After the surgery, the rats received intramuscular injections of the analgesic cetoprophen 1% (0.03 ml) and a prophylactic dose of the antibiotic penicillin (30,000 IU). Rats were allowed to recover for 5 days before starting ingestion tests and during this
period they had free access to standard sodium diet, water and 0.3 M NaCl solution. Bilateral injections into the LPBN were made using 5-μl Hamilton syringes connected by polyethylene tubing (PE-10) to 30-gauge injection cannulas. At the time of testing, obturators were removed and the injection cannula (2 mm longer than the guide cannula) was carefully inserted into the guide cannula. For bilateral injections, the Selleck CT99021 first injection was performed on one side, the needle was removed and repositioned on the contra lateral side, and then the second injection made. Therefore injections were made ~ 1 min apart. The injection volume into the LPBN was 0.2 μl on each site. The obturators were replaced after the injections, and the rats were placed back into their cages. Furosemide (FURO) (Sigma-Aldrich, Saint Louis, MO, USA) was dissolved in alkaline saline (pH adjusted Protease Inhibitor Library price to 9.0) and administered sc at the dose of 10 mg/kg of body weight (bw). Captopril (CAP) (Sigma-Aldrich,
Saint Louis, MO, USA), was dissolved in 0.15 M NaCl and administered sc at the dose of 5 mg/kg of bw. Muscimol HBr and losartan potassium (Sigma-Aldrich, Saint Louis, MO, USA) were dissolved in 0.15 M NaCl. The dose of muscimol used in the present study was the same as that used in previous studies that investigated the effects of muscimol injected into the LPBN on water and 0.3 M NaCl intakes (Callera et al., 2005 and De Oliveira et al., 2007). This dose of muscimol produces a long-lasting action (at least for 1 h) when injected into
the LPBN (Callera et al., 2005). The dose of losartan was based on previous studies that have tested PAK6 the effects of central injections of losartan on water and sodium intake and on the pressor response to ANG II (Grippo et al., 2002 and Menani et al., 2004). The dose of losartan used is effective for at least 2 h (Menani et al., 2004). The rats were tested in their home cages. Water and 0.3 M NaCl were provided from burettes with 0.1-ml divisions that were fitted with metal drinking spouts. Food was not available during the tests. Measurements were taken at 30-min intervals for 180 min, starting 10 min after bilateral injections of muscimol (0.5 nmol/0.2 μl) or saline (0.2 μl) into the LPBN. Fluid replete rats that received no pre-treatment (n = 14), were tested for the effects of the combination of losartan and muscimol injections into the LPBN on water and 0.3 M NaCl intake. Losartan (50 μg/0.2 μl) was injected into the LPBN 10 min before muscimol (0.5 nmol/0.2 μl).