[The internal variability of the mesothelium during regeneration following trauma applied at various times of the day].

A quantitative investigation of the mitotic activity (MA) dynamics, size of the cells, amount of their mutual contacts (as an index of the epithelial layer regulation) and amount of nucleoli in the nuclei of mesothelium after a trauma, performed at 9 a.m. and at 9 p.m. has been carried out. The investigation lasted for 96 h. According to statistically significant differences two zones are revealed: a nearer and a remote one. Changeability of mesothelium increases in both zones, but it is greater manifested in the nearer zone. MA dynamics in both zones demonstrates a quick growing and a similarly quick drop, except the remote zone after the morning operation, where MA decreases slower. Amount of the cells, whose nuclei contain more nucleoli than in the norm, increases before the development of the MA waves. MA increase is accompanied with decreasing size of the cells. Normalization of MA and size of the cells occur approximately simultaneously. This process is more manifested after the morning operation, and after the evening one, normalization of these signs, during the time of observation, is reached only in the remote zone. Disorganization of mesothelium, as a tissue system, precedes the MA increase. A significant difference of this sign from the control takes place only in the nearer zone after the morning operation. As a whole, the changeability of mesothelium is more manifested after the morning operation.