Potentiation of cutaneous reactivity and blood leucocyte histamine release by deuterium oxide in human beings.

Deuterium oxide (D2O) is known to potentiate non-cytotoxic histamine release in vitro. It has been shown (5) that D2O could also potentiate in vivo immediate-type hypersensitivity in dogs and monkeys. Present studies demonstrate potentiation in vivo by D2O of the cutaneous reactivity in 48/80, PHA and Dermatophagoides cutaneous reactions in human beings. PHA histamine release from human leucocytes is also potentiated by D2O in vitro.