Regional pulmonary blood flow during acute pulmonary edema: a PET study.
We used positron emission tomography to evaluate the effects of nitroprusside or prostacyclin (NP/Prost) on regional pulmonary blood flow (rPBF) in 21 dogs after oleic acid- (OA) induced acute pulmonary edema and compared the results with data from 11 dogs given OA only and 5 given meclofenamate after OA. After OA only, a progressive decrease in rPBF occurred in edematous gravity-dependent lung regions, but only in 6 of 11 dogs. In these six dogs, rPBF fell 41 +/- 12% compared with base line or with the other five dogs (3 +/- 19%) (P less than 0.05). In the NP/Prost group, the vasodilators failed to reverse any change in rPBF after OA but did prevent additional derecruitment until the drug infusion was stopped, after which rPBF to the edematous regions decreased further. In contrast, meclofenamate after OA temporally accelerated but did not quantitatively enhance rPBF reduction in edematous lung regions. Thus, in this model, vessels in edematous lung regions remain vasoreactive only until derecruited. We speculate that the mechanism of derecruitment involves an interaction between edema accumulation and vasoconstriction, in which the actual pattern of rPBF after lung injury represents a balance between mechanisms responsible for vascular derecruitment and vasodilation from prostacyclin production.
Schuster
D P
DP
Department of Internal Medicine, Washington University Medical School, St. Louis, Missouri 63110.
Haller
J
J
D000818:Animals; D001834:Body Water / Q000378:metabolism; D004285:Dogs; D011464:Epoprostenol / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D019301:Oleic Acid; D009829:Oleic Acids; D011652:Pulmonary Circulation / Q000187:drug effects / Q000502:physiology*; D011654:Pulmonary Edema / Q000139:chemically induced / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012039:Regional Blood Flow / Q000187:drug effects / Q000502:physiology; D014055:Tomography, Emission-Computed; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology; D014665:Vasodilator Agents / Q000494:pharmacology
D009829:Oleic Acids; D014665:Vasodilator Agents; D009599:Nitroprusside; D019301:Oleic Acid; D011464:Epoprostenol