title: Effects of green tea catechin on phospholipase A2 activity and antithrombus in streptozotocin diabetic rats.
abstract: The purpose of this study was to investigate the effects of dietary green tea catechin on phospholipase A2 (PLA2) activity and the antithrombotic reaction of platelets in streptozotocin (STZ)-diabetic rats. Sprague-Dawley male rats weighing 100 +/- 10 g were randomly divided into one normal and three STZ-diabetic groups, which were subdivided into catechin-free group (DM-0C), 0.5% catechin group (DM-0.5C) and 1% catechin group (DM-1C). The activity level of platelet phospholipase A2 was higher in the diabetic groups than in the normal group, while it was lower in DM-0.5C and DM-1C than in DM-0C. The activity of platelet cyclooxygenase in DM-0C was 1.1-fold as high as in the normal group, but was significantly reduced by catechin supplementation. The platelet thromboxane A2 (TXA2) formation became higher in DM-0C as compared to the normal group, but not in DM-0.5C and DM-1C. The synthesis of aortic prostacyclin (PGI2) was lower in DM-0C and DM-0.5C than in the normal group. The PGI2/TXA2 ratio was decreased to 55% in DM-0C, but was restored by catechin supplementation. These results indicate that STZ-diabetic rats are sensitive to platelet aggregation and thrombosis, and that the abnormality can be improved by dietary catechin.
authors.affiliation: Department of Food Science and Nutrition, Catholic University of Taegu-Hyosung, Kyungbuk, Korea.
authors.forename: J A
authors.initials: JA
authors.lastname: Yang
authors.forename: J H
authors.initials: JH
authors.lastname: Choi
authors.forename: S J
authors.initials: SJ
authors.lastname: Rhee
mesh_terms: D000818:Animals; D001011:Aorta / Q000378:metabolism; D001792:Blood Platelets / Q000378:metabolism; D002392:Catechin / Q000494:pharmacology* / Q000627:therapeutic use; D003921:Diabetes Mellitus, Experimental / Q000097:blood* / Q000150:complications; D011464:Epoprostenol / Q000096:biosynthesis; D008297:Male; D010741:Phospholipases A / Q000097:blood*; D054467:Phospholipases A2; D010974:Platelet Aggregation; D011451:Prostaglandin-Endoperoxide Synthases / Q000097:blood; D051381:Rats; D017207:Rats, Sprague-Dawley; D013662:Tea / Q000737:chemistry*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D013927:Thrombosis / Q000209:etiology / Q000517:prevention & control*; D013928:Thromboxane A2 / Q000097:blood; D013930:Thromboxane-A Synthase / Q000378:metabolism
chemical_list: D013662:Tea; D017392:Thiobarbituric Acid Reactive Substances; D013928:Thromboxane A2; D002392:Catechin; D011464:Epoprostenol; D011451:Prostaglandin-Endoperoxide Synthases; D010741:Phospholipases A; D054467:Phospholipases A2; D013930:Thromboxane-A Synthase