Cholesterol in the distal portions of differentiating and fully differentiated rat odontoblasts observed by freeze-fracture.
Freeze-fracture replicas of rat molar tooth germs in conjunction with the 3-beta-hydroxysterol marker filipin were used to study the distribution of cholesterol in the distal portions of odontoblast plasma membrane. Filipin-sterol deformations (interactions) appeared as clusters interspersed with deformation-free regions on the distal plasma membrane of early differentiating odontoblasts. In fully differentiated odontoblasts, the whole distal membrane, including the process, was occupied by packed deformations with no free regions. It seems that early developing odontoblasts are poorer in cholesterol than the fully differentiated cells. As the content and/or distribution of 3-beta-hydroxysterols (cholesterol) is known to influence membrane fluidity, the low cholesterol content of early differentiating odontoblasts might be related to the fluidity required for the budding off of matrix vesicles.
Franklin
D L
DL
Department of Child Health, University of Leeds, School of Dentistry, England.
Arana-Chavez
V E
VE
Katchburian
E
E
D000818:Animals; D015415:Biomarkers; D002454:Cell Differentiation; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D002784:Cholesterol / Q000378:metabolism*; D005372:Filipin; D005614:Freeze Fracturing; D008560:Membrane Fluidity; D008963:Molar; D009804:Odontoblasts / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016628:Replica Techniques; D014083:Tooth Germ / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D014617:Vacuoles / Q000378:metabolism / Q000648:ultrastructure
D015415:Biomarkers; D005372:Filipin; D002784:Cholesterol