Channelpedia

Continuous inhalation of carbon monoxide attenuates hypoxic pulmonary hypertension development presumably through activation of BKCa channels.


Authors: Eric Dubuis, Marie Potier, Rui Wang, Christophe Vandier

Journal, date & volume: Cardiovasc. Res., 2005 Feb 15 , 65, 751-61

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/15664403

Channelpedia reference in: BK

Abstract
OBJECTIVE: We tested the hypothesis that inhalation of a low concentration of exogenous carbon monoxide (CO) attenuates the development of hypoxic pulmonary artery hypertension by activation of large-conductance voltage and Ca(2+)-activated K(+) channels (BK(Ca)). METHODS: The BK(Ca) activity was measured using whole-cell and inside-out patch clamp recordings in Wistar rat pulmonary artery (PA) myocytes. Pulmonary artery pressures were measured in vivo and membrane potentials were recorded in vitro in pressurized resistance arteries. RESULTS: Chronic CO inhalation slightly increases single-channel conductance of BK(Ca) channels and induces a large increase in the sensitivity of BK(Ca) channels to Ca(2+) of PA myocytes from normoxic and chronic hypoxic rats. Consequently, BK(Ca) currents are increased and play a more prominent role in controlling resting membrane potential of PA myocytes. Chronic CO inhalation also reduces hemodynamic changes induced by chronic hypoxia and attenuates hypoxic pulmonary artery hypertension. CONCLUSION: Chronic inhalation of CO attenuates hypoxic pulmonary artery hypertension development presumably through activation of BK(Ca) channels. These results highlight the potential use of CO as a novel avenue for research on the treatment of pulmonary artery hypertension (PAHT) in a similar manner to another gasotransmitter, nitric oxide.