Histamine release in rats after administration of five neuromuscular blocking agents.

The effect of five neuromuscular blocking agents on histamine levels of various tissues was studied. Blood and tissue samples were taken from male rats previously treated intravenously with neuromuscular blocking agents. d-Tubocurarine proved to be the most potent histamine liberator. Alcuronium, gallamine and succinylcholine were only moderate histamine liberators, whereas pancuronium released practically no histamine. The results from the individual tissues suggest that the possible sources of increased blood histamine concentrations are tongue and skin with high histamine content. No release of histamine was found from the lung.