Abstract
For an analysis of relationship between membrane physicochemical properties and functions of platelets, aggregability, electrophoretic mobility, sialic acid amount and membrane glycoproteins were measured for platelets from 21 healthy aged males, 14 prostatic hypertrophy patients, 10 males with stomach or lung cancer, 2 prostatic cancer patients, 16 prostatic cancer patients on estrogen (stilbesterol diphosphate 300mg/day) and 15 similar patients on aspirin 330mg/day. Prostatic cancer patients on estrogen and stomach or lung cancer patients had significantly higher electrophoretic mobility than control. A good linear correlation was found between sialic acid amount and electrophoretic mobility of platelets (r=0.950, p<0.001). Platelet electrophoretic mobility had negative correlations with primary aggregation induced by adrenaline and by ADP, respectively, but it had no correlation either with secondary aggregation or with maximal aggregation. Treatment of rabbit platelets with increasing doses of neuraminidase resulted in increasing aggregation associated with decrease in electrophoretic mobility. Thus, surface negative charge seems to have the role to inhibit primary aggregation. Surface negative charge was influenced with composition of membrane glycoproteins, estrogen and changes in population of platelets. In addition, aspirin increased surface negative charge without the effect on sialic acid. Membrane glycoprotein patterns for prostatic cancer on estrogen indicated a significantly lower relative percentage of GP I and higher GP IV. A positive correlation was present between relative amount of GP II and intensity of primary aggregation induced by ADP. These results suggest that membrane physicochemical properties of platelets may affect their function.
