Beschreibung:
<jats:p>We have examined the effects of Y‐27632, a specific inhibitor of Rho‐activated kinases (ROCK I and ROCK II) upon sustained hypoxic pulmonary vasoconstriction (HPV) in both rat isolated small intrapulmonary arteries (IPA) and perfused rat lungs <jats:italic>in situ</jats:italic>. Y‐27632 (100 n<jats:sc>M</jats:sc>–3 μ<jats:sc>M</jats:sc>) was found to cause a concentration‐dependent inhibition of acute sustained HPV in rat IPA. Application of Y‐27632 (10–600 n<jats:sc>M</jats:sc>) in perfused rat lungs caused no change in basal perfusion pressure, but was found to inhibit HPV in a concentration‐dependent manner, resulting in complete ablation of the pressor response to hypoxia at a concentration of 600 n<jats:sc>M</jats:sc>. Furthermore, addition of Y‐27632 at any point during hypoxia caused a reversal of HPV in perfused rat lungs. These results suggest that activation of Rho‐associated kinase may be a pivotal step in the generation of sustained HPV.</jats:p><jats:p><jats:italic>British Journal of Pharmacology</jats:italic> (2000) <jats:bold>131</jats:bold>, 5–9; doi:<jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" xlink:href="10.1038/sj.bjp.0703537">10.1038/sj.bjp.0703537</jats:ext-link></jats:p>