Leucocyte and erythrocyte magnesium levels after jejuno-ileal bypass surgery.

Leucocyte magnesium concentration was measured in 25 hypomagnesaemic patients following a jejuno-ilean bypass operation for gross obesity. The mean plasma magnesium concentration in the bypass group was 0.67 mmol/l compared with that of 0.90 mmol/l in a group of 17 healthy volunteers, but the leucocyte magnesium concentration in the two groups was not significantly different. The plasma potassium was found to be significantly lower in the bypass group but there was no significant difference in the leucocyte potassium concentration in the two groups. Simultaneous measurements of erythrocyte magnesium, sodium and potassium were made. There was no evidence of intracellular magnesium depletion on the basis of the tissues studied.