Effect of Various Activation of the Skin TRPA1 Ion Channel on Cardiovascular Systemic Parameters in Hypertensive Rats

Abstract

The effect of different activation of the skin TRPA1 ion channel on the parameters of the cardiovascular system was studied in rats with hereditary stress-induced hypertension while recovery from anesthesia. The activation of the TRPA1 ion channel was performed by application to skin its agonist -allyl isothiocyanate (AITC) in two concentrations 2.5% and 0.5%. The following parameters were measured that characterize the work of the cardiovascular system: Blood pressure (systolic, diastolic, and mean), heart rate, blood flow, and tail blood volume. Stimulation of the TRPA1 ion channel by 2.5% AITC resulted in a diminishing rate of increase in blood pressure and a sharp increase in heart rate while recovering from anesthesia. The mean rate of the arterial pressure rise during recovery from anesthesia was 0.4 ± 0.16 mmHg/min compared to 1.4 ± 0.19 mmHg/ min in control (solvent application), P < 0.01. The heart rate increase was 4.7 ± 0.28 beats/min2 compared to 0.6 ± 0.39 beats/min2 in control (P < 0.001). Parameters of blood flow and the tail blood volume were not significantly changed at 2.5% AITC compared to control. The effect of 0.5% AITC on cardiovascular parameters was another. There was no influence on the recovery of arterial pressure and the heart rate, but there was a pronounced acceleration in the recovery of blood flow and tail blood volume after anesthesia. The mean rate for blood flow recovery at 0.5% AITC application was 0.3 ± 0.07 ml/min2 against 0.1 ± 0.05 ml/min2 in control (P < 0.03) and for the tail blood volume was 1.2 ± 0.33 μl/ min against 0.4 ± 0.14 μl/min in control (P < 0.02). Thus, the influence of the skin TRPA1 ion channel on the parameters of the cardiovascular system depends on the degree of its activation. A low level of the TRPA1 stimulation enhanced the blood flow, while a higher level of the TRPA1 activation discouraged to increase in arterial pressure and significantly increased the heart rate. The results suggest the possibility of the therapeutic use of TRPA1 ion channel activation.