Clinical and experimental pharmacology & physiology
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Clin. Exp. Pharmacol. Physiol. · Nov 1984
Canine nonresponders to alveolar hypoxic vasoconstriction and quantitative restoration of the response by aspirin I-3.
Hypoxic pulmonary vasoconstriction is characterized by considerable variability in rate of response (pulmonary vascular resistance [PVR] as a function of time under hypoxia). To further define this response, forty-five closed chest dogs were anaesthetized (pentobarbitone sodium), intubated, and mechanically ventilated. Constant left lower lobar pulmonary artery flow was maintained through a balloon tipped 14F catheter via an extracorporeal pump at a rate to achieve lobar pulmonary artery pressure (Plobar) equal to main pulmonary artery pressure (PPA) and thereafter held constant. ⋯ The absolute values of PVR reached after plateau for HR and for NR ASA (after ASA) were also not different. Aspirin restored the NR capability to develop pulmonary vasoconstriction in response to alveolar hypoxia. The rate of response and the absolute level of response reached were also restored by aspirin.