Central alpha-adrenergic agonists and need-induced 3% NaCl and water intake.
In the present study, noradrenaline (NOR, alpha-non-specific adrenergic agonist), clonidine (CLO, alpha 2), phenylephrine (PHE, alpha 1) or isoproterenol (ISO, beta-agonist) was injected in the medial septal area (MSA) of water-deprived, sodium-deplete or food-deprived rats. NOR (80, 160 nmol) inhibited the intake of 3% NaCl, water deprivation-induced and meal-associated water intake. Food deprivation-induced food intake and 10% sucrose intake were not altered by NOR. CLO (10, 20, 30, 40 nmol) inhibited (80-100% inhibition compared to control during 60 min) the intake of 3% NaCl, water deprivation-induced and meal-associated water intake. CLO had a weaker inhibition on food and 10% sucrose intake (30-50% less than the control during 60 and 15 min, respectively). PHE (160 nmol) inhibited 3% NaCl intake and 10% sucrose intake (30% less than the control for 15-30 min). ISO (160 nmol) did not alter water or 3% NaCl intake. NOR induced an increase, CLO and ISO induced a decrease, and PHE no alteration in mean arterial pressure. NOR did not alter water or 3% NaCl intake when injected unilaterally into the caudate nucleus. The results suggest that NOR injected in the MSA acts on alpha 2-adrenergic receptors inducing a specific inhibition of 3% NaCl and water intake.
Yada
M M
MM
Department of Physiological Sciences, School of Dentistry, Paulista State University, Araraquara, São Paulo, Brazil.
de Paula
P M
PM
Menani
J V
JV
de Luca Júnior
L A
LA
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003000:Clonidine / Q000494:pharmacology*; D004039:Diet, Sodium-Restricted; D004327:Drinking Behavior / Q000187:drug effects*; D004353:Drug Evaluation, Preclinical; D005247:Feeding Behavior / Q000187:drug effects; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D010656:Phenylephrine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012965:Sodium Chloride / Q000008:administration & dosage*; D013395:Sucrose / Q000008:administration & dosage; D014868:Water Deprivation
D000316:Adrenergic alpha-Agonists; D000318:Adrenergic beta-Agonists; D010656:Phenylephrine; D012965:Sodium Chloride; D013395:Sucrose; D007545:Isoproterenol; D003000:Clonidine