Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/31261
Type: Artigo de periódico
Title: Consequences of cerebroventricular insulin injection on renal sodium handling in rats: effect of inhibition of central nitric oxide synthase
Author: Oliveira, P.C.
Michelotto, J.B.
Zapparoli, A.
Boer, P.A.
Gontijo, J.A.R.
Abstract: In the present study, we investigated the effects of acute intracerebroventricular (icv) insulin administration on central mechanisms regulating urinary sodium excretion in simultaneously centrally NG-nitro-L-arginine methylester (L-NAME)-injected unanesthetized rats. Male Wistar-Hannover rats were randomly assigned to one of five groups: a) icv 0.15 M NaCl-injected rats (control, N = 10), b) icv dose-response (1.26, 12.6 and 126 ng/3 µL) insulin-injected rats (N = 10), c) rats icv injected with 60 µg L-NAME in combination with NaCl (N = 10) or d) with insulin (N = 10), and e) subcutaneously insulin-injected rats (N = 5). Centrally administered insulin produced an increase in urinary output of sodium (NaCl: 855.6 ± 85.1 Δ%/min; 126 ng insulin: 2055 ± 310.6 Δ%/min; P = 0.005) and potassium (NaCl: 460.4 ± 100 Δ%/min; 126 ng insulin: 669.2 ± 60.8 Δ%/min; P = 0.025). The urinary sodium excretion response to icv 126 ng insulin microinjection was significantly attenuated by combined administration of L-NAME (126 ng insulin: 1935 ± 258.3 Δ%/min; L-NAME + 126 ng insulin: 582.3 ± 69.6 Δ%/min; P = 0.01). Insulin-induced natriuresis occurred by increasing post-proximal sodium excretion, despite an unchanged glomerular filtration rate. Although the rationale for decreased urinary sodium excretion induced by combined icv L-NAME and insulin administration is unknown, it is tempting to suggest that perhaps one of the efferent signals triggered by insulin in the CNS may be nitrergic in nature.
Subject: Central nervous system
Intracerebroventricular
Nitric oxide inhibition
Insulin
Natriuresis
Lithium clearance
Editor: Associação Brasileira de Divulgação Científica
Rights: aberto
Identifier DOI: 10.1590/S0100-879X2009007500006
Address: http://dx.doi.org/10.1590/S0100-879X2009007500006
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2009001200013
Date Issue: 1-Dec-2009
Appears in Collections:Unicamp - Artigos e Outros Documentos

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