FURO/CAP: a protocol for sodium intake sensitization.
We investigated if a history of FURO/CAP, a protocol that increases brain angiotensin II (ANG II), sensitizes or enhances sodium intake. A subcutaneous injection of the diuretic furosemide (FURO, 10mg/kg) was combined with a converting enzyme inhibitor captopril (CAP, 5mg/kg) to induce a short latency stimulated sodium (0.3M NaCl) and water intake in a 2h FURO/CAP test. Repeated injections of only FURO/CAP, separated by one-week interval, enhanced stimulated and spontaneous (daily) sodium intake. Stimulated fluid intake was completely suppressed when FURO/CAP was combined with two intraperitoneal injections of the ANG II type-1 receptor antagonist losartan (10, 20, or 40 mg/kg each) given within 1h prior to the FURO/CAP test. Losartan reduced by only 35% the FURO/CAP-induced natriuresis. A history of FURO/CAP, FURO/CAP+losartan (all doses), or vehicle produced similar stimulated fluid intake when all animals received only FURO/CAP in the third final FURO/CAP test. However, a history of vehicle or FURO/CAP+losartan 10mg/kg precluded the enhancement in spontaneous sodium intake after the third final FURO/CAP. The FURO/CAP combined with losartan (all doses) also precluded the spontaneous sodium intake enhancement in the weeks that preceded the third final FURO/CAP test. A history of only FURO/CAP, but not vehicle, also enhanced water deprivation-induced sodium appetite. The results suggest that a history of FURO/CAP enhances stimulated and spontaneous sodium intake, as well as water deprivation-induced sodium appetite, and reinforce the role of ANG II as a peptide that mediates long-term effects on behavior.
Pereira
Daniela T B
DT
Department of Physiology and Pathology, School of Dentistry, Rua Humaitá, 1680, São Paulo State University - UNESP, 14801-903, Araraquara, São Paulo, Brazil.
Menani
José V
JV
De Luca
Laurival A
LA
D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D001066:Appetite / Q000187:drug effects*; D001522:Behavior, Animal / Q000187:drug effects; D002216:Captopril / Q000494:pharmacology*; D004232:Diuretics / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004326:Drinking / Q000187:drug effects; D004338:Drug Combinations; D005665:Furosemide / Q000494:pharmacology*; D019808:Losartan / Q000494:pharmacology; D008297:Male; D051381:Rats; D012965:Sodium Chloride / Q000378:metabolism*; D014868:Water Deprivation / Q000502:physiology
D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors; D004232:Diuretics; D004338:Drug Combinations; D012965:Sodium Chloride; D005665:Furosemide; D002216:Captopril; D019808:Losartan