Effects of Experimental Fluoride Poisoning on Al-P Activity and cAMP Level in Plasma and Bone in Rats

Studies with Pair Feeding Controls

Abstract

Alkaline phosphatase (Al-P) activity and 3′, 5′ cyclic AMP (cAMP) levels in plasma and bone in rats experimentally poisoned with fluoride (F) were determined and compared with the results of pair feeding.
1) As F doses increased, the uneaten food in F intake groups increased. This was about 30% in 4mg F groups and about 50% in 6mg F groups. Body weight was lower in F intake groups than in control groups. The change in body weight in pair feeding control groups showed the same pattern as in F intake groups.
2) Al-P activity in plasma was significantly greater in 4mg F groups and 6mg F groups than in pair feeding control groups (p<0.05 and p<0.01, respectively).
3) Al-P activity in bone appeared to increase in F intake groups compared to control groups. Al-P activity in bone was lower in pair feeding groups used as controls to 4mg F groups or 6 mg F groups than in the respective F intake groups.
4) Cyclic AMP level in plasma was higher in F intake groups than in control groups. There was significant difference between control groups and both 4mg F and 6mg F groups (p<0.01). Plasma cAMP level in pair feeding control groups was about same level as control groups.
5) Cyclic AMP level in bone tended to be higher in F intake groups than in control groups. There was a significant difference between control groups and 4mg F groups (p<0.01). Bone cAMP level in pair feeding groups used as controls to 4mg F or 6mg F groups was similar to the level in control groups.
6) F concentration in both plasma and bone increased in proportion to the dose of F. There was a significant positive correlation between Al-P activity and F concentration.