Phosphodiesterases (PDEs) are enzymes that regulate the function of immune cells by hydrolyzing cyclic guanosine monophosphate/cGMP and cyclic adenosine monophosphate/cAMP. PDEs are divided into subfamilies (PDE3, PDE4, PDE5 and PDE7) which are mainly found in the respiratory tract[3]. IBMX is a broad-spectrum PDE inhibitor and its IC50 values for PDE3, 4 and 5 were 6.5 ± 1.2, 26.3 ± 3.9 and 31.7 ± 5.3 μM, respectively[4]. Human proximal tubular epithelial HK-2 cells were treated with different concentrations of IBMX for 24 h to elucidate the effect of IBMX on HIF-1 mRNA expression, IBMX reduced the mRNA levels in a dose dependant manner starting from 400 M concentration. HK-2 cells treated with or without IBMX were exposed to hypoxia for different durations, and cell viability was maintained in IBMX treated group at 24 h and 48 h, and the protective effect became significant at 48 h[5].
搜索
