SEX-RELATED AND AGE-RELATED DIFFERENCES IN PLATELET-FUNCTION IN-VITRO- INFLUENCE OF HEMATOCRIT

Even minor changes in the sodium citrate concentration of citrated pla sma from young probands due to diverse hematocrit values were found to affect platelet functional activity following in vitro stimulation. T here were no differences between men and women in the platelet aggrega tion and TXB2 production of young probands with similar hematocrit val ues. Platelets from elderly persons virtually failed to respond to suc h changes in plasma sodium citrate. Mechanisms of increased platelet a ctivity in the elderly are discussed. It is assumed that the age-relat ed differences are caused by a more pronounced platelet response even to lower plasma calcium levels in citrated plasma.