Figure 3. Norepinephrine-mediated suppression of wound macrophage phagocytosis is adrenoreceptor dependent.

Macrophages isolated from 120-hour wounds were pre-treated with either α- or β-adrenergic blockade for two hours prior to treatment with physiologic norepinephrine (NE +, 10⁻⁹ M) or pharmacologic norepinephrine (NE ++, 10⁻⁶ M) for 18 hours and assessment of phagocytosis of E.coli. Neither α- nor β-adrenergic blockade alone altered wound macrophage phagocytosis (p=NS, data not shown). α-adrenergic blockade partially prevented the suppression of wound macrophage phagocytosis by physiologic norepinephrine and completely blocked pharmacologic norepinephrine-mediated suppression (p=NS vs. Untreated Control). β-adrenergic blockade completely blocked physiologic norepinephrine-mediated suppression (p=NS) but did not prevent the suppression of wound macrophage phagocytosis by pharmacologic norepinephrine (*p<0.05). Combined α- and β-adrenergic blockade prevented both physiologic and pharmacologic norepinephrine-mediated suppression of wound macrophage phagocytosis (p=NS).