Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/74667
Type: Artigo de periódico
Title: Subsensitivity to insulin in adipocytes from rats submitted to foot-shock stress
Author: Farias-Silva, E
Sampaio-Barros, MM
Amaral, MEC
Carneiro, EM
Boschero, AC
Grassi-Kassisse, DM
Spadari-Bratfisch, RC
Abstract: We examined the effect of three daily foot-shock stress sessions on glucose homeostasis, insulin secretion by isolated pancreatic islets, insulin sensitivity of white adipocytes, and glycogen stores in the liver and soleus muscle of rats. Stressed rats had plasma glucose (128.3 +/- 22.9 mg/dL) and insulin (1.09 +/- 0.33 ng/mL) levels higher than the controls (glucose, 73.8 +/- 3.5 mg/dL; insulin, 0.53 +/- 0.11 ng/mL, ANOVA plus Fisher's test; p < 0.05). After a glucose overload, the plasma glucose, but not insulin, levels remained higher (area under the curve 8.19 &PLUSMN; 1.03 vs. 4.84 &PLUSMN; 1.33 g/dL 30 min and 102.7 &PLUSMN; 12.2 vs. 93.2 &PLUSMN; 16.1 ng/mL 30 min, respectively). Although, the area under the insulin curve was higher in stressed (72.8 &PLUSMN; 9.8 ng/mL) rats than in control rats (34.9 &PLUSMN; 6.9 ng/mL) in the initial 10 min after glucose overload. The insulin release stimulated by glucose in pancreatic islets was not modified after stress. Adipocytes basal lipolysis was higher (stressed, 1.03 &PLUSMN; 0.14; control, 0.69 &PLUSMN; 0.11 &mu;mol of glycerol in 60 min/100 mg of total lipids) but maximal lipolysis stimulated by norepinephrine was not different (stressed, 1.82 &PLUSMN; 0.35; control, 1.46 &PLUSMN; 0.09 &mu;mol of glycerol in 60 min/100 mg of total lipids) after stress. Insulin dose-dependently inhibited the lipolytic response to norepinephrine by up to 35% in adipocytes from control rats but had no effect on adipocytes from stressed rats. The liver glycogen content was unaltered by stress, but was lower in soleus muscle from stressed rats than in control rats (0.45 &PLUSMN; 0.04 vs. 0.35 &PLUSMN; 0.04 mg/100 mg of wet tissue). These results suggest that rats submitted to foot-shock stress develop hyperglycemia along with hyperinsulinemia as a consequence of insulin subsensitivity in adipose tissue, with no alteration in the pancreatic sensitivity to glucose. Foot-shock stress may therefore provide a useful short-term model of insulin subsensitivity.
Subject: glucose tolerance test
white adipocytes
lipolysis
pancreatic islets
insulin release
soleus muscle
liver glycogen
Country: Canadá
Editor: Natl Research Council Canada
Rights: fechado
Identifier DOI: 10.1139/Y02-104
Date Issue: 2002
Appears in Collections:Artigos e Materiais de Revistas Científicas - Unicamp

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