Effects of synthesized hard water and of cadmium in the drinking water upon lipid metabolism and cholelithiasis in rabbits.

Rabbits were fed a purified ration known to result in cholelithiasis and alterations in lipid metabolism. During a 12-week experimental period, either synthesized hard water (500 mg of Ca/L and 100 mg of Mg/L) or deionized distilled water were available as drinking water, and half of each of these groups of rabbits were also given 5 mg of Cd/L of water. Hair samples taken at the beginning and end of the experiment revealed an increase in the Ca concentration in rabbits given hard water, but no increase in Cd in rabbits given this element in the water. Cadmium in the drinking water resulted in accumulations of this element in liver and kidneys, and water hardness did not influence the amount of accumulation. Liver cholesterol concentrations and the severity of cholelithiasis were less in rabbits given Cd. The hard water administration resulted in lower liver cholesterol concentrations and less cholelithiasis. These results indicate that hard water does not reduce cardiovascular disease frequency by lessening Cd accumulation, but may affect cholesterol metabolism.