Vitamin E improves microsomal phospholipase A2 activity and the arachidonic acid cascade in kidney of diabetic rats.
The purpose of the present study was to investigate the effects of vitamin E on microsomal phospholipase A2 activity and the arachidonic acid cascade in the kidneys of streptozotocin (STZ)-induced diabetic rats. Sprague-Dawley male rats weighing 100 +/- 10 g were randomly assigned to one normal and three STZ-induced diabetic groups. The diabetic groups were fed a vitamin E-free diet (the DM-0E group), 40 mg vitamin E/kg diet (the DM-40E group) or a 400 mg vitamin E/kg diet (the DM-400E group). The kidney vitamin E concentrations were 59 and 49% lower in the DM-0E and DM-40E groups, respectively, than in the normal group. The kidney thiobarbituric acid reactive substance concentrations in the DM-0E, DM-40E and DM-400E groups were 119, 84 and 33% greater, respectively, than that in the normal group. The concentration in the DM-400E group was 39% lower than that in the DM-0E group. The phospholipase A2 (PLA2) activity in the kidney microsomes of the DM-0E-40E and DM-400E groups were 88, 58 and 35% greater, respectively, than that in the normal group. The activity in the DM-400E group was 28% lower than that in the DM-0E group and 16% lower than that in the DM-40E group. The differences in the phospholipids in the kidney microsomes included reductions in the phosphatidylcholine and phosphatidylethanolamine compositions. Phosphatidylethanolamine hydrolysis in the kidney microsomes of the DM-0E and DM-40E groups were 84 and 64%, which did not differ from the DM-400E group. The formation of thromboxane A2 (TXA2) in the kidney microsomes was 137 and 70% greater in the DM-0E and DM-40E groups, respectively, than in the normal group. TXA2 formation did not differ between the DM-400E and normal groups. The formation of prostacyclin in the kidney microsomes was 60 and 44% lower in the DM-0E and DM-40E groups, respectively, than in the normal group, whereas the DM-400E group did not differ from that in the normal group. The ratio of prostacyclin to TXA2 was 82 and 65% lower than normal in the DM-0E and DM-40E groups, respectively. Kidney function appears to be improved by vitamin E supplementation due to its antithrombus action, which in turn controls the arachidonic acid cascade system.
Kwag
O G
OG
Department of Nursing Science, Taegu Science College, Taegu, Korea 702-722.
Kim
S O
SO
Choi
J H
JH
Rhee
I K
IK
Choi
M S
MS
Rhee
S J
SJ
D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology*; D011464:Epoprostenol / Q000096:biosynthesis; D006868:Hydrolysis; D007668:Kidney / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008861:Microsomes / Q000201:enzymology* / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D010713:Phosphatidylcholines / Q000378:metabolism; D010714:Phosphatidylethanolamines / Q000378:metabolism; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D051381:Rats; D017207:Rats, Sprague-Dawley; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D013928:Thromboxane A2 / Q000096:biosynthesis; D014810:Vitamin E / Q000494:pharmacology*
D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D017392:Thiobarbituric Acid Reactive Substances; D014810:Vitamin E; D016718:Arachidonic Acid; D013928:Thromboxane A2; D011464:Epoprostenol; D010741:Phospholipases A; D054467:Phospholipases A2