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Reduced glucose‐induced insulin secretion in low‐protein‐fed rats is associated with altered pancreatic islets redox status
Author(s) -
Cappelli Ana Paula G.,
Zoppi Claudio C.,
Silveira Leonardo R.,
Batista Thiago M.,
Paula Flávia M.,
da Silva Priscilla M. R.,
Rafacho Alex,
BarbosaSampaio Helena C.,
Boschero Antonio C.,
Carneiro Everardo M.
Publication year - 2018
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.25908
Subject(s) - medicine , endocrinology , pancreatic islets , insulin , superoxide dismutase , glutathione peroxidase , catalase , glutathione , chemistry , l glucose , gpx1 , antioxidant , carbohydrate metabolism , oxidative stress , biology , islet , enzyme , biochemistry
In the present study, we investigated the relationship between early life protein malnutrition‐induced redox imbalance, and reduced glucose‐stimulated insulin secretion. After weaning, male Wistar rats were submitted to a normal‐protein‐diet (17%‐protein, NP) or to a low‐protein‐diet (6%‐protein, LP) for 60 days. Pancreatic islets were isolated and hydrogen peroxide (H 2 O 2 ), oxidized (GSSG) and reduced (GSH) glutathione content, CuZn‐superoxide dismutase (SOD1), glutathione peroxidase (GPx1) and catalase (CAT) gene expression, as well as enzymatic antioxidant activities were quantified. Islets that were pre‐incubated with H 2 O 2 and/or N‐acetylcysteine, were subsequently incubated with glucose for insulin secretion measurement. Protein malnutrition increased CAT mRNA content by 100%. LP group SOD1 and CAT activities were 50% increased and reduced, respectively. H 2 O 2 production was more than 50% increased whereas GSH/GSSG ratio was near 60% lower in LP group. Insulin secretion was, in most conditions, approximately 50% lower in LP rat islets. When islets were pre‐incubated with H 2 O 2 (100 μM), and incubated with glucose (33 mM), LP rats showed significant decrease of insulin secretion. This effect was attenuated when LP islets were exposed to N‐acetylcysteine.