[The effect of high fat feeding and rosiglitazone intervention on pancreatic alpha cell in rats].
OBJECTIVE
To observe the effect of high-fat diet and rosiglitazone intervention on the function of pancreatic alpha cell of SD rats.


METHODS
36 normal male SD rats, 8-week old, were randomly divided into 3 groups i.e., a normal chow group (CC, n = 12), an isocaloric high-fat diet group (CF, n = 12), and a rosiglitazone-treated group (Ro, n = 12, rosiglitazone 3 mg.kg(-1).d(-1) and isocaloric high fat diet). Triglyceride (TG) was measured every 4 weeks after feeding for 6 weeks. After 28 weeks, the secretion of insulin and glucagon (Gg) was assessed with intravenous glucose tolerance test (IVGTT) at 0, 3, 5, and 10 minutes. (3)H-2-deoxyglucose ((3)H-2-DG) uptake by tissues was measured to evaluate the insulin sensitivity.


RESULTS
The ratio of intra-abdominal fat mass and body weight was higher in the rats of CF and Ro group than that in the rats of CC group. At the first 10 min of IVGTT, the Gg level was higher in the CF group than that in CC group [(119.3 +/- 12.4, 82.3 +/- 6.4, 72.2 +/- 5.8, 68.2 +/- 9.1) ng/L vs (96.8 +/- 9.1, 67.6 +/- 5.9, 57.9 +/- 5.3, 55.3 +/- 6.9) ng/L, P < 0.05] and Ro group [(78.4 +/- 6.0, 59.4 +/- 4.0, 49.9 +/- 6.2, 40.9 +/- 6.0) ng/L, P < 0.01], the level was even lower in the latter group than in CC group (P < 0.01). There was no difference of insulin level among the 3 groups. By using quantitative image analysis, the integrated A (area x A) of alpha cells was significantly higher in the CF group and Ro group as compared with that in the CC group (1661 +/- 130 and 1532 +/- 132 vs 1188 +/- 104, P < 0.05). In contrast, there was no difference among the 3 groups in the integrated A of beta cells.


CONCLUSIONS
High-fat feeding induces insulin resistance in rats, which is associated with pancreatic alpha cell proliferation and abnormal Gg secretion.
Wang
Xin
X
Department of Endocrinology, China-Japan Friendship Hospital, Beijing 100029, China.
Yang
Wen-ying
WY
Xiao
Jian-zhong
JZ
Zhao
Wen-hui
WH
Wang
Na
N
Liu
Xue-li
XL
Pan
Lin
L
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D049109:Cell Proliferation / Q000187:drug effects; D004041:Dietary Fats / Q000009:adverse effects*; D050416:Glucagon-Secreting Cells / Q000187:drug effects / Q000502:physiology*; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D000077154:Rosiglitazone; D045162:Thiazolidinediones / Q000494:pharmacology*
D001786:Blood Glucose; D004041:Dietary Fats; D007004:Hypoglycemic Agents; D007328:Insulin; D045162:Thiazolidinediones; D000077154:Rosiglitazone