Abstract
Renal inorganic phosphate (Pi) transport is impaired in familial hypophosphatemic rickets (FHR). Short et al. (Science, 179, 700, 1973) have reported that the mutation was also expressed in the gut. We have examined Pi uptake in vitro by jejunal mucosa from 7 (4 female, 3 male) FHR mutants (from 5 pedigrees) and 6 controls. Peroral samples were incubated for 5 to 40 minutes in TRIS buffer, pH 7.4 with substrate concentrations from 0.003 to 3 mM. Pi uptake was concentrative and energy dependent reaching mean distribution ratios (intracellular/extracellular 32P) of 4.2 ± 0.9 in controls and 5.0 ± 0.5 in patients after incubation with 0.003 mM 32Pi for 40 minutes. Incorporation of Pi in the organic pool was rapid and equilbrated after 10 minutes at a 32Pi/total 32P ratio of 0.5, at old substrate concentrations, in both groups. Only one mediated transport system for Pi was present in control subjects, with a Michael is constant ≃0.2 mM and a maximum velocity ≃0.7 mmoles per liter per 40 minutes. Similar kinetic values were obtained in the group of FHR patients. These observations do not support the thesis that a significant defect for Pi uptake is present in the jejunal mucosa of FHR mutants.
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Glorieux, F., Travers, R., Delvin, E. et al. Intestinal phosphate transport in familial hypophosphatemia. Pediatr Res 8, 893 (1974). https://doi.org/10.1203/00006450-197411000-00008
Issue Date:
DOI: https://doi.org/10.1203/00006450-197411000-00008