer
L S
LS
Division of Urology, Children's Memorial Hospital, Chicago, Illinois, USA.
Lee
C
C
Decker
R S
RS
Lang
S
S
Kaplan
W E
WE
Firlit
C F
CF
Cheng
E Y
EY
D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D000818:Animals; D001713:Biphenyl Compounds / Q000627:therapeutic use*; D002216:Captopril / Q000627:therapeutic use*; D007093:Imidazoles / Q000627:therapeutic use*; D019808:Losartan; D051381:Rats; D017207:Rats, Sprague-Dawley; D013777:Tetrazoles / Q000627:therapeutic use*; D001743:Urinary Bladder / Q000473:pathology; D001748:Urinary Bladder Neck Obstruction / Q000188:drug therapy* / Q000473:pathology
D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D001713:Biphenyl Compounds; D007093:Imidazoles; D013777:Tetrazoles; D002216:Captopril; D019808:Losartan