OPIOIDS INDUCE APOPTOSIS: EXPERIMENTAL EVIDENCE AND CONSIDERATIONS

SUMMARY Experimental and clinical evidence has shown that opioids significantly influence the immune system. Subjects who are addicted to opioids show a decrease of their immunological defences which is certainly due to poor hygiene in their life style but is also caused by other co-factors, such as a direct action of the opioids. In vitro studies have shown that opioids influence the innate as well as the specific immune function. In particular, they induce a decrease in the production of the antibodies. The apoptotic action of the opioids, which was demonstrated on the neural substrate, has also been shown in bone marrow derived cells such as macrophages, fibroblasts, and above all lymphocytes. These cells have opioid receptors on the surface. The present study evaluated the apopotic effect of mu receptor agonists (morphine and buprenorphine) and k receptor agonists (pentazocin) on the leukemic T cells. The effect was antagonized (could use a better word here ?) by naloxone to confirm a receptoral mechanism. The apoptotic effect was evaluated by detecting the hypodiploid peak (showed through iodide propitio) by means of a cytofluorimeter. The results showed that both morphine and buprenorphine induced a significant hypodiploid peak which was antagonized by naloxone. Also, pentazocin induces an analogous effect (again antagonized by naloxone) even if the peak was lower. In conclusion, one of the principal ways through which opioids influence the immunological system could be the induction of the immune cell apoptosis and this phenomena seems related to direct receptoral mechanism.