Heparin ameliorates pulmonary hypertension induced by platelet-activating factor in pigs.
The purpose of this study was to investigate the effects of heparin on the haemodynamic changes which were induced by platelet-activating factor in the pulmonary and systemic circulation in pigs. Mean arterial pressure and mean pulmonary arterial pressure were measured continuously in five anaesthetised juvenile pigs. Bolus doses of platelet-activating factor (0.2-2 microg) were given intravenously to establish a dose response curve. Heparin (300 units/kg) was given intravenously. Thirty minutes later, the same doses of platelet-activating factor were repeated to establish a second dose response curve. Platelet-activating factor caused a dose dependent pulmonary artery hypertension, associated with an initial systemic hypotension followed by systemic hypertension. Heparin effectively reduced the low dose (0.2 microg) platelet-activating factor-induced pulmonary arterial hypertension (p<0.01) but not the higher doses. It had no effect on the platelet-activating factor-induced systemic hypotension or hypertension. The pulmonary and systemic circulation responded differently to platelet-activating factor after giving heparin. While heparin ameliorated the platelet-activating factor-induced pulmonary hypertension, it did not affect the changes in the systemic circulation.
Department of Surgery, University Hospital, Linköping, Sweden.
H
H
Karlsson
F M
FM
Abu-Zidan
S
S
Walther
S
S
Lennquist
D000818:Animals; D000925:Anticoagulants / Q000008:administration & dosage*; D004336:Drug Antagonism; D005260:Female; D006493:Heparin / Q000008:administration & dosage*; D006976:Hypertension, Pulmonary / Q000139:chemically induced / Q000188:drug therapy; D007275:Injections, Intravenous; D008297:Male; D010972:Platelet Activating Factor / Q000633:toxicity*; D013552:Swine
D000925:Anticoagulants; D010972:Platelet Activating Factor; D006493:Heparin