Effect of amlodipine therapy on the monoclonal antibody 3G8-induced calcium signal in polymorphonuclear leukocytes of hemodialysis patients

Chronic renal failure is associated with impaired phagocytosis, This was at tributed to the PTH-induced elevation of basal levels of [Ca2+](i) of polym orphonuclear leukocytes (PMNLs) and to the small calcium transient induced by the ligation of the Fc gamma RIII receptors of these cells with 3G8 mono clonal antibodies, The blocking of the action of PTH on the PMNLs of patien ts with chronic renal failure by their treatment with a calcium channel blo cker normalized the basal levels of [Ca2+](i) of the PMNLs and reversed the defect in their phagocytic property, It is not known whether such therapy would also restore the calcium transient in the PMNLs in response to 3G8 mo noclonal antibody to normal. We examined this issue in 12 normal subjects a nd 18 hemodialysis patients; 9 of them were treated with the calcium channe l blocker, amlodipine, and the other 9 did not receive such therapy, The tr eatment with amlodipine normalized [Ca2+](i) of PMNLs as well as the calciu m transient in response to 3G8 monoclonal antibody and reversed the defect in their phagocytosis, It is concluded that chronic renal failure is associ ated with deranged calcium homeostasis of PMNLs which causes abnormalities in the function of Fc gamma RIII receptors and consequently results in impa ired phagocytosis. Therapy with a calcium channel blocker can reverse all t hese derangements in metabolism and function of PMNLs.