Increased Plasma Dipeptidyl Peptidase IV (DPP IV) Activity and Decreased DPP IV Activity of Visceral But Not Subcutaneous Adipose Tissue in Impaired Glucose Tolerance Rats Induced by High-Fat or High-Sucrose Diet

Abstract

Several studies have investigated whether dipeptidyl peptidase IV (DPP IV) activity is correlated to the severity of diabetes; however, it remains unclear. To investigate the roles of DPP IV activity in metabolic abnormalities, impaired glucose tolerance rats were produced using a high-fat (HF) or high-sucrose (HS) diet. HF dietfed rats obviously exhibited impaired glucose tolerance, with increases in subcutaneous and epididymal fat mass, insulin resistance and dyslipidaemia. In rats fed a HS diet rather than a normal diet, lower body weight and fasting blood glucose were observed temporarily in the early period after HS diet feeding; however, impaired glucose tolerance was evoked to some extent with an increase in epididymal fat mass. Both HF and HS diet-fed rats showed significantly higher plasma DPP IV activity than normal diet-fed rats, in the order of HF dietϾHS dietϾnormal diet. HF and HS diets did not significantly affect DPP IV activity and mRNA expression in the kidney. On the other hand, HF, but not HS, diet caused a significant decrease in DPP IV activity in the liver as compared to the control. Of note, both HF and HS diets caused a significant decrease in DPP IV activity in epididymal fat, even though they did not change DPP IV activity in subcutaneous fat. In conclusion, HF or HS diet-induced impaired glucose tolerance with visceral fat accumulation may be interrelated with increased plasma DPP IV activity and decreased DPP IV activity of visceral but not subcutaneous adipose tissue.

Plasma dipeptidyl peptidase 4 activity correlates with body mass index and the plasma adiponectin concentration in healthy young people

“…Previously, we found that plasma DPP4 activity was significantly greater in impaired glucose tolerance rats fed a high-fat or high-sucrose diet than in normal rats [6]. Additionally, using Otsuka Long-Evans Tokushima fatty rats, which display a spontaneously hyperphagic and obese phenotype in combination with hyperglycemia and hyperinsulinemia, we showed that plasma DPP4 activity changes in accordance with the progression of hyperinsulinemic obesity and pancreatic islet atrophy [7].…”

“…Although several clinical studies have investigated whether DPP4 activity is correlated with the onset or severity of diabetes and/or obesity, they have produced mixed results; i.e., plasma DPP4 activity levels were of 7-amino-4-methylcoumarin (AMC) from the synthetic substrate H-glycyl-prolyl-AMC (Gly-Pro-AMC; Sigma, St. Louis, MO, U.S.A.), as described previously [6][7][8]. Briefly, 5 μL of plasma were mixed with 35 μL of assay buffer (25 mmol/L HEPES, 140 mmol/L NaCl, 80 mmol/L MgCl 2 , and 1 % BSA; pH 7.8).…”

Combining sitagliptin/metformin with a functional fiber delays diabetes progression in Zucker rats

“…Changes in DPP4 activity and Dpp4 mRNA levels may provide partial insights into the differences in the observed active GLP1 concentrations. DPP4 is a serine protease that inactivates polypeptides such as GLP1 and is expressed on the surface of various types of cells, including the small intestine, kidney, liver, and in a soluble form in plasma (Kirino et al 2009). While DPP4 activity in the plasma of S/MET and PGXCS/MET rats did not differ, there was a significant reduction in DPP4 activity in the kidney of PGXCS/MET rats compared with S/MET.…”

“…Total cholesterol concentration was measured in the blood using an automated analyzer (Polymer Technology Systems, CardioChek, PA, USA). Plasma DPP4 activity was measured according to Kirino et al (2009). A clinical chemistry panel was analyzed in serum and included: blood urea nitrogen, glucose, electrolytes, creatinine, alkaline phosphatase, aspartate aminotransferase (ALT), alanine aminotransferase (AST), and bilirubin.…”

High Fat and High Cholesterol Diet Induces DPP-IV Activity in Intestinal Lymph

“…in DPP-IV in the intestine and kidney associated with a high fat diet 5 , while Kirino et al found that a high fat diet increased plasma DPP-IV activity 6 . Lamers et al reported that DPP-IV release was strongly correlated with adipocyte size, potentially representing an important source of DPP-IV in obesity 7 .…”