Effect of cholinergic stimulation of the amygdaloid complex on water and salt intake.
The effect of carbachol (80 nmol/microliters) injection into the amygdaloid nuclear complex (AMG) on sodium appetite and water intake was studied in male Holtzman rats weighing 240-270 g. Twenty-five satiated rats and 38 water-deprived rats were used in the experiment on water intake. In the experiment on sodium intake, 19 rats were injected with atropine+carbachol and 9 rats with hexamethonium+carbachol. After carbachol injection into the AMG, water intake decreased in rats submitted to 30 h of water deprivation (10.28 +/- 1.04 ml/120 min vs 0.69 +/- 0.22 ml/120 min). The decrease in water intake was blocked by prior local injection of atropine (20 nmol/l microliters) (11.66 +/- 1.46 ml/120 min vs 0.69 +/- 0.22 ml/120 min), but not of hexamethonium (30 nmol/1 microliters), into the AMG. In water-deprived animals, carbachol injection into the AMG caused a decrease in sodium chloride intake (6.16 +/- 1.82 ml/h vs 0.88 +/- 0.54 ml/h) which was blocked by previous injection of hexamethonium but not of atropine. These results suggest that the cholinergic system of the AMG plays a role in the control of water and salt intake.
Saad
W A
WA
Departamento de Ciências Fisiológicas, Faculdade de Odontologia, Universidade Estadual Paulista, Araraquara, SP, Brasil.
Bengtson
R M
RM
Menani
J V
JV
Camargo
L A
LA
Renzi
A
A
Silveira
J E
JE
Saad
W A
WA
D000679:Amygdala / Q000187:drug effects* / Q000502:physiology; D000818:Animals; D001285:Atropine / Q000008:administration & dosage; D002217:Carbachol / Q000008:administration & dosage / Q000494:pharmacology*; D004326:Drinking / Q000187:drug effects*; D018738:Hexamethonium; D006584:Hexamethonium Compounds / Q000008:administration & dosage; D007267:Injections; D008297:Male; D010276:Parasympatholytics / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017673:Sodium Chloride, Dietary; D014868:Water Deprivation
D006584:Hexamethonium Compounds; D010276:Parasympatholytics; D017673:Sodium Chloride, Dietary; D018738:Hexamethonium; D001285:Atropine; D002217:Carbachol