Histological and Biochemical Observations of Developing Enameloid of the Sea Bream

Abstract

In order to study changes in the enameloid matrix of the Sea Bream during the course of its development, we selected the developmental tooth germs of this fish as representative of three different developmental stages: "chalk-like", "cheese-like", and "soft" enameloid. The protein, calcium, and phosphate contents of each sample were analyzed. The changes of the total protein content in each sample suggest that a major part of the proteins decreased during maturation, although newly formed enameloid of the Sea Bream contains collagen and noncollagenous proteins. The existence of proteolytic activity was examined by placement of undemineralized cryostat sections of unfixed tooth germs on exposed and processed photographic films and then incubation for 30 min in a water-saturated atmosphere at 37°C. Proteolytic activity could be detected in the enameloid matrix, which appeared to be in a "cheese-like" stage. It is suggested that proteolytic enzymes play an important role in the removal of proteins during the maturation of enameloid, although the detailed mechanism of the process is still obscure.

Get full access to this article

View all access options for this article.

References

Adams, C.M. and Tuqan, N.A. (1961): The Histochemical Demonstration of Proteinase by a Gelatin-Silver Film Substrate, J Histochem Cytochem 9:422-469.

Burgess, R.C. and MacLaren, C. (1965): Proteins in Developing Bovine Enamel. In: Tooth Enamel II, M.V. Stack and R.W. Feamhead , Eds., Bristol: John Wright & Sons Ltd, pp. 74-82.

Connerty, H.T. and Briggs, A.R. (1966): Determination of Serum Calcium by Means of Orthocresolphathalein Complex-one, J Clin Pathol 45:290-296.

Fiske, C.H. and Subbarow, Y. (1929): Phosphocreatin, J Biol Chem 81:629-679.

Fukae, M. and Shimizu, M. (1974): Studies on the Proteins of Developing Bovine Enamel , Arch Oral Biol 19:381-386.

Fukae, M. ; Tanabe, T. ; and Shimizu, M. (1977): Proteolytic Enzyme Activity in Porcine Immature Enamel, Tsurumi U Dent J 3:15-17.

Karnovsky, M.J. (1965): A Formaldehyde-Glutaraldehyde Fixative of High Osmolarity for Use in Electron Microscopy, J Cell Biol 27:137a-138a.

Poole, D.F.G. (1967): Enameloid and Enamel in Recent Vertebrates. In: Structural and Chemical Organization of Teeth, Vol. 1, A.E.W. Miles , Ed., New York: Academic Press, pp. 111-149.

Prostak, K. and Skobe, Z. (1986): Ultrastructure of the Dental Epithelium during Enameloid Mineralization in a Teleost Fish, Cichlasoma cyanoguttatum, Arch Oral Biol 31:73-85.

10.

Shellis, R.P. (1975): A Histological and Histochemical Study of the Matrices of Enameloid and Dentine in Teleost Fishes, Arch Oral Biol 20:183-187.

11.

Shellis, R.P. (1981): Comparative Development of Dental Tissues. In: A Companion to Dental Studies, Vol. 1, Book 2, Dental Anatomy and Embryology, J.W. Osborn , Ed., London, England: Blackwell Scientific Publications , pp. 155-157.

12.

Shellis, R.P. and Miles, A.E.W. (1974): Autoradiographic Study of the Formation of Enameloid and Dentine Matrices in Teleost Fishes Using Tritiated Amino Acids, Proc R Soc Lond B 185 :51-72.

13.

Shellis, R.P. and Miles, A.E.W. (1976): Observations with the Electron Microscope on Enameloid Formation in the Common Eel (Anguilla anguilla: Teleostei), Proc R Soc Lond B 194:253-269.

14.

Shimizu, M. ; Tanabe, T. ; and Fukae, M. (1979): Proteolytic Enzyme in Porcine Immature Enamel , J Dent Res 58(B):782-789.

15.

Suga, S. (1970): Histochemical Observation of Proteolytic Enzyme Activity in the Developing Dental Hard Tissues of the Rat, Arch Oral Biol 15:555-558.