動脈硬化性疾患における血漿PDGF (血小板由来増殖因子)濃度と血小板活性化マーカーの変動

Abstract

To determine the plasma level of the plateletderived growth factor (PDGF) and evaluate its significance, the plasma PDGF of 48 elderly patients with varying degrees of atherosclerosis was determined.According to brain CT findings, the ankle pressure index (API) and angiographic findings (cerebral/peripheral), the patients were divided into 3 groups with a differing degrees of atherosclerosis as follows; Group 1 (diffuse, severe) suffered from cortical cerebral infarction due to main trunk obstruction (A) and decreased API (<0.9)(B), Group II (focal, severe) suffered from either (A) or (B), and Group III (mild) did not suffer from either (A) or (B).Plasma PDGF concentrations were determined by RIA using the method described by Bannai. In addition, the β-thromboglobulin (β-TG), platelet factor 4 (PF4), 11-dehydrothromboxane B2 (11-DTXB2), and 6-keto-prostaglandin F1α (6-keto-PGF1α) levels were compared among all the groups, and to the levels found in young healthy controls.The mean PDGF level was 672±1105pg/ml, 220±132pg/ml, and 288±140pg/ml in group I (n=12), group II (n=20), and group III (n=16), respectively.This level did not significantly differ from one group to another, but was higher than the level found in the controls (163±47pg/m/: n=5).The mean β-TG, PF4, and 11-DTXB2 levels were also significantly elevated in these three groups compared with the controls, while the mean 6-keto-PGF1α level was lower, although this was not significant.PDGF revealed a positive correlation with PF4 and β-TG, and was especially strongly correlated with PF4 (r=0.6).These findings suggest that, as PF4 usually binds with endothelial cells soon after it is released from the platelets into the circulation, PDGF may also bind immediately to tissues near endothelial lesions.In conclusion, it appears that plasma PDGF levels do not always reflect the severity of a patient's atherosclerosis.