Vitamin-K-Dependent Protection of the Renal Microvasculature: Histopathological Studies in Normal and Diseased Kidneys

摘要

Vitamin-K-dependent carboxylation of matrix Gla protein (MGP) protects the macrocircula-tion against calcification. We recently reported in a multiethnic population study that the estimated glomerular filtration rate, a microvascular trait, decreased and the risk of chronic kidney disease increased with higher circulating levels of inactive dephospho-uncarboxylated MGP, a marker of vitamin K deficiency. These findings highlighted the possibility that vitamin K might have a beneficial effect on the renal microcirculation. To substantiate these epide-miological findings, we undertook a pilot study, in which we stained renal tissue samples obtained by biopsy from 2 healthy kidney donors and 4 patients with nephropathy for carboxyl-ated and uncarboxylated MGP and calcium deposits.