title: Plasma, cytosolic and membrane magnesium content in renal insufficiency.
abstract: Plasma magnesium, cytosolic (lymphocytic) and membrane (erythrocytic) magnesium concentrations were determined in 15 controls with normal renal function compared to 12 patients with renal insufficiency (chronic glomerulonephritis, serum creatinine 2.5 +/- 0.8 mg/dl, mean +/- SD). Plasma magnesium concentrations were determined by atomic absorption spectroscopy (AAS), cytosolic free magnesium with the fluorescent indicator Mag-Fura-2, and membrane magnesium by AAS, referred to membrane protein content which was determined according to Bradford's method. Plasma magnesium was 0.91 +/- 0.08 mmol/litre in controls versus 0.95 +/- 0.09 mmol/litre in renal-insufficient patients. Cytosolic free magnesium content was 2.38 +/- 0.75 mmol/litre in controls and 2.61 +/- 0.35 mmol/litre in the renal-insufficient group. In the renal-insufficient group membrane magnesium concentrations were found to be significantly increased as compared to the control group (2.85 +/- 0.62 vs 0.53 +/- 0.22 mmol/g membrane protein, mean +/- SD, P < 0.05). The results show that cell membranes may be of special importance in renal insufficiency in avoiding magnesium overload of the cell and in keeping free cytosolic magnesium stores stable.
authors.affiliation: Medizinische Universitäts-Poliklinik, Münster, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Kisters
authors.forename: C
authors.initials: C
authors.lastname: Spieker
authors.forename: M
authors.initials: M
authors.lastname: Tepel
authors.forename: F
authors.initials: F
authors.lastname: Wenserski
authors.forename: W
authors.initials: W
authors.lastname: Zidek
mesh_terms: D000328:Adult; D002462:Cell Membrane / Q000737:chemistry; D003593:Cytoplasm / Q000737:chemistry*; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D005456:Fluorescent Dyes / Q000737:chemistry; D016257:Fura-2 / Q000031:analogs & derivatives / Q000737:chemistry; D005921:Glomerulonephritis / Q000378:metabolism; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism; D008274:Magnesium / Q000097:blood / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D051437:Renal Insufficiency / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013054:Spectrophotometry, Atomic
chemical_list: D005456:Fluorescent Dyes; C058776:2-(2-(5-carboxy)oxazole)-5-hydroxy-6-aminobenzofuran-N,N,O-triacetic acid; D008274:Magnesium; D016257:Fura-2