Abstract
It was reported by Sobel and coworkers that rickets developed in young rats when carbonate of the normal synthetic diet was replaced by strontium carbonate, and that this strontium rickets failed to respond to vitamin D. It might be postulated that the changes observed by Sobel and coworkers had resulted from the feeding of a low P diet and had not been due to the action of strontium.
In this experiment, 2% strontium carbonate was substituted for calium in the normal synthetic diet and was fed to young rats.
Young male rats were divided into 3 groups. The first group received the normal diet. The second received strontium diet lacking in vitamin D. The third group received the normal diet followed by vitamin D 11 days after.All animals were sacrificed after 25 days. After 14 days, the roentgenograms of strontium-fed rats showed charactristic rachitogenic changes in the epidiaphyseal region of tibiae and femora. The rats in the first group weighed 53 gm at the beginning of the treatment and 32 gm after 25 days, while the second and third groups gained to 82 and 73 gm respectively at the time of sacrifice. The ash contents of tibiae in the second and third groups Showed 38 and 40% respectively and represented the inhibitory action of strontium on calcification when compared with the first group whsch contained 53% ash.
The average citrate content of the femora of rats in the second group was 2.8 mg/g and it differs significantly from the first group which contained 4.7 mg/g of citrate. In the third group, the citrate content was 3.6 mg/g, but there was no significant difference from the second group. More than twice as much hexosamine, which represented indirectly the state of acid mucopolysaccharide, was observed in the femora of the second and third groups in comparion with that of the first group.
