It is possible to stimulate intestinal calcium absorption during experimental chronic renal failure.

To explore the assumption on the functional inadequacy of renal alternative vitamin D synthesis during chronic renal failure, 50 subtotally-nephrectomized rats were treated with dihydrotachysterol, androgens, estrogens or androgens + estrogens. Fractional duodenal calcium absorption and calcium-binding protein content of intestinal mucosa were determined. Fractional duodenal calcium absorption was significantly decreased in uremic rats (6.61 +/- 1.64%). Dihydrotachysterol or androgen + estrogen administration lead to 3-fold increase in fractional duodenal calcium absorption, accompanied by the enhancement in calcium-binding protein content of mucosal layer. It is concluded that it is possible to stimulate intestinal calcium absorption during experimental chronic renal failure, probably via the rehabilitation of 1,25(OH)2D2 production.