[The chronobiology of inflammation]

The inflammatory reaction is characterized by a multifrequency time structure with prominent circadian, ultradian and infradian rhythms in cell proliferation and cell function. The circulating blood cells show highly reproducible circadian rhythms in human and in animals. Daily fluctuations of concentrations of haematologic chemical and endocrinological parameters are described. Circannual variations of several hematologic parameters are presented. Chronobiological studies of plasma exudation in carrageenan paw oedema show a circadian and a circannual rhythm. Daily and annual changes in migration of polymorphonuclear leucocyte produced by BCG are studied in mice. Differences in response are observed in adrenalectomized and castrated animals. The susceptibility of cells and tissues at different stages of their circadian or circannual rhythms lead to the development of a chronotherapy of inflammation.