Increased GLP-1 Response after Gavage-Administration of Glucose in UCP2-deficient Mice

H. Zhang; J. Li; Z. Li; Y. Luo

doi:10.1055/s-0031-1298017

Hormone and Metabolic Research, Table of Contents

Horm Metab Res 2012; 44(02): 86-90
DOI: 10.1055/s-0031-1298017

Original Basic

Increased GLP-1 Response after Gavage-Administration of Glucose in UCP2-deficient Mice

Authors

H. Zhang

¹The First Affiliated Hospital of Nanjing Medical University Nanjing, Jiangsu, China
J. Li

²The Jiangsu Diabetes Center, State Key Laboratory of Pharmaceutical Biotechnology, School of Biological Sciences, Nanjing University, Nanjing, Jiangsu, China
Z. Li

¹The First Affiliated Hospital of Nanjing Medical University Nanjing, Jiangsu, China
Y. Luo

²The Jiangsu Diabetes Center, State Key Laboratory of Pharmaceutical Biotechnology, School of Biological Sciences, Nanjing University, Nanjing, Jiangsu, China

Abstract

Although it has been widely reported that endogenous level of GLP-1 can be enhanced by various secretagogues, the mechanism of GLP-1 secretion in vivo is still not fully understood. In the present study, we assessed the possible effect of uncoupling protein 2 (UCP2) on GLP-1 secretion in gut. The levels of plasma GLP-1(7–36) amide/(7–37) in UCP2-deficient mice and wild-type mice were measured by applying ELISA technique. UCP2 mRNA and protein levels were detected in the gastrointestinal tract by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot analysis, respectively. The plasma GLP-1 levels in C57BL/6J mice had significantly increased to 6.9 pM (n=8, p<0.001) at 15 min after gavage-administration of glucose (2 g glucose/kg body weight), approximately 2-fold, compared with control group. Plasma GLP-1 levels were also significantly elevated at 30 min (p<0.001), but nearly returned to baseline levels at 60 min. UCP2-deficient mice had higher level of GLP-1 at various time points after administration of glucose (UCP2-deficient mice vs. wild type littermates, 15 min, 9.3±0.9 vs. 6.9±0.3, p<0.001; 30 min, 7.9±0.3 vs. 5.6±0.4, p<0.001; 60 min, 4.9±0.1 vs. 3.3±0.1, p<0.01). UCP2-deficient mice increased GLP-1 response to gavage-administration of glucose. Plasma GLP-1 level was not significantly altered after gavage-administration of saline. This study showed that plasma GLP-1 level increased after gastric glucose challenge, and UCP2 maybe serve as a negative regulator in glucose-induced GLP-1 secretion in mouse gut tract.

Key words

UCP2 - GLP-1 - gut - glucose - UCP2-deficient mice

Full Text

References

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