Background Little information is available regarding the effect of angiotensin Ⅱ (Ang Ⅱ) on the bumetanide-sensitive sodium-potassium-2 chloride cotransporter (NKCC2), the thiazide-sensitive sodium-chloride cotransporter (NCC), and the Cl- channel (CLC)-K2 at both mRNA and protein expression level in Ang Ⅱ-induced hypertensive rats. This study was conducted to investigate the influence of Ang Ⅱ with chronic subpressor infusion on nephron-specific gene expression of NKCC2, NCC and CLC-K2. Results Ang Ⅱ significantly increased blood pressure and up-regulated NKCC2 mRNA and protein expression in the kidney. Expression of CLC-K2 mRNA in the kidney increased 1.6 fold (P