Serum mRNA levels of interleukin-lα and interleukin-lβ increase upon exposure to intermittent hypoxia

Intermittent Hypoxia (IH) is the most common pattern of hypoxic exposure. The pro-inflammatory cytokine Interleukin (IL)-l is present in the tissues or systemic circulation in many inflammatory conditions. Although, some earlier studies have shown that hypoxia enhanced the production of pro-inflammatory cytokines, the effects of IH on the expression of IL-1 gene have not been investigated yet. The aim of this study was to examine whether IH affects the mRNA expression levels of two IL-1 molecules, IL-lα and IL-1β in rat serum. To obtain IH, 11 male Sprague-Dawley rats were placed in a hypobaric chamber (282 mm Hg, 30 min day^-1, 14 days). The mRNA expression levels of IL-1α and IL-1β in serum were determined using quantitative real-time RT-PCR. All of the rats exposed to IH exhibited significantly higher levels of IL-1 mRNA expression than the normoxic control rats. Exposure to IH resulted in 6.0 and 6.3 fold increases in the amount of IL-1α and IL-1β mRNA when compared to that of the control group (p<0.001, both). Researchers demonstrated that the serum levels of IL-1 a and IL-1 [3 mRNA were significantly increased in rats following 14 days of exposure to IH. The result suggests that IH has a positive effect on transcription of the IL-1α and IL-1β genes.