The presence of vesicles containing lactate dehydrogenase in the ameloblast layer of bovine enamel organ.
Ameloblast layers were removed from bovine enamel organs, followed by the separation of the extracellular matrix-vesicle fraction after collagenase digestion. Lactate dehydrogenase (LDH)-containing vesicles were found in that fraction. LDH in these vesicles did not result from cell lysis and vesicle capture during the preparation of the fraction. The isoenzyme pattern of LDH in LDH-containing vesicles was similar to that of cytosolic LDH of ameloblasts, suggesting the presence of a mechanism for specific uptake of cytosolic LDH during the in vivo formation of the vesicles. The existence of LDH-containing vesicles in enamel organ, where mineralization had been believed not to be initiated by matrix vesicles, suggests the possibility that LDH-containing vesicles have a specific function different from that of matrix vesicles.
Kitamura
C
C
Department of Operative Dentistry, Kyushu Dental College, Kitakyushu, Japan.
Terashita
M
M
Toyoshima
K
K
Noguchi
T
T
D000565:Ameloblasts / Q000201:enzymology* / Q000648:ultrastructure; D000818:Animals; D002415:Cats; D002498:Centrifugation; D005591:Chemical Fractionation; D003600:Cytosol / Q000201:enzymology; D003902:Detergents / Q000494:pharmacology; D004072:Digitonin / Q000494:pharmacology; D004658:Enamel Organ / Q000166:cytology / Q000201:enzymology*; D005109:Extracellular Matrix / Q000201:enzymology* / Q000648:ultrastructure; D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase / Q000032:analysis*; D017830:Octoxynol; D015388:Organelles / Q000201:enzymology; D011092:Polyethylene Glycols / Q000494:pharmacology; D012995:Solubility; D014617:Vacuoles / Q000201:enzymology
D003902:Detergents; D007527:Isoenzymes; D011092:Polyethylene Glycols; D017830:Octoxynol; D007770:L-Lactate Dehydrogenase; D004072:Digitonin