Exercise training decreases proinflammatory profile in Zucker diabetic (type 2) fatty rats.
OBJECTIVE
In the present study we evaluated the effect of exercise on the plasma levels of proinflammatory cytokines, interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha), and the anti-inflammatory molecule uric acid in the Zucker diabetic fatty (ZDF) rats that are more prone to develop type 2 diabetes mellitus.


METHODS
Sixteen obese ZDF (Gmi fa/fa) rats (8 wk old, 228.40 +/- 4.05 g) were randomly assigned to one of two groups (n = 8 each): an exercise-trained group and a sedentary one. In addition, 16 lean ZDF (Gmi +/+) rats (8 wk old, 199.00 +/- 3.50 g) were subjected to identical sedentary and exercise conditioning (n = 8 each). Initially, rats swam 15 min/d (5 d/wk) in a 36 degrees C bath. The exercise protocol was gradually increased by 15 min/d until a swimming period of 1 h/d (1 wk) was attained. Thereafter, rats swam 1 h/d, 3 d/wk, for an additional period of 11 wk. Rats were sacrificed 48 h after the last training period and the blood and pancreas were collected. Circulating levels of glucose, glycosylated hemoglobin, total cholesterol, triglycerides, insulin, uric acid, IL-6, and TNF-alpha were assessed. The concentrations of proinflammatory cytokines in the pancreas were also evaluated.


RESULTS
In the diabetic ZDF (fa/fa) rats, exercise decreased hyperuricemia (-37.3%) and IL-6 and TNF-alpha levels (-16.9% and -12.7% respectively) and maintained the weight of the pancreas at near normal. Immunohistochemistry revealed a marked decrease in the expression of TNF-alpha and IL-6 in the pancreatic islet cells of ZDF (fa/fa) rats.


CONCLUSIONS
These results indicate that aerobic exercise is anti-inflammatory in nature.
Teixeira de Lemos
E
E
Therapeutics Unit, Institute of Pharmacology and Experimental Therapeutics, Medicine Faculty, Coimbra University, Coimbra, Portugal; Polytechnic Institute of Viseu, Viseu, Portugal.
Reis
F
F
Baptista
S
S
Pinto
R
R
Sepodes
B
B
Vala
H
H
Rocha-Pereira
P
P
Correia da Silva
G
G
Teixeira
N
N
Silva
A Santos
AS
Carvalho
L
L
Teixeira
F
F
Das
U N
UN
D000818:Animals; D030801:Animals, Genetically Modified; D001786:Blood Glucose / Q000032:analysis; D002784:Cholesterol / Q000097:blood; D016207:Cytokines / Q000097:blood*; D003921:Diabetes Mellitus, Experimental / Q000097:blood*; D006442:Glycated Hemoglobin / Q000032:analysis; D007150:Immunohistochemistry; D007328:Insulin / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D009929:Organ Size; D010179:Pancreas / Q000378:metabolism*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D011897:Random Allocation; D051381:Rats; D011924:Rats, Zucker; D013550:Swimming; D014280:Triglycerides / Q000097:blood; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D014527:Uric Acid / Q000097:blood*
D001786:Blood Glucose; D002784:Cholesterol; D016207:Cytokines; D006442:Glycated Hemoglobin; D007328:Insulin; D015850:Interleukin-6; D014280:Triglycerides; D014409:Tumor Necrosis Factor-alpha; D014527:Uric Acid