Genome-independent effects of 1,25-dihydroxy vitamin D-3 on membrane potential.
Cell membrane potential, Vm, was monitored in rabbit hypertrophic cartilage metatarsals, amphibian proximal tubule and muscle cells during application of 1,25-dihydroxy vitamin D-3, 25-hydroxy vitamin D-3 or cholesterol (10(-10) M). 1,25-Dihydroxy vitamin D-3 elicited quick variations of Vm (in less than 1 min) in proximal tubular cells (whether injected in the lumen or in peritubular capillaries) and in cartilage. The precursor 25-hydroxy vitamin D-3 and cholesterol produced a small shift of Vm in proximal tubule only when applied from the luminal side, but this change was significantly smaller than that observed with 1,25-dihydroxy vitamin D-3. Muscle cells were unresponsive to both metabolites and cholesterol. It is concluded that rapid effects of 1,25-dihydroxy vitamin D-3 on Vm, in target cells, are specific, most likely due to permeability changes and not related to nuclear protein synthesis; they may contribute to early modulation of cell function.
D000818:Animals; D002117:Calcitriol / Q000494:pharmacology*; D002356:Cartilage / Q000473:pathology* / Q000502:physiology; D002462:Cell Membrane / Q000502:physiology*; D006984:Hypertrophy; D007684:Kidney Tubules / Q000502:physiology; D007687:Kidney Tubules, Proximal / Q000502:physiology; D008564:Membrane Potentials / Q000187:drug effects; D009132:Muscles / Q000502:physiology; D009928:Organ Specificity; D010042:Ouabain / Q000494:pharmacology; D011817:Rabbits
D010042:Ouabain; D002117:Calcitriol