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In this study the authors developed new technics of study of duodenal absorption of calcium in rats: atomic absorption spectrophotometry, and dialysis to equilibrium. We considered that the main factors necessary for evaluation of duodenal absorption of calcium are the serum calcium, the calcium and alkaline phosphatase present in the duodenal cells and the calcium-binding proteins. The authors demonstrate that these factors are highest in rats treated with 25 OHD3 and norandrostenolone decanoate, than in control rats. In rats treated with diphosphonate, on the contrary, they obtained a reduction in the values of calcium and alkaline phosphatase contained in the duodenal cells.

In a first stage, the authors have evaluated the relationship between plasma calcitonin and urinary serotonin in patients presenting a chronic pathology, mostly of respiratory nature. The results have demonstrated that plasma calcitonin and urinary elimination of serotonin were increased (p less than 0.05) in patients presenting a chronic pathology, compared to 16 healthy patients of the same age and sex. In a second stage, the authors have evaluated the variations of urinary serotonin 24 hours after injection of 100 U MRC of calcitonin from salmon, in the same patients. The results showed (p less than 0.001) an increase of urinary serotonin at 24 hours. This increase is not observed after injection of eel or human calcitonin. The effect of the various calcitonin on serotonin metabolism is discussed.

In this paper, the authors discuss the variations in the quantity of spongy bone in rats of the same sex, same age and same weight subjected to a normocalcic diet, a hypocalcic diet or a hypocalcic diet plus synthetic anabolic agent. In the rats subjected to a hypocalcic diet, there is a statistically significant reduction in the quantity of spongy bone, in comparison to that of the other two groups. In other words, the hypocalcic diet led to a rarefying osteopathy, which was partially prevented by the use of synthetic anabolic agents. the authors also observed that the rarefying osteopathy was more intense in the distal epiphysis of the femur than in the neck of the femur. If this feature is confirmed in man, it would constitute a precious aid to the early detection of osteoporosis.

Prevention of the experimental bone rarefaction which occurs in rats put on a low calcium diet was attempted by using salmon calcitonin and 25 hydroxyvitamin D given with a similar regimen to that used in human disease. Results were compared with the previously reported effects of synthetic anabolic steroids. Statistical analysis was carried out on measurements of cancellous bone mass. No statistically significant increase in the femoral trabecular bone volume occurred in rats put on an hypocalcemic diet plus treatment by calcitonin and vitamin D whereas such an increase had been noted when anabolic steroids were used. Measurement of the trabecular bone volume of proximal and distal epiphyses demonstrated a statistically significant difference between rats on a hypocalcemic diet treated by 25-OH-D3 and rats treated by calcitonin or controls on a normal diet. In rats on a normal diet, 25 hydroxyvitamin D led to an increase in bone mass which did not reach statistical significance but is probably explained by improvement in calcium intestinal absorption.