Matyaszczyk M, Karczmarewicz E, Czarnowska E, Reynolds R D, Lorenc R S
Department of Biochemistry and Experimental Medicine, Child's Health Centre, Warsaw-Miedzylesie, Poland.
J Nutr. 1993 Feb;123(2):204-15. doi: 10.1093/jn/123.2.204.
Isolated enterocytes were used as differential transporting cells to examine calcium homeostasis in control and vitamin B-6-deficient rats. Kinetic analysis of calcium fluxes, as well as biochemical determinations, indicated that enterocytes from control animals had high concentrations of cytosol ionized calcium (318.5 +/- 22.4 nmol/L) and a large pool of exchangeable calcium (2.72 nmol/mg protein, or 86% of total cell calcium). Vitamin B-6 deficiency resulted in a 44% reduction in total cellular calcium (1.71 +/- 0.24 vs. 3.07 +/- 0.29 nmol/mg protein), a 69% reduction in total exchangeable calcium (0.85 vs. 2.72 nmol/mg protein) and a 56% reduction in cytosol ionized calcium concentration (141.4 +/- 13.5 vs. 318.5 +/- 22.4 nmol/L). Calcium fluxes between all cellular compartments were markedly diminished as a result of vitamin B-6 deficiency. However, vitamin B-6 deficiency did not affect the basic morphological or functional features of the enterocytes, such as cell viability, cell volume, membrane permeability and protein content. Moreover, intestinal calcium transport in vivo was not affected during vitamin B-6 deficiency, perhaps due to the greater paracellular ion movement compensating for the lower transcellular transport.
分离的肠上皮细胞被用作差异转运细胞，以研究对照大鼠和维生素B-6缺乏大鼠的钙稳态。钙通量的动力学分析以及生化测定表明，对照动物的肠上皮细胞具有高浓度的胞浆游离钙（318.5±22.4 nmol/L）和大量可交换钙（2.72 nmol/mg蛋白质，占细胞总钙的86%）。维生素B-6缺乏导致细胞总钙减少44%（1.71±0.24对3.07±0.29 nmol/mg蛋白质），总可交换钙减少69%（0.85对2.72 nmol/mg蛋白质），胞浆游离钙浓度减少56%（141.4±13.5对318.5±22.4 nmol/L）。维生素B-6缺乏导致所有细胞区室之间的钙通量显著减少。然而，维生素B-6缺乏并不影响肠上皮细胞的基本形态或功能特征，如细胞活力、细胞体积、膜通透性和蛋白质含量。此外，维生素B-6缺乏期间体内肠道钙转运未受影响，这可能是由于更大的细胞旁离子移动补偿了较低的跨细胞转运。
