Loss of cerebrovascular Shaker-type K(+) channels: a shared vasodilator defect of genetic and renal hypertensive rats.

ABSTRACT: The cerebral arteries of hypertensive rats are depolarized and highly myogenic, suggesting a loss of K(+) channels in the vascular smooth muscle cells (VSMCs). The present study evaluated whether the dilator function of the prominent Shaker-type voltage-gated K(+) (K(V)1) channels is attenuated in middle cerebral arteries from two rat models of hypertension. Block of K(V)1 channels by correolide (1 micromol/l) or psora-4 (100 nmol/l) reduced the resting diameter of pressurized (80 mmHg) cerebral arteries from normotensive rats by an average of 28 +/- 3% or 26 +/- 3%, respectively. In contrast, arteries from spontaneously hypertensive rats (SHR) and aortic-banded (Ao-B) rats with chronic hypertension showed enhanced Ca(2+)-dependent tone and failed to significantly constrict to correolide o

SUBMITTER: Tobin AA 

PROVIDER: S-EPMC2711739 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature