Comparison of responses to sarafotoxins 6a and 6c in pulmonary and systemic vascular beds
| Autor: | P. J. Kadowitz, J. A. Bellan, T. R. Higuera, R. K. Minkes |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Male
Pulmonary Circulation medicine.medical_specialty Time Factors Physiology Hemodynamics Blood Pressure Vasodilation Hexamethonium Compounds Viper Venoms Pulmonary Artery Hexamethonium Physiology (medical) Internal medicine Glyburide medicine Animals Vasoconstrictor Agents Splanchnic Circulation Cardiac Output Meclofenamic Acid Dose-Response Relationship Drug business.industry Endothelins Isoproterenol Central venous pressure Hindlimb Kinetics Blood pressure medicine.anatomical_structure Regional Blood Flow Anesthesia Circulatory system Cats Cardiology Vascular resistance Female Vascular Resistance medicine.symptom Cardiology and Cardiovascular Medicine Endothelin receptor business Vasoconstriction |
| Zdroj: | American Journal of Physiology-Heart and Circulatory Physiology. 262:H852-H861 |
| ISSN: | 1522-1539 0363-6135 |
| Popis: | Cardiovascular and pulmonary responses to sarafotoxin (S) 6a and S6c were investigated in the anesthetized cat. Intravenous injections of the peptides in doses of 0.1-1.0 nmol/kg caused decreases or biphasic changes in arterial pressure (AP) and increases in central venous pressure, pulmonary arterial pressure (PAP), and cardiac output (CO). Secondary decreases in CO were observed in response to higher doses, and biphasic changes in systemic (SVR) and pulmonary (PVR) vascular resistances were observed. Under constant-flow conditions, the peptides only increased pulmonary lobar arterial perfusion pressure and lobar vascular resistance. AP responses to S6a, S6c, endothelin (ET)-1, ET-2, vasoactive intestinal contractor (VIC), and Lys7-ET-1 were similar, whereas AP responses to S6b and ET-3 were similar. S6a, S6b, S6c, ET-1, ET-2, ET-3, VIC, Lys7-ET-1, and big ET-1 increased PAP. S6a and S6c increased distal aortic and superior mesenteric arterial (SMA) blood flow and caused biphasic changes at the highest doses. Under constant-flow conditions, S6a and S6c produced dose-dependent biphasic changes in hindquarters perfusion pressure. Changes in SVR and PVR in response to the peptide were not affected by hexamethonium, glyburide, or meclofenamate, indicating that responses are independent of autonomic reflexes, activation of ATP-regulated K+ channels, or release of cyclooxygenase products. In contrast, N-nitro-L-arginine methyl ester decreased hindquarters vasodilator response to S6a and S6c. The present data show that S6a and S6c produce both vasodilation and vasoconstriction in the systemic vascular bed and increase lobar vascular resistance and that hindquarters vasodilator responses are mediated, in part, by the release of endothelium-derived relaxing factor. |
| Databáze: | OpenAIRE |
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