Lithium effects on magnesium, calcium, and phosphate metabolism in rats.

Rats were treated with lithium chloride for 8 weeks. At the last day of lithium administration, the animals were given radioactive calcium, magnesium, and phosphate. Electrolyte content and radioactivity were determined in serum, bone, muscle, liver and brain. Lithium led to an increase of inorganic phosphate in muscle and a decrease in serum. Uptake of radioactive phosphate was increased in muscle and liver but reduced in bone. The amount of magnesium in muscle and serum was increased in the lithium-treated rats, whereas the uptake of radioactive magnesium into bone was decreased. Uptake of radioactive calcium into bone was reduced, and radioactive calcium in serum was increased after lithium.