抄録
Thirteen patients with arteriosclerotic diseases and 5 normal healthy subjects were orally given 300mg aspirin once daily for 4 consecutive weeks. Examinations with a stress on platelet functions were carried out before and after the first administration and during at the end of 4 weeks of treatment to clarify the influence of aspirin on them. The following results were obtained:
1) The serum lipid (total cholesterol, triglycerides and HDL-cholesterol) levels and the atherogenic index were not significantly different before and after the consecutive daily administration of aspirin in both groups.
2) The proportion of arachidonic acid (C: 20:4) to the phospholipid (PE and PC) levels and NEFA in plasma and platelet produced no significant changes before and after the consecutive daily administration of aspirin.
3) The platelet aggregation tended to return to the pretreatment level 24 hours after the first administration in the group of normal healthy subjects, but this tendency was not clear in the group of patients with arteriosclerosis. In addition, the 24 hour values during the consecutive daily administration showed a similar tendency.
4) With regard to the influence on prostanoids, the ratio of TXB2 to 6-Keto-PGF1α decreased after the first administration, but it showed little alternation throughout the day and was maintained at a lower level constantly during the consecutive daily administration in both groups. When the range of fluctuation was examined by defining the pretreatment value as 100%, TXB2 was primarily suppressed in both groups. The reduction of the ratio seemed to be mainly due to this change. Moreover, 6-Keto-PGF1α tended to be decreased to a less degree and TXB2 to a higher degree in the group of patients with arteriosclerosis than in that of normal healthy subjects.
5) The βTG and PF-4 levels were significantly decreased as compared with the pretreatment values, in the arteriosclerosis group but no significant changes in these parameters were observed in normal healthy subjects.
6) There was no significant correlation between the serum aspirin concentration and platelet functions.
The results indicate that aspirin exerts a satisfactory effect as an antiplatelet drug when administered at 300mg once daily and additionally that its suppressive potency is within a constant limit. Thus, continuous long-term administration of aspirin is suggested to be possible.
