The aggregation and ATP release of placelet of normal subjects were measured by platelet lumi aggregometer. It was found that the aggregation curve induced by SJAMP at the concentration of 100 mg/L was a typical sec...The aggregation and ATP release of placelet of normal subjects were measured by platelet lumi aggregometer. It was found that the aggregation curve induced by SJAMP at the concentration of 100 mg/L was a typical second phase aggregation. There existed a certain lag between platelet aggregation and secretion. The secretion actually began slightly after the second phase of aggregation, suggesting that the second phase aggregation induced by SJAMP is not dependent upon the release of contents of dense granule alone. If platelets were incubated with cyclo oxygenase inhibitor, the second phase aggregation was inhibited and no ATP was released. The results indicated that the aggregation and release reaction induced by SJAMP were dependent upon the generation of prostaglandin endoperoxides and TXA 2 in normal subjects. The amount of ATP release was 0.69±0.22 nmol/10 8 platelets as stimulated with SJAMP (100 mg/L). But the amount of ATP release were 1.60±0.25 and 1.37±0.15 nmol/10 8 platelets when platelets were stimulated with ADP (5 μmol/L) and collagen (5 mg/L). The amount of ATP release induced by SJAMP was significantly lower than that of ADP and collagen. These findings indicated that SJAMP was a weaker agonist than ADP in terms of platelets release reaction.展开更多
Using the method of dual-wavelength measurement of platelet [Ca2+]i, and Fura-2 as the Ca2+ fluorophore probe, we measured the effect of acidic Mu-copolysaccharide from Sticopus Japonicus Selenka (SJAMP) on platelet [...Using the method of dual-wavelength measurement of platelet [Ca2+]i, and Fura-2 as the Ca2+ fluorophore probe, we measured the effect of acidic Mu-copolysaccharide from Sticopus Japonicus Selenka (SJAMP) on platelet [Ca2+]i. The results showed that the most significant increase in platelets [Ca2+]i was seen when the concentration of SJAMP was 100μg/ml and the elevation of normal platelet [Ca2+]i was 93. 96±10. 24 nmol/L (n = 10). In the presence of extracellular Ca2+(1 mmol/L), the magnitude of platelet [Ca2+]i response to SJAMP was increased and the [Ca2+]i, could reach 116. 72 + 10. 66 nmol/L (n= 10). On the other hand, the magnitude of increased platelet [Ca2+]i; induced by SJAMP was smaller and the duration of [Ca2+]i reaching the highest level was longer when compared with other platelet aggregation agents. In the mean time, if platelets were first incubated with cyclooxygenase inhibitor, the rise of [Ca2+]i evoked by SJAMP was inhibited. The results indicated that the mechanism of the rise of [Ca2+]i induced by SJAMP might be dependent upon the generation of prostaglandin endoperoxides and (or) TXA?.展开更多
文摘The aggregation and ATP release of placelet of normal subjects were measured by platelet lumi aggregometer. It was found that the aggregation curve induced by SJAMP at the concentration of 100 mg/L was a typical second phase aggregation. There existed a certain lag between platelet aggregation and secretion. The secretion actually began slightly after the second phase of aggregation, suggesting that the second phase aggregation induced by SJAMP is not dependent upon the release of contents of dense granule alone. If platelets were incubated with cyclo oxygenase inhibitor, the second phase aggregation was inhibited and no ATP was released. The results indicated that the aggregation and release reaction induced by SJAMP were dependent upon the generation of prostaglandin endoperoxides and TXA 2 in normal subjects. The amount of ATP release was 0.69±0.22 nmol/10 8 platelets as stimulated with SJAMP (100 mg/L). But the amount of ATP release were 1.60±0.25 and 1.37±0.15 nmol/10 8 platelets when platelets were stimulated with ADP (5 μmol/L) and collagen (5 mg/L). The amount of ATP release induced by SJAMP was significantly lower than that of ADP and collagen. These findings indicated that SJAMP was a weaker agonist than ADP in terms of platelets release reaction.
基金This project was supported by grant from the National Nature Science Foundation of China (No.39370322)
文摘Using the method of dual-wavelength measurement of platelet [Ca2+]i, and Fura-2 as the Ca2+ fluorophore probe, we measured the effect of acidic Mu-copolysaccharide from Sticopus Japonicus Selenka (SJAMP) on platelet [Ca2+]i. The results showed that the most significant increase in platelets [Ca2+]i was seen when the concentration of SJAMP was 100μg/ml and the elevation of normal platelet [Ca2+]i was 93. 96±10. 24 nmol/L (n = 10). In the presence of extracellular Ca2+(1 mmol/L), the magnitude of platelet [Ca2+]i response to SJAMP was increased and the [Ca2+]i, could reach 116. 72 + 10. 66 nmol/L (n= 10). On the other hand, the magnitude of increased platelet [Ca2+]i; induced by SJAMP was smaller and the duration of [Ca2+]i reaching the highest level was longer when compared with other platelet aggregation agents. In the mean time, if platelets were first incubated with cyclooxygenase inhibitor, the rise of [Ca2+]i evoked by SJAMP was inhibited. The results indicated that the mechanism of the rise of [Ca2+]i induced by SJAMP might be dependent upon the generation of prostaglandin endoperoxides and (or) TXA?.
