Figure 3.

(R)- and racemic albuterol significantly suppress IL-1β + IFN-γ– mediated upregulation of GM-CSF message and protein release. (a) NHBE cells were stimulated with 10 ng/ml each of IL-1β and IFN-γ for 12 h in the presence of either control medium, 10⁻⁶ M (R)-albuterol, 10⁻⁶ M (S)-albuterol, or 10⁻⁶ M racemic (R + S) albuterol. GM-CSF message was normalized to β-actin message. Both (R)- and racemic albuterol significantly suppressed GM-CSF upregulation by the cytokines, whereas (S)-albuterol had no significant effect. Data are presented as mean ± SEM (n = 3–7). ^* Significantly greater than constitutive GM-CSF mRNA expression (P < 0.05); ^† significantly lower than cytokine-induced GM-CSF mRNA expression (P < 0.01); ^‡ significantly lower than cytokine-induced GM-CSF mRNA expression with exposure to (S)-albuterol (P < 0.01). (b) NHBE cells were stimulated with 10 ng/ml each of IL-1β and IFN-γ over a range of times in the presence of control medium, 10⁻⁵ M (R)-albuterol, or 10⁻⁵ M racemic albuterol. GM-CSF protein in culture media was measured by ELISA and normalized to total protein of cell lysates. Both (R)- and racemic albuterol significantly attenuated the increase in GM-CSF protein release elicited by IL-1β + IFN-γ after 12 h. Data are presented as mean ± SEM (n = 4–6). ^* Significantly greater than constitutive GM-CSF protein release (P < 0.01; ^** = P < 0.001). ^† Significantly lower than cytokine-induced GM-CSF protein release (P < 0.01, ^†† = P < 0.001). White bars, media only; light gray bars, IL-1β + IFN-γ; dark gray bars, + (R)-albuterol; black bars, + racemic albuterol.