[Effects of EDTPO on hard tissues in rats. 1. Comparison of histological changes produced by same molar of EDTPO, HEBP and EDTA].

Abstract

Ethylenediamine-N,N,N',N'-tetrakis (methylenephosphonic acid) (EDTPO) is a potent inhibitor of both formation and dissolution of hydroxyapatite crystals in vitro as well as 1-hydroxyethylidene-1, 1-bisphosphonic acid (HEBP). The purpose of this study was to compare with the biological effects of the same molar level of EDTPO, HEBP and ethylenediamintetraaceticacid (EDTA), prototype of EDTPO, on bone, incisor dentin and serum chemistry in young rats. HEBP at 8mg P/kg does chosen based on it's toxicity, and 16mg P/kg of EDTPO and 48mg/kg of EDTA which were identical molar level with 8mg P/kg of HEBP, were injected subcutaneously at once a day for 10 days. At the end of treatment period blood for chemical analysis, and tibia and mandibular for histological examination were taken. Results obtained were; 1) EDTPO and HEBP impaired the net weight gain during experimental period, by about 80% of final body weight in control group, but EDTA did not affect. 2) The biochemical findings of serum were as follows; calcium (Ca) level increased in EDTPO and HEBP group, and inorganic phosphorus (IP) level decreased in EDTPO and HEBP group when compared to control group, and changes of Ca and IP level in EDTPO group was more remarkable than those of HEBP group. Alkalie phosphatase level was decreased in EDTPO group, but increased in HEBP group compared to control group. There were no significant differences between EDTA group and control group, excepting for decrease of Ca level. 3) In histological aspects of the tibia, EDTPO and HEBP groups revealed enlargement of growth plates, being greater in EDTPO group than HEBP group, over the control group, and showed expanded hypertrophic zone of growth plates and wide osteoid seams in the metaphysis. EDTPO group also inhibited the calcification of dentin of mandibular incisor more strongly than HEBP group. From these data, it was indicated that EDTPO is more potent inhibitor of calcification than HEBP. Both of EDTPO and HEBP group, moreover, revealed enlargement of tibial metaphysis. These phenomena suggest that EDTPO also inhibits bone resorption as well as HEBP. EDTA group did not reveal any differences compared to control group.

• Authors: Y Tanaka, M Aizawa, T Masuhara
• Journal: Shigaku = Odontology; journal of Nihon Dental College (Shigaku) Vol. 77 Issue 2 Pg. 417-29 (Aug 1989) ISSN: 0029-8484 [Print] Japan
• PMID: 2518739 (Publication Type: English Abstract, Journal Article)

Chemical References

• Diphosphonates
• Organophosphorus Compounds
• (ethylenedinitrilo)-tetramethylenephosphonic acid
• Edetic Acid
• Etidronic Acid

Topics

• Animals
• Bone Resorption
• Calcification, Physiologic (drug effects)
• Diphosphonates (toxicity)
• Edetic Acid (toxicity)
• Etidronic Acid (toxicity)
• Growth Plate (drug effects)
• Mandible (drug effects)
• Molar (drug effects)
• Organophosphorus Compounds (toxicity)
• Rats
• Tibia (drug effects)