Fluoride effects in alkaline phosphatase in rats chronically exposed

Objectives: The objective of the study was to comparatively evaluate the fluoride (F) concentration in kidney, liver and plasma, and possible alterations in the activity of alkaline phosphatase in plasma and liver of rats chronically exposed to F.

Methods: Twenty four male Wistar rats were used, divided into 4 groups (n=6) which differed according to the F concentration in the drinking water that the animals received for 60 days. Group I received deionized water, while groups II, III and IV received water containing 5, 15 or 50 ppm F, respectively. After the experimental period, animals were euthanized and their plasma, kidney and liver were collected. F in kidney, liver and plasma was analyzed with the electrode. Activity of alkaline phosphatase in plasma and liver was assayed colorimetrically. Data were analyzed by ANOVA (p<0.05).

Results: F concentration in plasma and the organs increased according to the increase in drinking water F concentration. F concentrations in plasma and organs were not significantly different between groups I and II. F concentrations in the tissues were significantly different when comparing groups I and IV. The weight of the animals' organs decreased and the activity of alkaline phosphatase in plasma and liver increased in groups III and IV when compared to Group I.

Conclusions: F chronically administered to rats in high concentrations in the drinking water can promote a decrease in the weight of kidney and liver, as well as an increase in the activity of alkaline phosphatase in liver and plasma.