Fig. 3From: Attenuation of intermittent hypoxia-induced apoptosis and fibrosis in pulmonary tissues via suppression of ER stress activationER stress activation is dependent on PERK pathway, but not IRE1 and ATF6 pathways. The protein levels of p-PERK (a), p-eIF2a (b) and ATF4 (c) were elevated in pulmonary tissue (n = 4). d The expression of active ATF6 was not altered after exposure to 4 weeks of IH. The expression of XBP-1 s (e) and p58IPK (f) mRNA also did not change (n = 4). *P < 0.05; **P < 0.01; ns P > 0.05Back to article page