Tissue cholesterol content alterations in streptozotocin-induced diabetic rats.
OBJECTIVE
Diabetes is associated with elevated serum total cholesterol level and disrupted lipoprotein subfractions. The aim of this study was to examine alterations in the tissue cholesterol contents closely related to diabetic complications.


METHODS
Intraperitoneal injection of streptozotocin was used to induce type 1 diabetes in adult male Sprague-Dawley rats. On d 35 after the injection, liver, heart, intestine, kidney, pancreas, cerebral cortex and hippocampus were isolated from the rats. The content of total and free cholesterol in the tissues was determined using HPLC. The ATP-binding cassette protein A1 (ABCA1) protein and ApoE mRNA were measured using Western blot and QT-PCR analyses, respectively.


RESULTS
In diabetic rats, the level of free cholesterol was significantly decreased in the peripheral tissues, but significantly elevated in hippocampus, as compared with those in the control rats. Diabetic rats showed a trend of decreasing the total cholesterol level in the peripheral tissues, but significant change was only found in kidney and liver. In diabetic rats, the level of the ABCA1 protein was significantly increased in the peripheral tissues and cerebral cortex; the expression of ApoE mRNA was slightly decreased in hippocampus and cerebral cortex, but the change had no statistical significance.


CONCLUSIONS
Type 1 diabetes decreases the free cholesterol content in the peripheral tissues and increases the free cholesterol content in hippocampus. The decreased free cholesterol level in the peripheral tissues may be partly due to the increased expression of the ABCA1 protein.
Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing, China.
Xin-ting
XT
Wang
Jia
J
Li
Li
L
Liu
Nan
N
Hu
Shi
S
Jin
Can
C
Liu
Dan
D
Mei
Xiao-dong
XD
Liu
D064286:ATP Binding Cassette Transporter 1; D018528:ATP-Binding Cassette Transporters / Q000235:genetics; D000818:Animals; D001057:Apolipoproteins E / Q000235:genetics; D002784:Cholesterol / Q000032:analysis* / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D007328:Insulin / Q000032:analysis / Q000378:metabolism; D000071518:Liver X Receptors; D008297:Male; D057093:Orphan Nuclear Receptors / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley
D064286:ATP Binding Cassette Transporter 1; D018528:ATP-Binding Cassette Transporters; D001057:Apolipoproteins E; D007328:Insulin; D000071518:Liver X Receptors; D057093:Orphan Nuclear Receptors; D012333:RNA, Messenger; D002784:Cholesterol