Endothelin-mediated vasoconstriction in postischemic newborn intestine
| Autor: | Gail M. Schauer, Craig A. Nankervis, Charles E. Miller |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Endothelin Receptor Antagonists
Male medicine.medical_specialty Physiology Eta receptor Swine Ischemia Viper Venoms In Vitro Techniques Muscle Smooth Vascular Oxygen Consumption Piperidines Physiology (medical) Internal medicine Intestine Small medicine Animals Vasoconstrictor Agents Receptor omega-N-Methylarginine Hepatology Endothelin-1 business.industry Gastroenterology Hemodynamics medicine.disease Receptor Endothelin A Endothelin 1 Mesenteric Arteries Oxygen Perfusion Vasodilation Endocrinology Animals Newborn Vasoconstriction Female medicine.symptom business Endothelin receptor Endothelin a Oligopeptides Muscle Contraction |
| Zdroj: | American journal of physiology. Gastrointestinal and liver physiology. 279(4) |
| ISSN: | 0193-1857 |
| Popis: | We previously suggested that the profound, sustained vasoconstriction noted in 3-day-old swine intestine after a moderate episode of ischemia-reperfusion (I/R) reflects the unmasking of underlying constrictor tone consequent to a loss of endothelium-derived nitric oxide (NO). In this study, we sought to determine whether endothelin-1 (ET-1) was the unmasked constrictor and whether selective loss of endothelial ETBreceptors, which mediate NO-based vasodilation, participated in the hemodynamic consequences of I/R in newborn intestine. Studies were performed in innervated, autoperfused intestinal loops in 3- and 35-day-old swine. Selective blockade of ETAreceptors with BQ-610 had no effect on hemodynamics under control conditions; however, when administered before and during I/R, BQ-610 significantly attenuated the post-I/R vasoconstriction and reduction in arteriovenous O2difference in the younger group. In 3-day-old intestine, reduction of intestinal O2uptake to a level similar to that noted after I/R by lowering tissue temperature had no effect on the response to BQ-610 or ET-1, indicating that the change in response to BQ-610 noted after I/R was not simply consequent to the reduction in tissue O2demand. In studies in mesenteric artery rings suspended in myographs, we observed a leftward shift in the dose-response curve for ET-1 after selective blockade of ETBreceptors with BQ-788 in 3- but not 35-day-old swine. Rings exposed to I/R in vivo behaved in a manner similar to control rings treated with BQ-788 or endothelium-denuded non-I/R rings. |
| Databáze: | OpenAIRE |
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