The expressions of ER stress chaperones. Upregulation of mRNA and protein expression of Bip, PERK and CHOP were caused by hypoxia in the testes and were attenuated by CPU86017-RS and Nif. A, Bip mRNA; B, Bip protein; C, PERK mRNA; D, PERK protein; E, CHOP mRNA; F, CHOP protein. Mean ± SD, n = 10. *P < 0.05, **P < 0.01, vs. Normal; #P < 0.05, # #P < 0.01, vs. Hypoxia, $P < 0.05, vs. H+RSL (hypoxia + RS low dose).