The Second Gaddum Lecture: its origins and outcomes.

Fifty years ago, the BJP published the Second Gaddum Lecture, given by John Vane to the British Pharmacological Society. This article assesses the origins of the experiments described in the Lecture, linking them directly to Gaddum's use of bioassay, a defining feature of pharmacology. The outcomes of those experiments are also assessed, tracking those results that have survived the past five decades. Two of the major advances in cardiovascular medicine, the ACE inhibitors, as anti-hypertensives, and low-dose aspirin, to prevent thrombosis were initiated by the work in this Lecture. Physiologically significant outcomes include a new non-respiratory function of the lung, based on the metabolism of endogenous vasoactive substrates in the pulmonary circulation and the recognition of the endothelium as a highly interactive component of blood vessels. The present state of the art in pharmacology, physiology and medicine owes much to the work described in the Second Gaddum Lecture.