Evaluation method of platelet aggregogram from viewpoint of reaction velocity and its application. Effect of nucleic acid relating substances to the platelet aggregation

Abstract

Since Born introduced the turbidometric method observing platelet aggregation, there have been many evaluations of platelet activity through the aggregogram.
We have recently found that the platelet aggregogram will yield a straight line following a log·log transformation of transmission, i. e.,
-log·log(T_∝/T)=at+c…(1)
The direction coefficient “a” of the regression equation (1) is considered the rate constant of the platelet aggregation, according to the following relationships,
-logT=mx+k…(2)
dx/dt=-a(x-x_∞)…(3)
and -log·log(T_∞/T₀)=at_r+c…(4)
where T, T_∞ and T₀ are the transmisson of at a given time t, of limiting value and of platelet rich plasma respectively, x and x_∞ are the number of platelets and its limiting value and a, c, m and k are constant. The t_r is the time interval of lag phase. Based on these relations, the aggregation in the aggregometer is felt the first order reaction and it was supported by the photomicroscopical observation through the sampling method. From this standpoint, authors used “a” and “t_r” to evaluate the platelet activity in the collagen induced reaction, while only “a” was used when ADP-induced aggregation was studied. In this paper, the effects of glycolytic metabolism and the effects of the nucleic acid relating substances are estimated with this method. High concentration of glucose, from 500mg/dl up to 2000mg/dl, acted as an inhibitor to collagen-induced aggregation, as shown in Fig. 1. Sodium fluoride, NaF, is known as an inhibitor of anerobic glycolytic metabolism as well as an inducer of relese reaction, as shown in Fig. 2. High concentration of glucose did not act as an inhibitor to the NaF-induced aggregation, while DBc-AMP and theophylline showed inhibitory action to the NaF aggregation, as shown in Fig. 3 and Fig. 4. DBc-AMP showed a remarkable inhibition to the collagen-induced aggregation, as shown in Fig. 5. This inhibition was more remarkable than that of c-AMP. AMP, Adenosine, DBc-GMP, and GMP showed an inhibitory action as well as theophylline. Inosine, Cytidine and Uridine showed on effect on “a”, but they showed a slight tendency to prolong “t_r”.