[Diurnal biological rhythms in the cells of granulation tissue in a liver injury]

Under study were the diurnal biological rhythms in 37 young mature male Wistar rats and in 44 young mature female Wistar rats in the cells of the granulation tissue (fibroblasts) 4 and 9 days respectively after injuring the liver. The animals were killed in groups every 4 h during 1 day, and in the second series--during 2 days. The diurnal rhythm was found in the mitotic activity. The first peak of mitoses was observed at midday and the second one--at midnight. The second peak may be absent. It has been shown autoradiographically that the maximum intensive synthesis of DNA took place at 8'clock a. m., i. e. 4th. before the appearance of the first maximum of mitoses. The most intensive synthesis of proteins and sulphated mucopolysaccharides in fibroblasts took place at 4 p. m.