Figure 1.

Intermittent hypoxia enhanced IL-8 protein secretion and gene expression in monocytes. THP-1 cells were treated with normoxia or intermittent hypoxia for one, three and six cycles as described in the Methods. (a) Secreted IL-8 protein was detected in the culture medium using the enzyme-linked immunosorbent assay. (b) RNA was isolated for the analysis of IL-8 gene expression by RT/real-time PCR. Note: The data are presented as the means and the standard errors of three independent experiments, * p < 0.05 vs. normoxia; † p < 0.05 vs. one IH cycle; ‡ p < 0.05 vs. three IH cycles. Abbreviations: IH = intermittent hypoxia; IL = interleukin.