RESUMO
<p><b>OBJECTIVE</b>To study possible mechanisms of Shangjuxu (ST37) and the large intestine.</p><p><b>METHODS</b>Totally 40 SD rats were selected. The distension of end colon was used as injured afferent stimulus. Activities of locus coeruleus (LC) neurons were recorded by extracellular microelectrode technique. Shangjuxu (ST37) and Hegu (L14) were needled to observe general features of discharge reactions, distention of colon induced discharge reactions of LC, and its effects on distention of colon induced discharge reactions of LC.</p><p><b>RESULTS</b>Distention of colon could induce incrased discharge of LC neurons by 127.33% ± 45.48%. But needling at Shangjuxu (ST37) and Hegu (L14) could inhibit this injured response by 38.24% ± 7.69% and 21.29% ± 13.16% respectively (all P < 0.01).</p><p><b>CONCLUSIONS</b>Needling at Shangjuxu (ST37) and afferent signals of colon distension converged and interacted with each other. Needling at Shangjuxu (ST37) could significantly inhibit colon distension induced discharge of LC neurons, which might be one of mechanisms for Shangjuxu (ST37) and the large intestine relationship.</p>