Involvement of barium-sensitive K~+ channels in endothelium-dependent vasodilation produced by hypercapnia in rat mesenteric vascular beds

摘要

We examined the vasodilatory effect of hypercapnia in the rat isolated mesenteric vascular bed. The preparation was perfused constantly (5 ml min~-1 with oxygenated Krebs-Ringer solution, and the perfusion pressure was measured. In order to keep the extracellular pH(pHe) constant (around 7.35) against a change in CO_2 adequate amounts of NaHCO_3 were added to Krebs-Ringer solution. In the endothelium intact preparations, an increase in CO_2 from 2.5/100 to 10/100 in increments of 2.5/100 Decreased the 10μM phenylephrine(PE)-produced increase in the perfusion pressure in a concentration- Dependent manner.