4 the results show that , in the rat annococcygeus muscle , ( 1 ) field or extrinsic nerve stimulation released only one excitatory transmitter , namely na , although receptors for both na and atp were present on the muscle , ( 2 ) alpha , beta-meatp was selective for purinoceptors and ( 3 ) there was no evidence for excitatory co-transmission in this tissue .
C0597357
na
C0034836
purinoceptors