The XXXX anococcygeus muscle and its response to nerve stimulation and to some drugs.

@entity1169 @entity4033 @entity2997 @entity1022 @entity72761 @entity5521 @entity5333 @entity3044 @entity750 @entity112 @entity35 @entity3897 @entity1063 @entity10105 @entity855 @entity934
1. A new smooth muscle preparation, the @entity35 anococcygeus muscle, is described. The muscle is paired, thin, consists of smooth muscle only and the muscle cells are organized in parallel bundles. It has a dense adrenergic innervation distributed throughout the muscle but apparently no cholinergic innervation. The muscles are easily isolated.2. The muscle contracts to @entity1063 , @entity934 , @entity72761 , @entity750 , but not to @entity112 . @entity3044 produces contraction at high concentrations. The effects of @entity1063 and @entity934 are blocked by @entity5521 and @entity3897 respectively. The response to @entity3044 is little affected by @entity1169 .3. The muscle contracts in response to field stimulation or stimulation of extrinsic nerves. This response is completely blocked by @entity5521 but unaffected by @entity4033 or @entity3897 .4. @entity2997 10(-6)-5 x 10(-6)M blocks the motor response to nerve stimulation and potentiates that to @entity1063 . Higher concentrations of @entity2997 raise tone. In the presence of raised tone, field stimulation produces an inhibitory response insensitive to @entity4033 but abolished by @entity1022 2 x 10(-7) g/ml. This inhibitory response to stimulation can also be shown after other drugs which raise tone.5. The inhibitory response to nerve stimulation is not mimicked by @entity934 , @entity3044 or @entity855 , nor blocked by @entity3897 , @entity5521 , @entity5333 , @entity1169 , @entity4033 or @entity10105 .
