This study attempted to evaluate the effect of anion associated with sodium loading on the development of angiotensin II (AII)-induced hypertension in rats. Hypertension was induced by intraperitoneal infusion of AII(125 ng/min) for 12 days via miniosmotic pump (systolic blood pressure on day 12, 143 +/- 3 mm Hg). High dietary intake of sodium chloride significantly augmented the AII-induced hypertension (systolic blood pressure on day 12, 166 +/- 4 mm Hg), but equimolar sodium loading provided as sodium citrate failed to enhance AII hypertension (systolic blood pressure on day 12, 136 +/- 8 mm Hg). Thus, the data suggest that the full expression of salt (NaCl) sensitivity in AII hypertension depends on high dietary intake of both sodium and chloride.