Pro-inflammatory cytokines of rat vasculature in DOCA-salt treatment

The purpose of this study was to ascertain the onset expression of pro-inflammatory cytokines in the aorta and kidney and establish their correlation with the increase in arterial blood pressure in rats subjected to DOCA-salt treatment. Male Sprague-Dawley rats underwent unilateral nephrectomy and received subcutaneous DOCA (20 mg/rat/week) as well as 1% NaCl and 0.2% KCl for drinking for 2 weeks. Blood pressure and expression of pro-inflammatory cytokines in aorta and kidney were studied weekly during the induction of hypertension. The treated rats exhibited a mild elevation of blood pressure at 1 week and a profound increase at 2 weeks. Quantitative RT-PCR demonstrated a 4.9-fold and a 3.6-fold enhancement in the expression of TNF-alpha and IL-6, respectively, in aorta as early as 1 week. The expression of IL-6 and TNF-alpha in the kidney remained almost unchanged at 1 week but mildly increased at 2 weeks DOCA-salt treatment. This study indicates a robust increase in the expression of IL-6 and TNF-alpha in aorta in DOCA-salt treated rats. This enhancement suggests that the activation of pro-inflammatory cytokines may contribute to onset of the elevation of blood pressure in DOCA-salt hypertension model.