The Influence of Growth Hormone on Cell Proliferation in Odontogenic Epithelia by Bromodeoxyuridine Immunocytochemistry and Morphometry in the Lewis Dwarf Rat

Abstract

For investigation of how growth hormone affects tooth development, bromodeoxyuridine immunocytochemistry and morphometry were used for the study of cell proliferation in odontogenic epithelial cell layers. The number of cells in the S phase, as revealed by this technique, and in mitosis, were counted in Bouin's-perfused and paraffin-embedded undecalcified maxillary incisor enamel organs of normal rats, in growth-hormone-deficient dwarf rats, and in dwarf rats treated with growth hormone (66 μg/100 g body wt) twice daily for six days. Significantly fewer labeled nuclei, unlabeled nuclei, and total nuclei of various odontogenic epithelia were found in dwarf rats, but in dwarf rats treated with growth hormone, numbers of labeled nuclei equivalent to normal were found in the internal enamel epithelium, stratum intermedium, and Hertwig root sheath. Moreover, the mitotic index for pre-ameloblasts was 1.64 in normal rats, 0.92 for dwarf rats, and 1.66 for growth-hormone-treated dwarf rats (SD, 0.10). Other parameters-such as the labeling index and the ratio of positive to negative nuclei-were similarly related to GH status. Thus, growth hormone may play a role in the proliferation of the odontogenic epithelia in the rat.

Get full access to this article

View all access options for this article.

References

Barnard R. , Ng KW , Martin TJ , Waters MJ (1991). Growth hormone (GH) receptors in clonal osteoblast-like cells mediate a mitogenic response to growth hormone. Endocrinol 128:1459-1464.

Barnard R. , Haynes KM , Werther GA , Waters MJ (1988). The ontogeny of growth hormone receptors in the rabbit tibia. Endocrinol 122 :2562-2569.

Casasco A. , Calligaro A. , Marchetti C. , Poggi P. , Brugnatelli S. , Danova D. , et al. (1989). Immunocytochemical detection of proliferating cells in the rat tooth germ by monoclonal antibodies against 5'-Bromo-2'-Deoxyuridine . Arch Oral Biol 34:65-69.

Charlton HM , Clark RG , Robinson CAF , Porter Goff AE , Cox BS , Bugnon C. , et al. (1988). Growth hormone-deficient dwarfism in the rat: a new mutation. J Endocrinol 119:51-58.

Chiba M. (1965). Cellular proliferation in the tooth germ of the rat incisor. Arch Oral Biol 10:707-718.

Chiba M. , Nakagawa K. , Mimura T. (1967). DNA synthesis and cell division cycle at the base of the maxillary incisor tooth of the young rat. Arch Oral Biol 12:865-876.

Daughaday WH , Rotwein P. (1989). Insulin-like growth factor I & II peptide, RNA and gene structures, serum and tissue concentration. Endocr Rev 10:68-91.

Gasser RF , Scheving LE , Pauly JE (1972). Circadian rhythms in the cell division rate of inner enamel epithelium and in the uptake of 3H thymidine by the root tip of rat incisor. J Dent Res 51:740-746.

Goldspink DFL , Goldberg AL (1975). Influence of pituitary growth hormone on DNA synthesis in rat tissues. Am J Physiol 228:302-309.

10.

Green H. , Morikawa M. , Nixon T. (1985). A dual effector theory of growth hormone action . Differentiation 29:195-198.

11.

Hunt AM , Paynter KJ (1963). The role of cells of the stratum intermedium in the development of the guinea pig molar. Arch Oral Biol 8:65-78.

12.

Isaksson OGP , Lindahl A. , Nilsson A. , Isgaard J. (1987). Mechanism of the stimulatory effect of growth hormone on longitudinal bone growth. Endocrine Rev 8:426-454.

13.

Morgan K. , Darzynkiewicz Z. , Staiano-Coico L. , Melamed MR (1985). Detection of 5 bromodeoxyuridine (BrdUrd) incorporation by monoclonal antibodies: Role of the DNA denaturation step. J Histochem Cytochem 33:821-827.

14.

Nilsson A. , Isgaard J. , Lindahl A. , Dahlstrom A. , Skottner A. , Isaksson OGP (1986). Regulation by growth hormone of number of chondrocytes containing IGF-I in rat growth plate. Science 233:571-574.

15.

Ruch JV ( 1990). Patterned distribution of differentiating dental cells: facts and hypotheses. J Biol Buccale 18:91-98.

16.

Slootweg MC , Van Buul-Offers SC , Herrmann-Erlee MPM , Van der Meer JM , Duursma SA (1988). Growth hormone is mitogenic for fetal mouse osteoblasts but not for undifferentiated bone cells. Endocrinol 16 :R11-R13.

17.

Smith CE , Warshawsky H. (1975). Cellular renewal in the enamel organ and the odontoblast layer of the rat incisor as followed by radioautography using 3H-thymidine . Anat Rec 183:523-562.

18.

Smith CE , Warshawsky H. (1977). Quantitative analysis of cell turnover in the enamel organ of the rat incisor. Anat Rec 187:63-98.

19.

Sugimara H. , Hattori T. , Fukuda M. (1986). Immunohistochemical detection of bromodeoxyuridine in formalin-fixed tissues. Histochemistry 85 :193-195.

20.

Waters MJ , Lobie PE , Barnard R. , Lim L. , Hamlin G. , Breipohl W. , et al. (1992). Hormone receptors and growth. In: Rakey K , Bek K , Banden M , editors. Animal health and production in the twenty-first century. Melbourne (Australia): CSIRO Information Service Unit (in press).

21.

Waters MJ , Lobie PE , Gobius KS , Rowlinson SR , Garcia-Aragon J. , Zhang CZ , et al. (1991). Growth hormone receptors-Recent developments . Proc Endocr Soc Aust 34:S145-S149.

22.

Wroblewski J. , Engstrom M. , Skottner A. , Madsen K. , Friberg U. (1987). Subcellular location of IGF-I in chondrocytes from rat rib growth plate. Acta Endocrinol (Cobenh) 115:37.

23.

Young RW (1962). Cell proliferation and specialization during endochondral osteogenesis. J Cell Biol 14:357-370.

24.

Zajicek G. , Bar-Lev M. (1971). Kinetics of the inner enamel epithelium in the adult rat incisor. 1. Experimental Results. Cell Tissue Kinet 4:155-162.

25.

Zajicek G. , Michaeli Y. , Weinreb MM (1972). Kinetics of the inner enamel epithelium in the adult rat incisor during accelerated eruption. Cell Tissue Kinet 5:35-39.

26.

Zajicek G. , Michaeli Y. , Regev J. (1979). On the progenitor cell migration velocity. Cell Tissue Kinet 12:435-460.

27.

Zhang CZ , Young WG , Waters MJ (1992a). Immunocytochemical localization of growth hormone receptor in rat maxillary teeth. Arch Oral Biol 37:77-84.

28.

Zhang CZ , Young WG , Li H. , Garcia-Aragon J. , Clayden AM , Waters MJ (1992b). Expression of growth hormone receptor by immunocytochemistry in rat molar root formation and alveolar bone remodelling. Calcif Tissue Int 50:541-546.