EFFECTS OF TRIAMCINOLONE ON BRAIN AND CEREBROSPINAL-FLUID APOLIPOPROTEIN-E LEVELS IN RATS

The effects of the short term administration of triamcinolone (0.5 mg per 100 g body weight, 5 days) on apolipoprotein E and A-I concentrati ons in cerebrospinal fulid (CSF), brain extract and serum were studied in male Wistar rats using enzyme immunoassays. ApoE was significantly increased by triamcinolone in apoE-rich HDL(1) in serum; 40+/-13 (mea n+/-SD) vs. 68+/-23 mg/dl(15 saline-treated rats vs. 11 triamcinolone- treated rats)(P<0.01), which was paralleled by an increase in serum ap oA-I (76+/-21 vs. 184+/-24 mg/dl), while serum lipids also increased s ignificantly. No significant difference was observed in the apoE conce ntrations in CSF (296+/-170 vs. 269+/-67 mu g/dl) or brain extract (5. 0+/-1.6 vs. 5.7+/-1.8 mu g/g wet weight). The apoA-I concentrations fo und in CSF and brain extract were much lower than those for apoE and w ere not appreciably affected by triamcinolone: 7.7+/-5.5 vs. 4.5+/-3.1 mu g/dl for CSF and <0.5 vs. <0.5 mu g/g wet weight for brain extract . The apo E metabolism in the rat central nervous system appears to be refractory to the short term administration of triamcinolone and to c hanges in the serum lipoprotein metabolism. ApoA-I appears unlikely to play a significant role in the rat central nervous system.