Aggregation of human platelets by acidic mucopolysaccharide extracted from Stichopus japonicus Selenka.

The acidic mucopolysaccharide extracted from sea cucumber (Stichopus japonicus Selenka) (SJAMP) has been shown to cause platelets to aggregate. Using citrated platelet-rich plasma (PRP), washed platelets and formaldehyde-fixed platelets from humans, we investigated the effects of platelet inhibitors and various plasmas and their fractions on SJAMP-induced platelet aggregation. It was found that the lowest concentration of SJAMP required for the aggregation of human platelets was about 0.4 micrograms/ml and the magnitude of aggregation induced by SJAMP was concentration dependent. The platelets were aggregated by SJAMP at 10 micrograms/ml in 25 out of 28 (89%) normal subjects tested. Platelet inhibitors such as PGE1, aspirin, indomethacin, apyrase, antimycin, 2-deoxy-D-glucose and EDTA inhibited by 70 to 100% the aggregation induced by SJAMP. Washed platelets alone were not aggregated by SJAMP. In the presence of fibrinogen, washed platelets were aggregated by SJAMP but formaldehyde-fixed platelets were not. These data indicate that the SJAMP-induced human platelet aggregation requires extracellular calcium, fibrinogen, and energy metabolism. The second phase of aggregation is dependent upon the release of ADP, and cyclooxygenase pathway.