EVIDENCE THAT ADRENERGIC NERVES ARE RESPONSIBLE FOR THE ACTIVE UPTAKE OF NORADRENALINE IN THE GUINEA-PIG ISOLATED TRACHEA

Abstract
1 6-Hydroxydopamine (50 mg/kg, i.p.) was given to guinea-pigs to destroy the adrenergic nerve terminals in the trachea. 2 The destruction was demonstrated by fluorescence histochemistry, which showed a marked loss of beaded fluorescent terminal fibres and by electrical transmural stimulation of the isolated atropinized trachea, which showed a marked reduction of dilator responses. 3 Such tracheae showed greatly reduced uptake-with-retention of (—)-[3 H]-noradrenaline in incubation experiments and the efflux curve of radioactive material showed a selective but incomplete reduction in the volume of the slowly exchanging compartment. 4 It is concluded that much, but perhaps not all, of the uptake-with-retention occurs into adrenergic nerves.