Central lead administration inhibits water intake and sodium appetite in rats

Transcription

1 Brazilian Journal of Medical and Biological Research (999) : -8 Lead and central control of water intake and sodium appetite ISSN -89X Short Communication Central lead administration inhibits water intake and sodium appetite in rats E.J. De-Castro-e-Silva, L. Castro, C.P. Luz, H. Ferreira, A.K.S. Lima, F.S.F. Souza, I. Maldonado, D.F. Macêdo, M.G. Ferreira, I.P.V. Bandeira, A.L.M. Amor, F.L.Q. Carvalho, M.A. Rocha Jr. and J.B. Fregoneze Departamento de Fisiologia, Instituto de Ciências da Saúde, and Departamento de Zoologia, Instituto de Biologia, Universidade Federal da Bahia, Salvador, BA, Brasil Correspondence E.J. De-Castro-e-Silva Departamento de Fisiologia Instituto de Ciências da Saúde Universidade Federal da Bahia - Salvador, BA Brasil Fax: emilio@svn.com.br Research supported by CNPq (Nos. /8- and 99/9-8) and by the Bahia State Research Support Financial Agency (CADCT). Received March, 999 Accepted August, 999 Abstract Key words Lead Angiotensin II Water intake Sodium intake Rats Braz J Med Biol Res () 999

2 E.J. De-Castro-e-Silva et al. Braz J Med Biol Res () 999

3 Lead and central control of water intake and sodium appetite Water intake (ml/ g body weight) Salt intake (ml/ g body weight) 9 A C 9 NaAc. nmol/rat % of water intake inhibition % of salt intake inhibition Figure - Cumulative water and salt intake (ml/ g body weight) by rats after a -h period of water deprivation. Absolute values of water intake are presented in panel A. The percentage of lead-induced water intake inhibition (as compared to NaAc-treated rats) is shown in panel B. Absolute values of hypertonic saline intake are presented in panel C. The percentage of lead-induced hypertonic saline intake inhibition (as compared to NaAc-treated rats) is shown in panel D. Absolute values are presented as means ± SEM. P<. compared to the control group receiving NaAc (ANOVA followed by Student-Newman- Keuls test). Open squares (N = ), NaAc. nmol/rat; triangles (N = 8), PbAc. nmol/rat, and closed squares (N = ), PbAc. nmol/rat. PbAc. nmol/rat Pb. nmol Pb. nmol Pb. nmol Pb. nmol B 9 D 9 PbAc. nmol/rat Braz J Med Biol Res () 999

4 E.J. De-Castro-e-Silva et al. Water intake (ml/ g body weight) Salt intake (ml/ g body weight) 9 A C 9 NaAc. nmol/rat % of water intake inhibition % of salt intake inhibition Pb + AII Figure - Cumulative water and salt intake (ml/ g body weight) by rats after third ventricle injections of angiotensin II (AII; 9. nmol/rat). Absolute values of water intake are presented in panel A. The percentage of lead-induced water intake inhibition (as compared to NaAc-treated rats) is shown in panel B. Absolute values of hypertonic saline intake are presented in panel C. The percentage of lead-induced hypertonic saline intake inhibition (as compared to NaAc-treated rats) is shown in panel D. Absolute values are presented as means ± SEM. P<. for the group receiving NaAc + AII compared to the group receiving PbAc + AII (ANOVA followed by Student-Newman-Keuls test). P<. for the group receiving NaAc alone compared to both other groups. Squares (N = 9), NaAc. nmol/rat; lozenges (N = 8), NaAc + AII, and circles (N = ), PbAc. nmol + AII/rat. NaAc. + AII 9. nmol/rat B Pb + AII 9 D 9 PbAc. nmol + AII/rat Braz J Med Biol Res () 999

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