Simultaneous Estimation of Intracellular Free Mg²⁺ and pH by Use of a New pH-Dependent Dissociation Constant of MgATP

Abstract

In the present technical note for ³¹P-NMR, we used a new pH-dependent dissociation constant of MgATP, and re-estimated changes in the intracellular free Mg²⁺ concentration and pH from the chemical shifts of β- and γ-ATP during Na⁺-removal in smooth muscle. We confirmed the role of Na⁺–Mg²⁺ exchange.