Methods: Approximately 5x105 saline or morphine (1.0μM, 16-24hrs 370C) treated and CFDA (10μM, 15 minutes 370C) labeled PLB985 human myelomonocytic cells were loaded into top wells of the transwell set-up. Bottom wells contained either 5%FBS+RPMI1640 or ovarian carcinoma derived conditioned media (MA148-CM). PLB985 cells were allowed to migrate through collagen coated, 3.0μM pores from top wells into bottom wells for 6hrs in a humidified 370C, 5% CO2 incubator. Migrated cells were collected and relative fluorescence determined using a fluorescent plate reader. The effect of morphine on granulocyte migration was further assessed on freshly isolated saline and morphine pretreated granulocytes isolated from human blood.
Results: When compared to saline, morphine significantly reduced the migration of PLB985 cells towards tumor cell derived conditioned media (p<0.05). Similarly, granulocytes isolated from human blood, showed on an average a 46% reduction in chemotaxis to MA148-CM following morphine treatment (p<0.033).
Conclusions: Opioids can reduce leukocyte migration in vitro. This potentially reduces leukocyte recruitment and may delay wound healing. Further examination is required to determine a possible mechanism.
Keywords: Immune response, Opioids and Wound healing