Abstract: Objective · To explore the changes of pyruvate dehydrogenase (PDH) activity and pyruvate dehydrogenase kinase 4 (PDK4) expression in the end-stage renal disease (ESRD) patients' skeletal muscles. Methods · Skeletal muscle samples were collected from non-chronic kidney disease (nonCKD) patients and ESRD patients. PDH activity was detected by ELISA assay. Real-time qPCR was performed to examine gene transcription levels of PDK1-PDK4 and PDH subunits. Western blotting analysis was used to detect protein expression levels of PDK1 and PDK4. Results · There were no demographic differences between two groups of patients. Plasma creatinine and urea nitrogen were significantly elevated in ESRD group (both P<0.05), while estimated glomerular filtration rate, hemoglobin and plasma albumin in ESRD group were significantly lower than those in non-CKD group (all P<0.05). Skeletal muscle PDH activity in ESRD group was markedly lower than that in non-CKD group (P=0.014). There were no differences in PDK1- PDK4 and PDH subunits mRNA transcription levels between ESRD and non-CKD group. PDK4 protein expression was significantly higher than that in non-CKD group (P=0.000). Conclusion · The decreased PDH activity in ESRD patients' skeletal muscle may be related to up-regulation of PDK4.

Key words: end-stage renal disease (ESRD), skeletal muscle, pyruvate dehydrogenase (PDH), pyruvate dehydrogenase kinase 4 (PDK4), mitochondria