Which of the following is activated by the binding of chemotactic agents to leukocyte membrane receptors?: (A) Leukotriene B 4, (B) Histamine, (C) Phospholipase C, (D) Tumor necrosis factor
Answer is C. Phospholipase C The binding of chemotactic agents to receptors on leukocyte cell membranes causes activation of phospholipase C. A hydrolysis reaction ensues resulting in the release of calcium from intracellular stores. The increased cytosolic calcium is impoant in the movement of the cells in chemotaxis.