Epithelial cell migration in the normal rat lens.
The purpose of the present study was to estimate the rate of the rat lens epithelium displacement. Twenty-four adult male rats were injected intraperitoneally with 18.5 kBq/g [3H] thymidine. Rats in groups of three were killed at the following times: after one hour, 3, 6, 9, 12, 15, 18 and 21 days. The enucleated eyes were fixed in formalin, embedded in paraffin, cut into 5 microns-thick sections, and subjected to autoradiography. The number of cells was counted, and the x-coordinate of each nucleus with three grains or more, and its grain content were recorded. Statistical analysis included analysis of variance and linear regression. The average lens diameter was 68 fields of 75 microns each (5.1 mm). Cell displacement was measured in two regions: Region A, the equatorial region, extending from field 0-20, and region B extending from field 20 to the lens center (field 34). Cells in region A are divided into two kinetic compartments, progenitor (P-cells) occupying fields 9-20, and non-proliferating (Q) cells occupying fields 0-8. Cells advanced from the P into the Q-compartment at a velocity of 21.8 microns/day. Cells did not move between field 20 and the lens center. These findings resemble kinetically renewing tissues, e.g. epidermis and crypt-villus in the gastrointestinal mucosa.
Pe'er
J
J
Department of Ophthalmology, Hadassah University Hospital, Jerusalem, Israel.
Muckarem
M
M
Zajicek
G
G
D000818:Animals; D002455:Cell Division; D002465:Cell Movement; D004847:Epithelial Cells; D007908:Lens, Crystalline / Q000166:cytology*; D008297:Male; D051381:Rats