{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T20:50:37Z","timestamp":1790196637484,"version":"4.1.0"},"reference-count":15,"publisher":"Wiley","issue":"2","license":[{"start":{"date-parts":[[2005,10,21]],"date-time":"2005-10-21T00:00:00Z","timestamp":1129852800000},"content-version":"vor","delay-in-days":4982,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["NMR in Biomedicine"],"published-print":{"date-parts":[[1992,3]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p><jats:sup>31<\/jats:sup>P NMR spectra obtained <jats:italic>in vivo<\/jats:italic> reveal the presence of a few reasonably well defined chemical species, namely, ATP, orthophosphate (P<jats:sub>i<\/jats:sub>), and, in brain, phosphocreatine. The chemical shifts of these resonances respond to changes in concentrations of ions such as H<jats:sup>+<\/jats:sup> and Mg<jats:sup>2+<\/jats:sup> in a manner that depends on both the chemical shifts intrinsic to individual complexes and the formation or binding constants for the several complexes. Values of the appropriate formation constants are well established in the literature. We have derived estimates of the chemical shifts intrinsic to the individual complexes by analyzing high resolution spectra of solutions whose composition brackets the domain of physiological relevance. This provides information sufficient to estimate intracellular concentrations of H<jats:sup>+<\/jats:sup> and Mg<jats:sup>2+<\/jats:sup> from chemical shifts seen with <jats:italic>in vivo<\/jats:italic> spectra. The primary finding is an estimate of 0.3 m<jats:sc>M<\/jats:sc> for the concentration of free magnesium in human brain. Differing values are obtained from other tissues.<\/jats:p>","DOI":"10.1002\/nbm.1940050202","type":"journal-article","created":{"date-parts":[[2007,3,4]],"date-time":"2007-03-04T09:05:33Z","timestamp":1172999133000},"page":"53-58","source":"Crossref","is-referenced-by-count":50,"title":["Assessment of magnesium concentrations by <sup>31<\/sup>P NMR <i>in vivo<\/i>"],"prefix":"10.1002","volume":"5","author":[{"given":"H. R.","family":"Halvorson","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A. M. Q.","family":"Vande Linde","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J. A.","family":"Helpern","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"K. M. A.","family":"Welch","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2005,10,21]]},"reference":[{"key":"e_1_2_1_2_2","doi-asserted-by":"publisher","DOI":"10.1016\/0002-8703(79)90108-X"},{"key":"e_1_2_1_3_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi00711a001"},{"key":"e_1_2_1_4_2","doi-asserted-by":"crossref","first-page":"176","DOI":"10.1016\/S0021-9258(18)81382-5","article-title":"Nuclear magnetic resonance spectra of adenosine di\u2010 and triphospha","volume":"237","author":"Cohn M.","year":"1962","journal-title":"J. Biol. Chem."},{"key":"e_1_2_1_5_2","doi-asserted-by":"crossref","first-page":"3987","DOI":"10.1016\/S0021-9258(19)85622-3","article-title":"31P NMR studies of intracellular free Mg2+ in intact frog skeletal musc","volume":"255","author":"Gupta R. K.","year":"1980","journal-title":"J. Biol. Chem."},{"key":"e_1_2_1_6_2","doi-asserted-by":"crossref","first-page":"14420","DOI":"10.1016\/S0021-9258(18)66886-3","article-title":"31P spectroscopy, chemical analysis and free Mg2+ of rabbit bladder and uterine smooth musc","volume":"261","author":"Kushmerick M. J.","year":"1986","journal-title":"J. Biol. Chem."},{"key":"e_1_2_1_7_2","doi-asserted-by":"publisher","DOI":"10.1016\/0039-9140(67)80105-X"},{"key":"e_1_2_1_8_2","volume-title":"Computer Methods for Mathematical Computations","author":"Forsythe G. E.","year":"1977"},{"key":"e_1_2_1_9_2","unstructured":"Press W. H. Flannery B. P. Teukolsky S. A.andVetterling W. T.Numerical RecipesCambridge New York (1986)."},{"key":"e_1_2_1_10_2","doi-asserted-by":"publisher","DOI":"10.1038\/287736a0"},{"key":"e_1_2_1_11_2","first-page":"217","volume-title":"Nuclear magnetic resonance imaging and spectroscopy in stroke, in Surgery & Cerebrovascular Disease","author":"Black S. E.","year":"1987"},{"key":"e_1_2_1_12_2","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.1910100105"},{"key":"e_1_2_1_13_2","doi-asserted-by":"publisher","DOI":"10.1161\/01.STR.21.3.463"},{"key":"e_1_2_1_14_2","doi-asserted-by":"publisher","DOI":"10.1021\/ac00147a017"},{"key":"e_1_2_1_15_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0022-2828(86)80289-9"},{"key":"e_1_2_1_16_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1526-4610.1989.hed2907416.x"}],"container-title":["NMR in Biomedicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fnbm.1940050202","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/analyticalsciencejournals.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/nbm.1940050202","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,20]],"date-time":"2025-10-20T10:04:53Z","timestamp":1760954693000},"score":1,"resource":{"primary":{"URL":"https:\/\/analyticalsciencejournals.onlinelibrary.wiley.com\/doi\/10.1002\/nbm.1940050202"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1992,3]]},"references-count":15,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1992,3]]}},"alternative-id":["10.1002\/nbm.1940050202"],"URL":"https:\/\/doi.org\/10.1002\/nbm.1940050202","archive":["Portico"],"relation":{},"ISSN":["0952-3480","1099-1492"],"issn-type":[{"value":"0952-3480","type":"print"},{"value":"1099-1492","type":"electronic"}],"subject":[],"published":{"date-parts":[[1992,3]]}}}