Endotoxin-induced hypocalcemia results in defective calcium mobilization in rats

Hypocalcemia is common in critically ill patients with sepsis; however, its etiology remains unclear. We have previously reported that hypocalcemia occurs in approximately 20% of patients with gram-negative septicemia. Based upon this finding, we evaluated the effect of endotoxin on calcium homeostasis in laboratory animals. We report here that endotoxin produces a dose-related decrease in circulating ionized calcium levels and impairs calcium mobilization during ethylenebis (oxyethylenenitrilo)-tetraacetic acid infusion. We conclude that endotoxin or its products can cause ionized hypocalcemia during sepsis by impairing calcium mobilization.