EFFECT OF EHDP (1-HYDROXYETHANE-1, 1-DIPHOSPHONATE) ON RABBIT'S DENTINE CALCIFICATION FIGURES.

Abstract

The effects of EHDP on dentine calcification figures in rabbits were examined by the lead acetate time marking method. The following results were obtained.
1) It was confirmed by hematoxylin staining of the decalcified sections, X-ray analysis and microradiograms of the undecalcified sections and image analysis that EHDP causes hypocalcification in dentine calcification figures. The minimum dose of subcutaneous injection of 3 5 mg/kg (0.751.25 mgP/kg) produced the hypocalcifications and the degree of hypocalcification was strengthened in proportion to the dose.
2) Subcutaneous injection of EHDP 60 mg/kg (14.9 mgP/kg) each day for seven consecutive days caused EHDP rickety rats. Hypocalcification dentine is formed within the administration period, and not only the growth rate of teeth but also the development of bone are decreased.
3) One-hour injection into the arteria maxillaris or the arteria thyroidea caused hypocalcification dentine on the arterial infusion side at only 5 mg/kg, and strong formation on the same side and opposite side at 10 mg/kg and 30mg/kg. However, there were no specific changes in the thyroid tissues.
4) A 30 mg/kg subcutaneous injection did not affect serum Ca, Ca²⁺, P or PTH concentrations. It is conjectured that the concentration of EHDP in the blood is related to the dentine calcification figures.
5) From these results, the disturbance in dentine calcification that results from infusion at above doses can be conjectured to be related to the local action produced by the dentine formative function of EHDP.