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| De-Castro-e-Silva,E.J.; Castro,L.; Luz,C.P.; Ferreira,H.; Lima,A.K.S.; Souza,F.S.F.; Maldonado,I.; Macêdo,D.F.; Ferreira,M.G.; Bandeira,I.P.V.; Amor,A.L.M.; Carvalho,F.L.Q.; Rocha Jr.,M.A.; Fregoneze,J.B.. |
| We have demonstrated that acute third ventricle injections of lead acetate (PbAc) exert a powerful antidipsogenic effect and induce a significant increase in renal sodium excretion. In the present study we confirm the antidipsogenic effect of lead and demonstrate that central administration of this metal, in minute amounts, significantly reduces salt intake both during dehydration and after central angiotensinergic stimulation. Adult male Wistar rats had the third ventricle cannulated seven days before the experiments. During this period they had free access to distilled water and hypertonic saline solution (1.5%). After a 24-h period of fluid deprivation, experimental animals received third ventricle injections of PbAc (0.3, N = 8 and 3.0 nmol/rat, N =... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Lead; Angiotensin II; Water intake; Sodium intake; Rats. |
| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999001000011 |
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| De-Castro-e-Silva,E.; Luz,C.P.; Sarmento,C.; Nascimento,T.; Gonzalez,V.; Marinho,C.A.; Castro,L.; Oliveira,P.; Santana Jr.,P.; De-Oliveira,I.R.; De-Paula,S.; Lima,A.K.S.; Fregoneze,J.B.. |
| We have previously demonstrated that acute third ventricle injections of both lead and cadmium prevent the dipsogenic response elicited by dehydration or by central injections of dipsogenic agents such as angiotensin II, carbachol and isoproterenol in rats. We have also shown that the antidipsogenic action of cadmium may be due, at least in part, to activation of thirst-inhibitory central serotonergic pathways. In the present paper we show that in Wistar male rats the antidipsogenic effect of both lead acetate (3.0 nmol/rat) and cadmium chloride (3.0 nmol/rat) may be partially dependent on the activation of brain opiatergic pathways since central injections of naloxone (82.5 nmol/rat), a non-selective opioid antagonist, blunt the thirst-inhibiting effect... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Cadmium; Lead; Water intake; Opioids; Rats. |
| Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000600013 |
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| Fregoneze,J.B.; Luz,C.P.; Castro,L.; Oliveira,P.; Lima,A.K.S.; Souza,F.; Maldonado,I.; Macêdo,D.F.; Ferreira,M.G.; Bandeira,I.P.V.; Rocha Jr.,M.A.; Carvalho,F.L.Q.; De-Castro-e-Silva,E.. |
| We have demonstrated that central administration of zinc in minute amounts induces a significant antidipsogenic action in dehydrated rats as well as in rats under central cholinergic and angiotensinergic stimulation. Here we show that acute third ventricle injections of zinc also block water intake induced by central ß-adrenergic stimulation in Wistar rats (190-250 g). Central inhibition of opioid pathways by naloxone reverses the zinc-induced antidipsogenic effect in dehydrated rats. After 120 min, rats receiving third ventricle injections of isoproterenol (160 nmol/rat) exhibited a significant increase in water intake (5.78 ± 0.54 ml/100 g body weight) compared to saline-treated controls (0.15 ± 0.07 ml/100 g body weight). Pretreatment with zinc (3.0,... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Zinc; Isoproterenol; Opioids; Thirst; Naloxone; Rats. |
| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999001000007 |
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