Data/hora: 10/06/2024 10:24:54

Provedor de dados: | 56
País: | Brazil
Título: | Effect of electrolytic lesion of the dorsal raphe nucleus on water intake and sodium appetite
Autores: | Olivares,E.L.; Costa-e-Sousa,R.H.; Cavalcante-Lima,H.R.; Lima,H.R.C.; Cedraz-Mercez,P.L.; Reis,L.C.
Data: | 2003-12-01
Ano: | 2003
Palavras-chave: | Sodium appetite; Water intake; Dorsal raphe nucleus; Serotonergic system; Electrolytic lesion; Rats.
Resumo: | The present study determined the effect of an electrolytic lesion of the dorsal raphe nucleus (DRN) on water intake and sodium appetite. Male Wistar rats weighing 290-320 g with a lesion of the DRN (L-DRN), performed two days before experiments and confirmed by histology at the end of the experiments, presented increased sensitivity to the dehydration induced by fluid deprivation. The cumulative water intake of L-DRN rats reached 23.3 ± 1.9 ml (a 79% increase, N = 9) while sham-lesioned rats (SL-DRN) did not exceed 13.0 ± 1.0 ml (N = 11, P &lt; 0.0001) after 5 h. The L-DRN rats treated with isoproterenol (300 µg kg-1 ml-1, sc) exhibited an increase in water intake that persisted throughout the experimental period (L-DRN, 15.7 ± 1.47 ml, N = 9 vs SL-DRN, 9.3 ± 1.8 ml, N = 11, P &lt; 0.05). The L-DRN rats also showed an increased spontaneous sodium appetite during the entire period of assessment. The intake of 0.3 M NaCl after 12, 24, 36 and 72 h by the L-DRN rats was always higher than 20.2 ± 4.45 ml (N = 10), while the intake by SL-DRN was always lower than 2.45 ± 0.86 ml (N = 10, P &lt; 0.00001). Sodium- and water-depleted L-DRN rats also exhibited an increased sodium appetite (13.9 ± 2.0 ml, N = 11) compared to SL-DRN (4.6 ± 0.64 ml, N = 11) after 120 min of observation (P &lt; 0.02). The sodium preference of L-DRN rats in both conditions was always higher than that of SL-DRN rats. These results suggest that electrolytic lesion of the DRN overcomes a tonic inhibitory component of sodium appetite.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003001200013
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X2003001200013
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.36 n.12 2003
Fonte: | info:eu-repo/semantics/openAccess