Fig. 8.

Mg deficiency enhances CIS-induced renal cell apoptosis in vivo and increases CIS-mediated killing of LLC-PK₁ cells: reversal by Mg replacement. Mice were maintained on either 100% Mg or 10% Mg-deficient diets or were maintained on a 10% Mg diet followed by Mg supplementation, as described in methods, and then treated with saline (CTRL) or CIS (12 mg/kg). All mice were euthanized 48h post-CIS (or saline). Renal apoptosis was measured by TUNEL staining. A and B: representative photomicrographs (at ×200 magnification) in a complete representative section (A) and a selected area in the section (B). C: apoptosis was determined by counting the number of TUNEL-positive cells per HPF using random sections, and mean apoptosis scores ± SE are shown. Scale bar = 20 μm. *P < 0.05 vs. CTRL; †P < 0.05 vs. CIS; ‡‡‡P < 0.001 vs. MgD + CIS. D: LLC-PK₁ cells were maintained in either 100% Mg or 10% Mg (Mg-deficient) media or 10% Mg media followed by 200% Mg replacement (10% Mg/200% Mg). Cell viability was measured 24 h post-CIS using a neutral red assay, and data are shown as means ± SD (as %viability). ***P < 0.001 vs. 100% Mg + CIS; ‡‡‡P < 0.001 vs. 10% Mg + CIS.