Journal of applied physiology
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Previously we found that raising cerebrospinal fluid pressure (PCSF) caused pulmonary vasoconstriction mediated by adrenal catecholamines. To localize the site of this vasoconstriction we used the outflow occlusion technique to divide changes in the pulmonary arteriovenous pressure gradient (Pa-v) into upstream and downstream pressure drops. Experiments were conducted in 10 dogs in which the animal's left lower lung lobe was denervated and perfused at constant flow and outflow pressure with blood pumped from the dog's pulmonary artery. ⋯ Thus, it appears that elevated PCSF caused primarily pulmonary venoconstriction. Similar results were obtained with norepinephrine and epinephrine infusion. This is consistent with previous studies, indicating that adrenal catecholamines are responsible for the increase in Pa-v in response to PCSF in this preparation.