title: Aspects of carbonic anhydrase and carbonate content during mineralization of the rat enamel.
abstract: We examined carbonic anhydrase and carbonate content in developing dental enamel to clarify some problems in connection with the initial mineralization. Two-dimensional electrophoretic analysis showed that the type of carbonic anhydrase isoenzyme in developing enamel tissue was a low-activity form. A relatively high activity of carbonic anhydrase was detected in the developing enamel of rat lower incisors. We also determined that the content rate of carbonic anhydrase accounts for about 4% of the total matrix proteins of early developing enamel. A remarkable reduction of carbonic anhydrase activity occurred at the maturation stage, and then disappeared in the fully matured enamel. The carbonate content also decreased gradually, showing a parallel profile to that of carbonic anhydrase activity, from 3.5% to 1.9% in mineral phase. From the present study, we proposed that carbonic anhydrase in the initial site of mineralization may act as a trigger for the crystal nucleation by supplying the carbonate ions into the precursor mineral at the early stage of crystal development.
authors.affiliation: 1st Department of Oral Anatomy, School of Dentistry, Meikai University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kakei
authors.forename: H
authors.initials: H
authors.lastname: Nakahara
mesh_terms: D000818:Animals; D002113:Calcification, Physiologic; D002254:Carbonates / Q000032:analysis*; D002256:Carbonic Anhydrases / Q000032:analysis*; D003743:Dental Enamel / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D002254:Carbonates; D002256:Carbonic Anhydrases