J Korean Med Sci.  1999 Oct;14(5):539-545. 10.3346/jkms.1999.14.5.539.

Surgical removal of visceral fat decreases plasma free fatty acid and increases insulin sensitivity on liver and peripheral tissue in monosodium glutamate (MSG)-obese rats

• Kim YW
• Kim JY
• Lee SK

• KMID: 646022
• DOI: http://doi.org/10.3346/jkms.1999.14.5.539

Abstract

In order to evaluate the role of visceral and subcutaneous fat tissue in insulin sensitivity and lipid metabolism, we measured the fasting levels of plasma free fatty acid (FFA) and insulin, glucose disappearance rate (Rd), and hepatic glucose production rate (HGP) after surgical removal of visceral (VF) or subcutaneous (SF) fat tissue in monosodium glutamate-obese (MSG-Ob) rats. Monosodium glutamate obesity was induced in rats by neonatal injection of MSG. Surgery to remove fat was done at 15 weeks of age. The experiments were done four weeks after the surgery. MSG-Ob rats showed increased levels of FFA, insulin, and HGP and decreased Rd compared to normal rats. In the VF group, the FFA level and HGP were decreased to normal values, Rd was partially normalized, but the level of insulin did not change significantly compared to MSG-Ob. In the SF group, FFA and Rd were partially normalized, but HGP was not suppressed significantly compared to MSG-Ob. These results suggest that visceral fat affects the insulin sensitivity of liver and FFA concentration more than subcutaneous fat; however, no significant difference was shown on whole body insulin sensitivity and fasting insulin concentration.

Keyword

Obesity; Rats; Viscera; Adipose tissue; Insulin resistance; Liver; Fatty acids, nonesterified; Glucose clamp thchnique

MeSH Terms

Adipose Tissue/surgery*
Adipose Tissue/metabolism*
Animal
Body Composition
Cholesterol/blood
Fatty Acids, Nonesterified/blood*
Glucose Clamp Technique
Glycogen Synthase/metabolism
Insulin/blood*
Liver/metabolism*
Male
Muscle, Skeletal/enzymology
Obesity/surgery*
Obesity/metabolism*
Obesity/chemically induced
Rats
Rats, Sprague-Dawley
Sodium Glutamate
Triglycerides/blood