Seasonal variation of the phagocytic activity of the reticulo-endothelial system

Abstract

Observation of the phagocytic activity of the reticulo-endothelial system in the healthy male albino mouse extending over 24 months showed a significant seasonal variation. This was found to range from a high level in the summer to a low one in the winter. The degree of variation was found to be constant for particular seasons in succeeding years. Assessment of phagocytic activity was made by measuring the rate of absorption of colloidal carbon from the blood stream (Halpern, Benacerraf and Biozzi, 1953). The causes of the variation are attributed to environmental factors and the individual mechanisms are discussed. A monthly correction factor is suggested so that investigations of phagocytic activity at different times of the year may be compared. An extension of the correction factor is proposed so that the variations in phagocytic activity produced by various agents can be related to a standard value.