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Updated: Sep 2, 2026

Videomorphometric Analysis of Hypoxic Pulmonary Vasoconstriction of Intra-pulmonary Arteries Using Murine Precision Cut Lung Slices
Published on: January 14, 2014
Pulmonary vasodilator action of tolazoline
Abstract:
The pulmonary vasodilator action of tolazoline in newborn lambs was shown to be mediated via histamine receptors. Maximal changes in pulmonary vascular resistance, deltaPVR, were calculated as percents of the base line value, %deltaPVR. The mean %deltaPVR after tolazoline, 1 mg/kg, was -25 +/- 4% for eight lambs. Four lambs then received the histamine H1 receptor antagonist, diphenhydramine, and the mean %deltaPVR due to tolazoline was -12 +/- 4%. Four lambs received the H2 receptor antagonist, metiamide, and the mean %delta PVR due to tolazoline was -18 +/- 5%. After both H1 and H2 antagonists, the mean %deltaPVR due to tolazoline was +6 +/- 8%. Therefore, both histamine H1 and H2 receptors were involved in the vasodilator response to tolazoline.
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