K+ 141mM: Na+ 9mM: Cl- 2.2mM: total inorganic phosphate 1.4mM: free Ca2+ 52nM: free Mg2+ 0.8mM
||Theillet FX et al., Physicochemical properties of cells and their effects on intrinsically disordered proteins (IDPs). Chem Rev. 2014 Jul 9 114(13):6661-714. doi: 10.1021/cr400695p p.6663 left column 3rd paragraphPubMed ID24901537
|| Godt RE, Maughan DW. On the composition of the cytosol of relaxed skeletal muscle of the frog. Am J Physiol. 1988 May254(5 Pt 1):C591-604 DOI: 10.1152/ajpcell.1988.254.5.C591PubMed ID3284380
||Primary source abstract: "This review summarizes a variety of estimates for the concentrations of the principal cytosolic constituents in frog skeletal muscle. From these estimates (listed in the APPENDIX), [investigators] chose representative values and used electroneutrality and osmotic considerations to ensure that all major constituents have been considered. Given total cytosolic concentrations of these constituents from the literature, [they] employed a computer program to calculate the concentrations of all the major ionic species in the cytosol."
||P.6663 left column 3rd paragraph: "For example, differences have been reported for some specialized tissues/organs such as resting frog muscle with 141 mM for K+, 9.0 mM for Na+, 2.2 mM for Cl–, and 1.4 mM for total inorganic phosphate, while the concentrations of free Ca2+ and Mg2+ were reported as 52 nM and 0.8 mM, respectively (primary source)."