ELECTROACUPUNCTURE (EA) INDUCED ATTENUATION OF IMMUNOSUPPRESSION APPEARING AFTER EPIDURAL OR INTRATHECAL INJECTION OF MORPHINE IN PATIENTS AND RATS

In order to investigate the effect of epidural morphine and electroacu puncture (EA) on immune function of postoperative patients, peripheral blood for NK (natural killer) cell activity assay were obtained from patients before and on the 1st, 3rd, 7th day after cholecystectomy. 1 mg morphine injected into epidural space after surgery significantly s uppressed NK cell activities via prolonged inhibition and increased th e inhibitory intensity of it. EA of'' Zusanli (St.36), Sanyinjiao(Sp.6 ), Hegu(L.I.4) and Neiguan(P.6) points enhanced the NK cell activities after epidural injection of morphine. It was further observed that mi croinjection of 1 mu g/1 mu l naloxone into periaqueductal gray (PAG) partially antagonized the suppression of NK cell activity induced by i ntrathecal (ith) injection of 40 mu g/50 mu l morphine, and so does EA of'' Zusanli(St.36)(''). When EA applied after naloxone microinjected into PAG, the NK cell activity was further augmented as compared to t hat using EA or PAG microinjection of naloxone alone. The above result s suggested epidural morphine combined with EA is a better method to r elieve postoperative pain, and opiate receptor in PAG might partially mediate the suppression of NK cell activity induced by intrathecal inj ection of morphine. Yet, the mechanisms of the attenuation of EA on mo rphine induced immunosuppression needs further study.