Please use this identifier to cite or link to this item:
Type: Artigo de periódico
Title: Extra-pancreatic insulin production in RAt lachrymal gland after streptozotocin-induced islet beta-cells destruction
Author: Cunha, DA
de Alves, MC
Stoppiglia, LF
Jorge, AG
Modulo, CM
Carneiro, EM
Boschero, AC
Saad, MJA
Velloso, LA
Rocha, EM
Abstract: Previous work has revealed that insulin is secreted in the tear film; its mRNA is expressed in the lachrymal gland (LG) and its receptor in tissues of the ocular surface. To test the hypothesis of insulin production in the LG, we compared normal and diabetic rats for: (1) the presence of insulin and C-peptide, (2) glucose- and carbachol-induced insulin secretion ex-vivo, and (3) biochemical and histological characteristics of diabetic LG that would support this possibility. Four weeks after streptozotocin injection, blood and tears were collected from streptozotocin-diabetic male Wistar rats. Insulin levels in the tear film rose after glucose stimulation in diabetic rats, but remained unchanged in the blood. Ex vivo static secretion assays demonstrated that higher glucose and 200 mu M carbachol significantly increased mean insulin levels from LG samples of both groups. Insulin and C-peptide were expressed in LG of diabetic rats as determined by RIA. Comparable synaptophysin immune staining and peroxidase activity in the LG of both groups suggest that the structure and function of these tissues were maintained. These findings provide evidence of insulin production by LG. Higher expression of reactive oxygen species scavengers may prevent oxidative damage to LG compared to pancreatic beta-cells. (C) 2007 Elsevier B.V. All rights reserved.
Subject: lachrymal gland
diabetes mellitus
dry eye
hormone peptides
reactive oxygen species
Country: Holanda
Editor: Elsevier Science Bv
Citation: Biochimica Et Biophysica Acta-general Subjects. Elsevier Science Bv, v. 1770, n. 8, n. 1128, n. 1135, 2007.
Rights: fechado
Identifier DOI: 10.1016/j.bbagen.2007.05.002
Date Issue: 2007
Appears in Collections:Unicamp - Artigos e Outros Documentos

Files in This Item:
File Description SizeFormat 
WOS000248501000006.pdf1.15 MBAdobe PDFView/Open

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