Effect of renal insufficiency on gastrointestinal transport of calcium

Abstract

Chronic experimental renal insufficiency induced by subtotal nephrectomy decreased the ability of the isolated rat duodenal gut sac to transport calcium against a chemical gradient. The defect in intestinal transport was not reproduced by metabolic acidosis, uremia of short duration, or addition of urea to the ambient solution bathing the gut sac. The transport of calcium by the intestine of uremic rats was increased by pretreatment with high doses of vitamin D and, at the dose level employed, there was no evidence of "resistance" to vitamin D. Dietary restriction depressed the gastrointestinal transport of calcium and may play a role in producing the defect in calcium transport of chronic uremia.