[Proliferative activity and cell differentiation during the period of intensive growth of the iris, ciliary body and pupillary sphincter in rats].

The duration of the cell cycle in the sphincter pupillae and in the inner and outer neuroepithelia of the iris and ciliary body was studied. The four-day old rats were injected H3-thymidine and three-day old animals were administered H3-dopa to be processed for autoradiography. Cells of sphincter and of both neuroepithelia of the iris have the doubling time of 9.