Platelet subpopulations in adult and geriatric males.

In this study, the authors wanted to investigate the volume, density, and percentage of three platelet subpopulations present in adult and geriatric males. Ninety subjects, between the ages of 20 and 40, were chosen for the adult group and 50 subjects, all older than age 70, were used for the geriatric group. The platelet subpopulations were separated with discontinuous gradients of Percoll. The results obtained from the three platelet subpopulations--low, intermediate, and high density--show different volumes and percentages in both the groups studied. From the information that larger platelets can be expected to have a longer life span, it was possible to hypothesize that platelets found in geriatric males have a reduced average life span. It is also clear that platelets exist that have similar volumes but different densities.