EDHF-mediated vasodilation involves different mechanisms in normotensive and hypertensive rat lungs
| Autor: | Masahiko Oka, Ivan F. McMurtry, Yoshiteru Morio, Ethan P. Carter |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Male
Endothelium-derived hyperpolarizing factor medicine.medical_specialty Endothelium Physiology Hypertension Pulmonary Blood Pressure Vasodilation Rats Sprague-Dawley Biological Factors Cytochrome P-450 Enzyme System Physiology (medical) Internal medicine Animals Medicine Enzyme Inhibitors Hypoxia Hypertrophy Right Ventricular business.industry Gap junction Gap Junctions Hypoxia (medical) medicine.disease Pulmonary hypertension Rats medicine.anatomical_structure Endocrinology Vasoconstriction Circulatory system cardiovascular system Thapsigargin medicine.symptom Cardiology and Cardiovascular Medicine business Blood vessel |
| Zdroj: | American Journal of Physiology-Heart and Circulatory Physiology. 284:H1762-H1770 |
| ISSN: | 1522-1539 0363-6135 |
| DOI: | 10.1152/ajpheart.00831.2002 |
| Popis: | The role of endothelium-derived hyperpolarizing factor (EDHF) in regulating the pulmonary circulation and the participation of cytochrome P-450 (CYP450) activity and gap junction intercellular communication in EDHF-mediated pulmonary vasodilation are unclear. We tested whether tonic EDHF activity regulated pulmonary vascular tone and examined the mechanism of EDHF-mediated pulmonary vasodilation induced by thapsigargin in salt solution-perfused normotensive and hypoxia-induced hypertensive rat lungs. After blockade of both cyclooxygenase and nitric oxide synthase, inhibition of EDHF with charybdotoxin plus apamin did not affect either normotensive or hypertensive vascular tone or acute hypoxic vasoconstriction but abolished thapsigargin vasodilation in both groups of lungs. The CYP450 inhibitors 7-ethoxyresorufin and sulfaphenazole and the gap junction inhibitor palmitoleic acid, but not 18α-glycyrrhetinic acid, inhibited thapsigargin vasodilation in normotensive lungs. None of these agents inhibited the vasodilation in hypertensive lungs. Thus tonic EDHF activity does not regulate either normotensive or hypertensive pulmonary vascular tone or acute hypoxic vasoconstriction. Whereas thapsigargin-induced EDHF-mediated vasodilation in normotensive rat lungs involves CYP450 activity and might act through gap junctions, the mechanism of vasodilation is apparently different in hypertensive lungs. |
| Databáze: | OpenAIRE |
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