Isotonic NaCl intake by cell-dehydrated rats.
Male adult rats that received an intragastric load of 2 ml of 12% NaCl (n=13) ingested both water (4.0+/-0.2 ml/2 h) and 0.9% NaCl (3.7+/-1.0 ml/2 h) when compared with rats that received intragastric load of 2 ml of water (water: 0.1+/-0.1; 0.9% NaCl: 0.5+/-0.3 ml/2 h, n=12) in a two-bottle test. Intragastric sodium load increased plasma sodium concentration and osmolality by 5% and reduced plasma renin activity by half compared to rats that received intragastric load of water. Intravenous infusion of 1.5 ml/10 min of 10% NaCl (n=16) also induced ingestion of water (6.2+/-0.8 ml/2 h) and 0.9% NaCl (2.9+/-0.8 ml/2 h) compared with intravenous infusion of 1.5 ml/10 min of 0.9% NaCl (water: 0.9+/-0.4; 0.9% NaCl: 0.5+/-0.2 ml/2 h, n=14). Therefore, a sodium load that raises natremia and plasma osmolality, and therefore induces cell dehydration, results in both 0.9% NaCl and water ingestion when the rats have a two-bottle choice.
Department of Physiology and Pathology, School of Dentistry, Paulista State University (UNESP), Rua Humaitá, 1680 Centro, 14801-903, Araraquara, São Paulo, Brazil.
Daniela T B
DT
Pereira
Regina C
RC
Vendramini
Richard B
RB
David
Priscila N
PN
Nozaki
José V
JV
Menani
Laurival A
LA
De Luca
D000818:Animals; D001774:Blood Chemical Analysis; D003681:Dehydration / Q000378:metabolism*; D004573:Electrolytes / Q000378:metabolism; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D006400:Hematocrit; D007262:Infusions, Intravenous; D007552:Isotonic Solutions / Q000494:pharmacology*; D008297:Male; D009994:Osmolar Concentration; D011506:Proteins / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012083:Renin / Q000097:blood; D012462:Saline Solution, Hypertonic / Q000494:pharmacology*
D004573:Electrolytes; D007552:Isotonic Solutions; D011506:Proteins; D012462:Saline Solution, Hypertonic; D012083:Renin