Plasma and red blood cell magnesium concentrations in Zucker rats: influence of a high fibre diet.

Because of the possible influence of obesity and insulin levels on magnesium metabolism, we have examined plasma and red blood cell (RBC) Mg in Zucker rats. There were reduced plasma and RBC Mg levels in Zucker rats compared with Wistar rats, and phenotype differences in Zucker rats. In obese rats, a high fibre diet reduced body weight, hyperinsulinaemia and hyperlipaemia and returned the plasma Mg concentration toward normal. However RBC levels were significantly lower than in lean rats of the same strain. The significance of the altered Mg concentration in obese Zucker rats may have metabolic implications and needs further study.