In:
American Journal of Physiology-Lung Cellular and Molecular Physiology, American Physiological Society, Vol. 287, No. 4 ( 2004-10), p. L665-L672
Abstract:
Recent evidence suggests that Rho/Rho kinase signaling plays an important role in the sustained vasoconstriction induced by many agonists and is involved in the pathogenesis of systemic vascular diseases. However, little is known about its role in increased vascular tone in hypoxic pulmonary hypertension (PH). The purpose of this study was to examine whether Rho/Rho kinase-mediated Ca 2+ sensitization contributed to sustained vasoconstriction and increased vasoreactivity in hypoxic PH in rats. Acute intravenous administration of Y-27632, a Rho kinase inhibitor, nearly normalized the high pulmonary arterial blood pressure and total pulmonary resistance in chronically hypoxic rats. In contrast to nifedipine, Y-27632 also markedly decreased elevated basal vascular tone in hypertensive blood-perfused lungs and isolated pulmonary arteries. Y-27632 and another Rho kinase inhibitor, HA-1077, completely reversed nitro-l-arginine-induced vasoconstriction in physiological salt solution-perfused hypertensive lungs, whereas inhibitors of myosin light chain kinase (ML-9), protein kinase C (GF-109203X), phosphatidylinositol 3-kinase (LY-294002), and tyrosine kinase (tyrphostin A23) caused only partial or no reversal of the vasoconstriction. Vasoconstrictor responses to KCl were augmented in hypertensive physiological salt solution-perfused lungs and pulmonary arteries, and the augmentation was eliminated by Y-27632. These results suggest that Rho/Rho kinase-mediated Ca 2+ sensitization plays a central role in mediating sustained vasoconstriction and increased vasoreactivity in hypoxic PH.
Type of Medium:
Online Resource
ISSN:
1040-0605
,
1522-1504
DOI:
10.1152/ajplung.00050.2003
Language:
English
Publisher:
American Physiological Society
Publication Date:
2004
detail.hit.zdb_id:
1477300-4
SSG:
12
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