The influence of high and low doses of diltiazem on isolated alveolar type II cells during normothermic and hypothermic ischemia: cytoprotection or cytotoxicity?

The alteration of calcium homeostasis is of outstanding importance for the cytotoxic reactions that place after ischemia, for this reason calcium channel blockers have been used with the purpose to protect the lung during transplantation. This work analyses the effect of Diltiazem at two different doses (10 mg/l and 50 mg/l) on Wistar rat alveolar type II cells, incubated for 8 hours at 37 degrees C and at 4 degrees in an electrolytic solution. Total protein content and the rate of protein synthesis derived from 35S Methionine uptake were used to evaluate cells viability. The data showed that Diltiazem did not improve cellular viability after warm and cold metabolic ischemia either using 10 mg/l or 50 mg/l, while at 4 degrees C a significantly cytotoxic effect (p0.05) was observed. At this temperature toxicity was independent on the dose used.