Roux-en-Y Gastric Bypass Improves Hepatic Glucose Metabolism Involving Down-Regulation of Protein Tyrosine Phosphatase 1B in Obese Rats.

Abstract

OBJECTIVE:

This study was initiated to investigate the effects of Roux-en-Y gastric bypass (RYGB) surgery on hepatic glucose metabolism and hepatic expression of protein tyrosine phosphatase 1B (PTP1B) in obese rats.

METHODS:

Body weight, glucose, intraperitoneal glucose, insulin, and pyruvate tolerance tests were performed pre- and postoperatively, and plasma lipid, insulin and glucagon-like peptide 1 (GLP-1) were measured. The mRNA levels of G6Pase, Pepck, Gsk-3β and Gys-2, and the expression levels of PTP1B mRNA, protein, and other components of the insulin signaling pathway were measured by using RT-PCR and western blotting. The intracellular localization of PTP1B and hepatic glycogen deposition was also observed.

RESULTS:

RYGB surgery-treated rats showed persistent weight loss, significantly improved glucose tolerance, pyruvate tolerance, and dyslipidemia, as well as increased insulin sensitivity, hepatic glycogen deposition and increased plasma GLP-1 in obese rats. RT-PCR analyses showed Pepck, G6Pase, and Gsk-3β mRNA to be significantly decreased, and Gys-2 mRNA to be significantly increased in liver tissue in the RYGB group (p < 0.05 vs. high-fat diet (HFD) or HFD + sham group); in addition, the expression of PTP1B were significantly decreased and insulin signaling were improved in the RYGB group (p < 0.05 vs. HFD or HFD + sham group).

CONCLUSION:

RYGB can improve hepatic glucose metabolism and down-regulate PTP1B in obese rats. An increased circulating GLP-1 concentration may be correlated with the effects following RYGB in obese rats.

• Authors: Song Mu, Jiayu Liu, Wei Guo, Shuping Zhang, Xiaoqiu Xiao, Zhihong Wang, Jun Zhang
• Journal: Obesity facts (Obes Facts) Vol. 10 Issue 3 Pg. 191-206 ( 2017) ISSN: 1662-4033 [Electronic] Switzerland
• PMID: 28564652 (Publication Type: Journal Article)
• Copyright: © 2017 The Author(s) Published by S. Karger GmbH, Freiburg.

Chemical References

• Blood Glucose
• Insulin
• RNA, Messenger
• Glucagon-Like Peptide 1
• Protein Tyrosine Phosphatase, Non-Receptor Type 1
• Glucose

Topics

• Animals
• Blood Glucose (metabolism)
• Body Weight (physiology)
• Down-Regulation
• Gastric Bypass
• Glucagon-Like Peptide 1 (blood)
• Glucose (metabolism)
• Insulin (blood)
• Insulin Resistance
• Liver (enzymology, metabolism)
• Male
• Obesity (enzymology, metabolism, surgery)
• Protein Tyrosine Phosphatase, Non-Receptor Type 1 (analysis, genetics)
• RNA, Messenger (analysis)
• Rats
• Rats, Sprague-Dawley