S. Swami et al., EFFECTS OF STREPTOZOTOCIN-INDUCED DIABETES ON LOW-DENSITY-LIPOPROTEINRECEPTOR EXPRESSION IN RAT ADIPOSE-TISSUE, Journal of lipid research, 37(2), 1996, pp. 229-236
Low density lipoprotein (LDL) receptors are found in most cells, inclu
ding adipose cells. LDL receptors are primarily regulated by cellular
cholesterol content. Insulin and insulin deficiency have been reported
to have varying effects on LDL receptors in various tissues. The pres
ent study was undertaken to assess the in vivo effects of streptozotoc
in-induced diabetes on LDL receptor expression and cholesterol content
in adipose tissue and liver. Diabetes was induced by a single dose of
streptozotocin. After 3 days, some animals were treated with insulin,
and all animals were killed 10 days after induction of diabetes. Comp
ared to control rats, 10 days of diabetes caused a decrease in adipose
cell size and cellular unesterified cholesterol and cholesteryl ester
s, and insulin treatment returned these towards normal. No changes wer
e observed in hepatic lipid content with diabetes or insulin treatment
. Diabetes was associated with an similar to 50% reduction in immunore
active LDL receptors in adipose cells (P < 0.01) that was returned to
normal with insulin treatment. The levels of LDL receptor mRNA decreas
ed similar to 80% (P < 0.001) in adipose cells isolated from streptozo
tocin-induced diabetic rats and returned to normal with insulin treatm
ent. Hepatic LDL receptors and mRNA levels were unaffected by diabetes
or insulin treatment. In conclusion, diabetes decreased LDL receptor
expression in adipose cells while total cellular cholesterol content a
lso declined.