The effects of fluoridated water on rat urine and tissue cAMP levels

Male Wistar rats were fed a fluoride deficient diet (less than 0.5 parts/10(6) F), and either distilled water or fluoridated water (1.0 parts/10(6)). By week 3, the control group had urinary excretions of 106 +/- 5 nmol cAMP/day (mean +/- SEM) whereas the experimental group excreted 129 +/- 6 nmol cAMP/day. After 111 days, the control group excreted 270 +/- 26 nmol cAMP/day compared to 600 +/- 78 nmol cAMP/day for the experimental group. Body weight, food and water consumption, urine volume, and urinary creatinine and phosphate levels were not significantly different between the two groups. Tissue cAMP levels were determined after 4, 6 and 16 weeks. By week 4, the rats receiving the fluoridated water had significantly higher levels of cAMP in the liver (113 per cent) tibia (130 per cent), femur (89 per cent) and heart (35 per cent). At week 6, the liver (119 per cent), tibia (296 per cent), heart (168 per cent), kidney (73 per cent) and submandibular gland (27 per cent) had significantly higher levels of cAMP. By week 16, the liver, femur, kidney and submandibular gland continued to have elevated levels of cAMP. Liver glycolytic metabolites were determined after 6 weeks, and the results suggested a decrease in pyruvate kinase activity.