Referenced in: none

Automatically associated channels: TRP , TRPM , TRPM8

Title: Down-regulation of TRPM8 in pulmonary arteries of pulmonary hypertensive rats.

Authors: Xiao-Ru Liu, Qing Liu, Gai-Ying Chen, Ying Hu, James S K Sham, Mo-Jun Lin

Journal, date & volume: Cell. Physiol. Biochem., 2013 , 31, 892-904

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/23817166

Abstract
Pulmonary hypertension (PH) is characterized by profound vascular remodeling and alterations in Ca(2+) homeostasis in pulmonary arterial smooth muscle cells (PASMCs). Multiple transient receptor potential melastatin-related (TRPM) subtypes have been identified in vascular tissue. However, the changes in the expression and function of TRPM channels in pulmonary hypertension have not been characterized in detail.We examined the expression of TRPM channels and characterized the functions of the altered TRPM channels in two widely used rat models of chronic hypoxia (CH)- and monocrotaline (MCT)-induced PH.CH-exposed and MCT-treated rats developed severe PH and right ventricular hypertrophy, with a significant decrease in TRPM8 mRNA and protein expression in pulmonary arteries (PAs). The downregulation of TRPM8 was associated with significant reduction in menthol-induced cation-influx. Time-profiles showed that TRPM8 down-regulation occurred prior to the increase of right ventricular systolic pressure (RVSP) and right ventricular mass index (RVMI) in CH-exposed rats, but these changes were delayed in MCT-treated rats. The TRPM8 agonist menthol induced vasorelaxation in phenylephrine-precontracted PAs, and the vasorelaxing effects were significantly attenuated in PAs of both PH rat models, consistent with decreased TRPM8 expression.Downregulation of TRPM8 may contribute to the enhanced vasoreactivity in PH.