The SL-CSF-CN and L-CSF-CN rats were treated with a combination of furosemide (10 mg kg− 1 ml− 1, sc; Xuzhou Ryem Pharma. CP., Ltd., China) + captopril (5 mg kg− 1 ml− 1, sc; Aldrich, USA). Isotonic saline injections were administered to the control group (N = 6 for each group). So there are four groups: L-CSF-CN Treated (lesion of the CSF-CN treated with Furo–Cap), L-CSF-CN Control (lesion of the CSF-CN administered with AZD 6244 saline as control), SL-CSF-CN Treated (sham lesion of the CSF-CN treated with Furo–Cap), and L-CSF-CN Control (lesion of the CSF-CN administered with isotonic saline as control). After keeping the rats without fluids and food for 60 min, we introduced water and 0.3 M NaCl in their cages. The fluid intake in rats was determined for 2 h at time-intervals of 30 min. The sodium preference of these rats was calculated according to the following formula: (volume of 0.3 M NaCl intake) / (volume of 0.3 M NaCl intake + volume of water intake). In this situation, the effect of captopril, an angiotensin (ANG)-converting enzyme inhibitor, increases plasma levels of angiotensin I, which is available in the circumventricular organs of the lamina terminalis, probably the SFO. Here, the local conversion to angiotensin II occurs, leading to the stimulation of water intake and sodium appetite  and . After the termination of the intake test, the rats were killed for histochemical processing.