Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/195501
Type: Artigo de periódico
Title: Effect Of Intracerebroventricularly Injected Insulin On Urinary Sodium Excretion By Cerebroventricular Streptozotocin-treated Rats.
Author: Macedo, R F
Furlan, F C
Marshall, P S
Michelotto, J B
Gontijo, J A R
Abstract: Recent evidence suggests that insulin may influence many brain functions. It is known that intracerebroventricular (icv) injection of nondiabetogenic doses of streptozotocin (STZ) can damage insulin receptor signal transduction. In the present study, we examined the functional damage to the brain insulin receptors on central mechanisms regulating glomerular filtration rate and urinary sodium excretion, over four periods of 30 min, in response to 3 microl insulin or 0.15 NaCl (vehicle) injected icv in STZ-treated freely moving Wistar-Hannover rats (250-300 g). The icv cannula site was visually confirmed by 2% Evans blue infusion. Centrally administered insulin (42.0 ng/ micro l) increased the urinary output of sodium (from 855.6 85.1 to 2055 310.6 delta%/min; N = 11) and potassium (from 460.4 100 to 669 60.8 delta%/min; N = 11). The urinary sodium excretion response to icv insulin microinjection was markedly attenuated by previous central STZ (100 micro g/3 micro l) administration (from 628 45.8 to 617 87.6 delta%/min; N = 5) or by icv injection of a dopamine antagonist, haloperidol (4 micro g/3 micro l) (from 498 +/- 39.4 to 517 +/- 73.2 delta%/min; N = 5). Additionally, insulin-induced natriuresis occurred by increased post-proximal tubule sodium rejection, despite an unchanged glomerular filtration rate. Excluding the possibility of a direct action of STZ on central insulin receptor-carrying neurons, the current data suggest that the insulin-sensitive response may be processed through dopaminergic D1 receptors containing neuronal pathways.
Subject: Animals
Antibiotics, Antineoplastic
Brain
Glomerular Filtration Rate
Injections, Intraventricular
Injections, Subcutaneous
Insulin
Male
Natriuresis
Rats
Rats, Wistar
Receptor, Insulin
Signal Transduction
Streptozocin
Time Factors
Rights: aberto
Identifier DOI: 
Address: http://www.ncbi.nlm.nih.gov/pubmed/12937785
Date Issue: 2003
Appears in Collections:Unicamp - Artigos e Outros Documentos

Files in This Item:
File SizeFormat 
pmed_12937785.pdf448.55 kBAdobe PDFView/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.