Investigation of relaxations of the rabbit anococcygeus muscle by nerve stimulation and ATP using the ATP antagonist ANAPP3.
Sneddon-P; Westfall-DP; Fedan-JS
Eur J Pharmacol 1982; 80(1):93-98
The effects of arylazido-aminopropionyl-adenosine-triphosphate (ANAPP3) on relaxation of the rabbit anococcygeus muscle induced by adenosine-triphosphate (9000833) (ATP) and inhibitory nerve stimulation were investigated. Anococcygeus muscles were excised from sacrificed male albino-rabbits and mounted in a water bath. One end of the muscle was fixed and the other end was attached to a transducer to monitor tension. Infused into the bath were histamine to raise muscle tone, guanethidine to block adrenergic nerve induced responses, and atropine to block cholinergic nerve induced responses. The muscle was electrically stimulated and the contractile activity was recorded. Inhibitory responses to various doses of ATP, adenosine (58617), or beta-gamma-methylene-ATP were obtained and compared with those of ANAPP3. Field stimulation induced relaxation of the muscle in the presence of atropine, histamine, and guanethidine. ATP and adenosine induced relaxations, but the beta-gamma-methylene-ATP was less potent. ANAPP3 did not reduce response to nerve stimulation. The authors conclude that responses to ATP could be mediated partly by hydrolysis products and do not support the proposal that ATP is the inhibitory transmitter in the muscle.
NIOSH-Author; Purines; Muscle-physiology; Nerve-fiber-excitation; Neuromotor-function; Electrophysiology; Animal-studies; Neurophysiology; Muscle-contraction; Physiological-response
European Journal of Pharmacology