Gene Expression of Thermosensitive TRP Ion Channels in the Spleen of Normotensive and Hypertensive Rats: Effect of Cold and Peripheral TRPM8 Channel Activation

Arterial hypertension leads to changes in the functioning of various body systems, including the immune one. TRP ion channels are increasingly attracting attention as targets for therapeutic correction of visceral functions. Gene expression of thermosensitive TRP ion channels (TRPM8, TRPA1, TRPV1, TRPV2, TRPV3, TRPV4) was analyzed via quantitative RT-PCR in the immunocompetent organ, spleen, of normotensive and hypertensive rats under normal conditions, as well as during cooling and peripheral cold-sensitive TRPM8 channel activation. The genes of these channels are expressed differentially in the spleen of both rat strains. Gene expression of cold-sensitive TRPM8 and TRPA1 channels is decreased in the spleen of hypertensive rats, which is consistent with our previous data on decreased TRPM8 gene expression in the hypothalamus of the same rat strain. Deep body cooling, as well as menthol-induced activation of peripheral (skin) TRPM8 channels, lead to an increase in the gene expression of TRPA1 and TRPV1 channels in the spleen of hypertensive rats, while unaffecting the expression of these genes in normotensive animals. Given that TRPA1 and TRPV1 channels are involved in inflammatory processes, this may suggest that cold exposure modifies inflammatory reactions in hypertensive animals. The obtained data expand knowledge about the representation of thermosensitive TRP channels in immunocompetent organs and may also indicate a change in the immune status of an organism in arterial hypertension.