Blood leucocyte enzyme activities I. Diurnal rhythm in normal individuals∗∗∗

Supported by MCRD Grant, 1972.

Abstract

The presence of a temporal order in living systems is manifested in biological rhythms. Attention was focused on the presence of diurnal and circadian rhythms. In view of the easy availability of leucocytes on the one hand and their involvement in numerous pathological conditions on the other, a study on the diurnal activity of six white blood cell (WBC) enzymes was performed in normal individuals. In one group of subjects the activities of four of the enzymes were measured twice a day for three consecutive days and in another group the enzyme activities were determined every 4 hrs for 24 hrs.

Diurnal variations in the total WBC number, as well as in the relative amounts of lymphocytes, granulocytes and monocytes were observed. Oscillation in the enzymatic activities demonstrated a nearly circadian rhythm. Since the enzymatic activities differ from day to day, it is plausible that the diurnal rhythm is part of a more complicated (weekly or monthly) oscillatory process.

Abstracting keywords:

• Diurnal rhythms
• enzymes
• leucocyte

Notes

Supported by MCRD Grant, 1972.

Dept of Human Genetics, Tel‐Aviv Univ. Med.School, Tel‐Aviv, Israel.

Inst. of Hematology, Tel‐Aviv Univ. Med. School and the Chaim Sheba Med. Center, Tel‐Hashomer, Israel (B. Ramot: Dept Head; F. Brok‐Simoni: Research Associate; F. Holtzman: Research Technician