Expression of TRP Ion Channels in Cardiac Myocytes

Abstract

The overall goal of this investigation was to determine the extent to which transient receptor potential (TRP) ion channels of the A1 and V1 subtypes are expressed in the murine heart and whether their expression patterns are altered in the setting of diabetes. TRP ion channels are well‐established ion channel receptors found throughout the body and have significant roles in regulation of the cardiovascular system. Surprisingly little is known about coexpression patterns of TRPA1 and TRPV1 in diabetic and healthy cardiac myocytes or the role they play in mediating intracellular events in the heart. Preliminary data from our lab shows for the first time that TRPA1 is expressed at the protein level in isolated mouse cardiac myocytes. Furthermore, we have found that TRPA1 and TRPV1 in cardiac myocytes show significant (P<0.05) dose‐dependent calcium responses when exposed to allyl isothiocyanate (AITC) and capsaicin, respectively. Moreover, the expression levels of these channels in diabetic cardiac myocytes are significantly lower (P<0.05) than those in healthy cardiac myocytes. In conclusion, TRPA1 and TRPV1 ion channels in cardiac myocytes respond to AITC and capsaicin, respectively, and are down‐regulated in diabetic cardiac myocytes.