Reciprocal changes in leptin and tumor necrosis factor-alpha with exercise in insulin resistant rats.
Leptin and tumor necrosis factor--alpha(TNF-alpha) are important mediators of insulin resistance in obese subjects through their over-expression in adipose tissue. Secretion of leptin into the circulation is a signal for the brain in patients with hyperinsulinemia. Regulation of TNF-alpha affects adipocyte insulin sensitivity and lipid accumulation. Exercise training has been suggested for the prevention and treatment of such disorders. However, how exercise modifies secretion of leptin and TNF-alpha is not known. We investigated leptin and TNF-alpha in a rat model of insulin resistance induced by sucrose. After 4 weeks of sucrose feeding, 4 weeks of voluntary wheel running significantly reduced the concentrations of leptin in mesenteric (MS) and subcutaneous fat (SC) when compared to sedentary sucrose-feeding rats. These results suggest that exercise controls cytokine regulation of leptin and TNF-alpha. The increased TNF-alpha in adipose tissue may activate cytolysis for energy consumption.
Baba
T
T
Department of Laboratory Medicine, Gunma University School of Medicine, Maebashi, Japan.
Kanda
T
T
Yoshida
A
A
Tsukui
S
S
Nara
M
M
Inukai
T
T
Umeda
T
T
Tamura
J
J
Kobayashi
I
I
D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism; D000273:Adipose Tissue / Q000378:metabolism / Q000502:physiology; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight; D002149:Energy Intake; D007150:Immunohistochemistry; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance / Q000502:physiology*; D020738:Leptin / Q000378:metabolism*; D050356:Lipid Metabolism; D008297:Male; D005082:Physical Exertion / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D001786:Blood Glucose; D007328:Insulin; D020738:Leptin; D014409:Tumor Necrosis Factor-alpha