Biomaterial Database

The mechanism of fluoride-induced hypocalcaemia. 1994

A B Boink, and J Wemer, and J Meulenbelt, and H A Vaessen, and D J de Wildt

Laboratory of Toxicology, National Institute of Public Health and Environmental Protection, Bilthoven, The Netherlands.

1. Fluoride intoxication leads to sudden cardiac death which has been assumed to result from the accompanying severe hypocalcaemia. The aim of this study has been to investigate the suggestion that fluorapatite formation rather than CaF2 precipitation is responsible for this low calcium. 2. Measurements of free Ca2+ and F- ion concentrations in HEPES buffered solutions containing F-, Ca2+, and phosphate ions at different concentrations in the absence and presence of hydroxyapatite showed that the presence of hydroxyapatite enhanced the decrease of Ca2+ and F- concentration. 3. The ratio of Ca2+:F- clearance was 5:1 which is consistent with formation of fluorapatite. These results support the hypothesis that hydroxyapatite acts as a nucleation catalyst for fluorapatite formation and this process is responsible for the hypocalcaemia induced by fluoride intoxication. 4. The proposed mechanism explains also the metabolic acidosis which is frequently seen in cases of fluoride intoxication.

UI	MeSH Term	Description	Entries
D006996	Hypocalcemia	Reduction of the blood calcium below normal. Manifestations include hyperactive deep tendon reflexes, Chvostek's sign, muscle and abdominal cramps, and carpopedal spasm. (Dorland, 27th ed)	Hypocalcemias
D008297	Male		Males
D010710	Phosphates	Inorganic salts of phosphoric acid.	Inorganic Phosphate,Phosphates, Inorganic,Inorganic Phosphates,Orthophosphate,Phosphate,Phosphate, Inorganic
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D005459	Fluorides	Inorganic salts of hydrofluoric acid, HF, in which the fluorine atom is in the -1 oxidation state. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed) Sodium and stannous salts are commonly used in dentifrices.	Fluoride
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012969	Sodium Fluoride	A source of inorganic fluoride which is used topically to prevent dental caries.	Fluoristat,Ossin,Zymafluor,Fluoride, Sodium,Fluorides, Sodium,Fluoristats,Ossins,Sodium Fluorides,Zymafluors
D017208	Rats, Wistar	A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.	Wistar Rat,Rat, Wistar,Wistar Rats
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus