Figure 3From: Toll like receptor (TLR)-4 as a regulator of peripheral endogenous opioid-mediated analgesia in inflammation Release of opioid peptides from monocytes in response to TLR4 but not TLR2 stimulation. (A, B) Monocytes were isolated from human buffy coats and purified for CD14. Release of β-endorphin (β-END) was quantified after incubation for 15 or 120 min with different doses of LPS or Pam3CSK4 (n = 7–9, * p < 0.05, One way RM ANOVA, Student-Newman-Keuls). (C) Monocytes were separated into CD14+CD16- and CD14+CD16+ monocytes. Expression of TLR2 (green line) and TLR4 (red line) was analyzed using flow cytometry in both populations. Isotype controls are shown (black line) (representative example, n = 3). (D) β-END content after lysis of unstimulated cells was measured by ELISA in these populations, CD14+CD16- (black) and CD14+CD16+ (black striped) monocytes (n = 8, * p < 0.05 paired t-test) (E,F) CD14+CD16- and CD14+CD16+ monocytes were stimulated for 15 min with 10 μg/ml LPS (red) compared to stimulation with solvent medium (black). β-END was analyzed in the supernatant (n = 8, * p < 0.05, paired t-test). All data are presented as MEAN ± SEM.Back to article page