Lead (Pb+) and cadmium (Cd2+) inhibit the dipsogenic action of central beta-adrenergic stimulation by isoproterenol
Braz. j. med. biol. res
;
30(3): 419-23, Mar. 1997. tab, graf
Artigo
em Inglês
| LILACS
| ID: lil-191355
ABSTRACT
We have previously demonstrated that acute third ventricle injections of both Pb2+ and Cd2+ impair the dipsogenic response elicited by three different situations dehydration and central cholinergic or angiotensinergic stimulation. beta-Adrenergic activation is part of the multifactorial integrated systems operating in drinking behavior control in the central nervous system. In the present study acute third ventricle injections of Pb2+ (3,30 and 300 pmol/rat) or Cd2+ (0.3, 3 and 30 pmol/rat) blocked the dipsogenic response induced by third ventricle injections of isoproterenol (ISO; 160 nmol/rat) in a dose-dependent manner. Normohydrated animals receiving ISO + NaAc (sodium acetate) or saline (controls) displayed a high water intake after 120 min (ISO + saline = 5.78 ñ O.54 ml/lOO g; ISO + NaAc = 6.00 ñ O.6 ml/lOO g). After the same period,animals receiving ISO but pretreated with PbAc at the highest dose employed (300 pmol/rat) drank O.78 ñ O.23 ml/lOO g while those receiving ISO and pretreated with the highest dose of CdCl(2)(30 pmol/rat) presented a water intake of O.7 ñ O.30 ml/lOO g. Third ventricle injections of CdCl(2) (3 nmol/rat) or PbAc (3 nmol/rat) did not modify food intake in rats deprived of food for 24 h. Thus, general central nervous system depression explaining the antidipsogenic action of the metals can be safely excluded. It is concluded that both Pb2+ and Cd2+ inhibit water intake induced by central beta-adrenergic stimulation.
Texto completo:
DisponíveL
Índice:
LILACS (Américas)
Assunto principal:
Cádmio
/
Ventrículos Cerebrais
/
Antagonistas Adrenérgicos beta
/
Ingestão de Líquidos
/
Isoproterenol
/
Chumbo
Limite:
Animais
Idioma:
Inglês
Revista:
Braz. j. med. biol. res
Assunto da revista:
Biologia
/
Medicina
Ano de publicação:
1997
Tipo de documento:
Artigo
/
Congresso e conferência
/
Documento de projeto
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