Hemodynamic responses to sarafotoxin 6 peptides.
Hemodynamic responses to sarafotoxin (SFTX6) peptides and endothelin-1 (ET-1) were compared in the anesthetized cat. SFTX6a and ET-1 at a dose of 0.3 nmol/kg i.v. produced a biphasic change in arterial pressure characterized by an initial decrease followed by a secondary increase in pressure. In contrast, similar doses of SFTX6b and SFTX6c produced mainly decreases in arterial pressure. Each peptide produced increases in central venous pressure, pulmonary arterial pressure, left atrial pressure, and cardiac output. Secondary decreases in cardiac output could be observed in response to SFTX6a and ET-1. SFTX6a and ET-1 produced biphasic changes, whereas SFTX6b and SFTX6c produced only decreases in systemic vascular resistance. In contrast, each peptide produced biphasic changes in pulmonary vascular resistance. The initial fall in pulmonary vascular resistance may be passively related to an increase in pulmonary blood flow because it occurs at a time when cardiac output is increased and no initial fall in pulmonary arterial pressure is observed. The present data show that the SFTX6 peptides can produce different patterns of responses in the systemic vascular bed of the cat, whereas responses in the pulmonary vascular bed are similar.
Minkes
R K
RK
Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA 70112.
Kadowitz
P J
PJ
D000758:Anesthesia; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002415:Cats; D016232:Endothelins / Q000494:pharmacology*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D008297:Male; D010455:Peptides / Q000494:pharmacology; D011652:Pulmonary Circulation / Q000187:drug effects; D012039:Regional Blood Flow / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects; D014757:Viper Venoms / Q000494:pharmacology*
D016232:Endothelins; D010455:Peptides; D014757:Viper Venoms; C057354:sarafotoxins s6