Pharmacological characterisation of cardiovascular histamine receptors in man in vivo.

Data from pharmacological studies carried out in healthy subjects using systemic histamine or impromidine and their antagonists are reviewed. Exogenous histamine by rapid injection appears to stimulate only H1-receptors. Chlorpheniramine alone antagonised the responses to histamine. The effects of cardiovascular H2-receptor stimulation are demonstrated best by a sustained and large dose of histamine given by infusion. If it be considered desirable to antagonise all the cardiovascular responses to endogenous histamine, the available pharmacological data in man suggest this would be achieved best by a combination of an H1-and H2-receptor antagonist.