| Abstract: | Adenosine (10?5M) reduces the contractile response of the guinea-pig isolated ileum to 5-hydroxytryptamine or barium more than the responses to acetylcholine or histamine. Adenosine also inhibits the contractile response of the guinea-pig ileum to a calcium-free medium. These results suggest that adenosine effects a blockade of the indirect responses to barium or 5-hydroxytryptamine mediated through intrinsic nerves and has a weak direct inhibitory effect on the smooth muscle cells of this tissue. |
