To study the pathophysiological significance of platelets in arteriosclerosis, serum lipoperoxide (s-LPO) and released platelet LPO aggregation by thrombin (p-LPO production) were measured in 20 normal subjects and in the following with arteriosclerotic diseases; 32 of ischemic heart disease (IHD), 7 of hyperlipemia (HL), 13 of diabetes mellitus (DM), 34 of hypertension (HT) and 30 of cerebral vessel disease (CVD).
Serum LPO levels were significantly higher in following groups of patients, 3.17±1.77nmol/ml in IHD, 3.63±0.62nmol/ml in HL, 4.00±2.39nmol/ml in DM, 2.93±1.19nmol/m/ in HT and 3.16±1.23nmol/ml in CVD, than in normal subjects of 1.75±0.56nmol/ml.
Levels of p-LPO production were 8.75±3.18nmol/109 platelets in normal subjects, 13.15±8.71nmol/109 platelets in IHD, 14.23±6.13nmol/109 platelets in HL, 12.49±9.18nmol/109 platelets in DM, 11.26±8.08nmol/109 platelets in HT and 12.31±12.11nmol/109 platelets in CVD.
Levels of p-LPO in HL were significantly higher than those in normal subjects. Positive correlation-ship between p-LPO production and s-LPO levels were observed in patients with IHD, HL, DM, HT and CVD.
In treadmill stress test, patients were divided to three groups according to % change of p-LPO production, ; i. e., Group I with increased +10% upper of p-LPO production, Group II within equivocal (±10%) of p-LPO production, and Group III with decreased -10% lower after treadmill test.
There was a reverse correlation (p<0.02) between after-before (A-B) difference of p-LPO production and those of s-LPO levels measured before (B) and after (A) treadmill stress test.
Platelet adhesiveness was significantly increased in after treadmill stress test. Maximum platelet aggregation rates to ADP, adrenaline and collagen were increased in group I, but those in group III were decreased.
In group III, there were higher p-LPO production levels and higher platelet aggregation rates before treadmill stress test than other two groups. ST depression was significant in all cases of group III after treadmill stress test.
