Three-dimensional presentation of cell migration in the periodontal ligament of the rat incisor.
The progenitor compartments and cell migration were examined in the tooth-related periodontal ligament (t-PDL) of rat incisors. A pulse injection of 3H-Tdr was administered to 15 rats (200 gm each) and the animals were killed in groups of five, at 1 hr and at 1 and 2 weeks after injection. Three-dimensional analysis of cell counts and labeling index demonstrated the existence of two progenitor compartments (PC). The apical PC (responsible for 70% of synthesizing cells) was concentrated in the apical 5 mm of the t-PDL. The paracemental PC (30% of synthesizing cells) was located along and around the cementum, occupying 24 micron of the t-PDL. The cells from the apical PC migrated incisally at a rate of 6 mm/week, which is a rate similar to that of tooth eruption. The cells from the paracemental PC moved in a transverse direction toward either bone or cementum at the much slower rate of 16 micron/week.
Department of Anatomy, Hebrew University--Hadassah Dental School, Jerusalem, Israel.
Y
Y
Michaeli
S
S
Steigman
A
A
Barad
M
M
Weinreb
D000818:Animals; D002452:Cell Count; D002465:Cell Movement; D005260:Female; D007180:Incisor; D010513:Periodontal Ligament / Q000166:cytology*; D051381:Rats