Cholinergic-Adrenergic Presynaptic Interactions on the Heart in the Millisecond Range as Studied With the Pulse-to-Pulse Method

A method has been devised to study the interactions of cholinergic and adrenergic nerves in the rabbit atria, a tissue known to be densely innervated by both vagus and sympathetic nerve fibres. The atria were isolated and perfused via the ascending branches of the coronary arteries. The acetylcholine (ACh) stores were labelled with [14C]-choline and the noradrenaline (NA) stores with [3H]-NA. The radioactive compounds were separated on columns and determined by scintillation spectrometry.