A Study of Effects of 2A-1-1 on Platelet Function in Hypertension Patients.

Objective To study the effects of 2A-1-1, a purified component from Panax notoginsengs which is considered to be a blocker of ROC (Receptor-operated Ca²⁺ channel), on platelet aggregation in hypertension patients with Nifedipine and 1-{β-[3-(4-methoxyphenyl) propoxy]- 4-methoxyphenethyl}- 1H - imidazole hydrochloride (SK and F96365) in contrast.

Methods Platelet rich plasma (PRP) was made in routine way from venous blood samples which taken from 30 essential hypertension patients and 30 normal people. PRP was incubated with different concentrations of 2A-1-1, Nifedipine and SK&F96365 for 3 minutes. Therefore, maximal platelet aggregation rate (PAG_max) induced by ADP had been measured on TYXN-91 aggregometer.

Results 1. PAG_max in essential hypertension group was 88.48±5.36%, higher than that in normal group which was 67.54±8.46%( P<0.01). 2. Nifedipine (10μmol/L and 20μmol/L) had no effect on PAG_max in neither essential hypertension group nor normal group( P>10;0.05). 3. 2.5μmol/L, 5μmol/L, 10μmol/L and 20μmol/L SK&F96365 could reduce the PAG_max in essential hypertension group by 14.32%) 17.9%) 30.26%) 78.23% respectively; 5μmol/L, 10μmol/L and 20μmol/L SK&F96365 could reduce the PAG_max in normal group by 21.57%) 22.85%) 59.38% respectively. 4. 2.5μmol/L, 5μmol/L, 10μmol/L and 20μmol/L 2A-1-1 could reduce the PAG_max in essential hypertension group by 24.83%) 27.56%) 48.73%) 92.77% respectively; 5μmol/L, 10μmol/L, 20 μmol/L 2A-1-1 could reduce the PAG_max in normal group by 47.06%) 53.47%)71.52% respectively.

Conclusions 1. PAG_max in essential hypertension patients is higher than normal people remarkably, suggesting that the high reactive status of platelets is an important factor for the development of thrombus in hypertension patients.2. Nifedipine has no effects on PAG_max, therefore it can not inhibit platelet aggregation.3.SK and F96365 can reduce the platelet aggregation.4. 2A-1-1 can inhibit platelet aggregation, therefore, it has the definite effect of anti-platelet.