Circadian dynamics of cell composition of the thymus and lymph nodes in mice normally, under conditions of permanent illumination, and after melatonin injection.

摘要

The effect of melatonin on disturbed circadian variations in the lymphocyte subpopulation composition of the thymus and inguinal lymph nodes was studied in CBA mice exposed to constant illumination for 14 days. The desynchronizing effect of permanent illumination on the thymus consisted in disappearance of circadian variations in the total number of thymocytes, absolute count of thymocytes, absolute counts of CD8(+) and CD4(+) cells, and in inversion of changes in the absolute counts of CD4(+)8(+) cells from 15.00 to 20.00. In lymph nodes circadian variations in the percentage of CD4(+)+ lymphocytes disappeared, while absolute counts of CD4(+)8(+) and CD8(+) cells changed from 15.00 to 20.00. Melatonin restored circadian dynamics of some parameters mainly in the thymus.