Neutron-activation measurement of metabolic activity of sodium in the human hand.

Turnover of sodium in the human hand was studied by neutron activation. One hand of each subject was irradiated with a 1.5-rad dose of partially thermalized fast neutrons. The activity of 24Na was measured at intervals from 3 min to 48 hr after irradiation. The loss of sodium from the hand during this period can be described either by two exponentials or by a single power function. The latter description involves only two disposable factors compared with four in the former. The rate of loss of sodium was found, on the average, to be greater in patients suffering from bone disease than in normal subjects. Neutron activation is a powerful method for studying sodium turnover because the sodium atoms are labeled simultaneously and with equal probability, regardless of the turnover time of individual bodily compartments.