Non-adrenergic, non-cholinergic nerves in mammalian airways: their function and the role of purines.
1. Relaxations to field stimulation of sympathetic nerves were found in the guinea-pig trachea only. 2. Relaxations to field stimulation of non-adrenergic inhibitory nerves were found in the larger airways of human, monkey, guinea-pig and rabbit, but not rat. 3. Lung strips from all the mammals failed to respond to sympathetic or non-adrenergic inhibitory nerve stimulation. 4. Inhibitory beta-adrenoceptors were demonstrated in the proximal airways of all species except rabbit. 5. Of the fine airways examined, beta-adrenoceptors only were found in guinea-pig and alpha-adrenoceptors only in rabbit while rat, monkey and human tissues contained mixed populations of both receptors. 6. Adenosine is a likely candidate for the neurotransmitter in the non-adrenergic inhibitory nerves. Inhibitory receptors for adenosine were present in guinea-pig trachea although receptors for ATP are probably lacking.
D000227:Adenine Nucleotides / Q000494:pharmacology / Q000502:physiology*; D000241:Adenosine / Q000494:pharmacology / Q000502:physiology*; D000818:Animals; D002395:Catecholamines / Q000494:pharmacology; D004558:Electric Stimulation; D006168:Guinea Pigs; D000882:Haplorhini; D006801:Humans; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D018377:Neurotransmitter Agents / Q000502:physiology; D011817:Rabbits; D051381:Rats; D012137:Respiratory System / Q000187:drug effects / Q000294:innervation*
D000227:Adenine Nucleotides; D002395:Catecholamines; D018377:Neurotransmitter Agents; D000241:Adenosine