1. Effect of endothelin on bladder contraction: potential role in bladder hyperactivity.
- Author
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Westfall TD, McCafferty GP, Pullen M, Ventre J, Eybye M, Jugus MJ, Brooks SA, Hieble JP, and Brooks DP
- Subjects
- Animals, Benzofurans pharmacology, Carboxylic Acids pharmacology, Dose-Response Relationship, Drug, Hypertension chemically induced, Hypertension complications, Hypertension physiopathology, Indans pharmacology, Infusions, Intravenous, Male, Muscle Contraction drug effects, Propionates pharmacology, Rats, Rats, Inbred SHR, Rats, Inbred WKY, Rats, Sprague-Dawley, Urination drug effects, Urination Disorders chemically induced, Urination Disorders physiopathology, Endothelins pharmacology, Urinary Bladder physiology
- Abstract
In the present study, we demonstrate that the intravenous infusion of endothelin-1 (3 and 10 ng/kg/min) causes a decrease in the mean micturition volume of rats in addition to an increase in mean arterial pressure. These effects are blocked by both the ET(A)/ET(B)-non-selective and the ET(A)-selective endothelin antagonists SB 217242 and SB 247083 respectively (both 30 mg/kg). However, it was also observed that the ET(B)-selective agonist sarafotoxin 6c (3 and 10 ng/kg/min) had similar effects on both mean arterial pressure and micturition volume. Initial experiments indicated that spontaneously hypertensive rats have a much lower mean micturition volume than normal rats. Binding studies comparing the total number and ratio of ET(A)/ET(B) receptors in spontaneously hypertensive, Wister-Kyoto and Sprague-Dawley rats revealed no significant differences in receptor expression. However, the magnitude of the response to endothelin-1 was greater in spontaneously hypertensive versus normal rats., (Copyright 2003 S. Karger AG, Basel)
- Published
- 2003
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