Reparixin, an inhibitor of CXCR1 and CXCR2 receptor activation, attenuates blood pressure and hypertension-related mediators expression in spontaneously hypertensive rats

Abstract

Reparixin, an inhibitor of CXCL8 receptor CXCR1 and CXCR2 activation, has been shown to attenuate inflammatory responses in various injury models. In the present study, the hypertension-related functional roles of reparixin were examined in hypertensive animals. Spontaneously hypertensive rats (SHR) at the age of 18 weeks were administered a subcutaneous injection of reparixin (5 mg/kg) daily for 3 weeks (SHR-R, n=5). Control groups consisted of normal saline-treated SHR (SHR-N, n=5) and normotensive Wistar-Kyoto rats (WKY-N, n=5). Reparixin effectively decreased systolic blood pressure and increased the blood flow. The thoracic aorta wall thickness was significantly decreased in SHR-R compared to SHR-N. Expressions of CXCL8, CCL2, 12-lipoxygenase (LO) and endothelin (ET)-1 were significantly decreased in SHR-R thoracic aorta tissues compared to SHR-N. Furthermore, expression of angiotensin II subtype I receptor (AT(1)R) protein was decreased in SHR-R thoracic aorta tissues compared to SHR-N. In addition, the plasma levels of nitric oxide were slightly elevated in SHR-R compared to the levels in SHR-N. These findings indicate that inhibition of hypertension-related mediators by reparixin results in the reduction of blood pressure in SHR. Therefore, these results suggest that reparixin-mediated blockade of CXCL8 receptor activation attenuates vascular hypertension in SHR.