title: Transcriptional levels of growth factors in skeletal muscle of maintenance hemodialysis patients.
abstract: This study was performed to assess the mRNA levels in skeletal muscle of maintenance hemodialysis (MHD) patients. Fifty-one sedentary MHD patients and 21 sedentary normal adults of similar age, gender distribution, and racial/ethnic mix as the patients were examined. The subjects had needle muscle biopsy to measure mRNA levels. They were assessed in right vastus lateralis muscle for insulinlike growth factor I (IGF-IEa and IGF-IEc), IGF-II, the IGF-I receptor, the IGF-II receptor, and myostatin. mRNA was measured by real-time polymerase chain reaction amplification of reverse transcribed cDNA. The results showed that in the MHD patients, as compared with the normal control patients, skeletal muscle mRNA levels for IGF-IEa, IGF-II, and the IGF-I receptor were significantly reduced, whereas mRNA for IGF-IEc, IGF-II receptor, and myostatin were not different than normal. We conclude that sedentary MHD patients show reductions in mRNA levels in the right vastus lateralis muscle for certain growth factor proteins, notably IGF-IEa, IGF-II, and the IGF-I receptor. These abnormalities may contribute to the sarcopenia and impaired endurance capacity, strength, and physical performance that occur in MHD patients.
authors.affiliation: Los Angeles Biomedical Research Institute, Division of Nephrology and Hypertension, Harbor-UCLA Medical Center, Torrance, California 90501, USA. jkopple@rei.edu
authors.forename: Joel D
authors.initials: JD
authors.lastname: Kopple
authors.forename: Huiyuan
authors.initials: H
authors.lastname: Wang
authors.forename: Mario
authors.initials: M
authors.lastname: Fournier
authors.forename: Thomas
authors.initials: T
authors.lastname: Storer
authors.forename: Su Mei
authors.initials: SM
authors.lastname: Zhang
authors.forename: Hyun Yong
authors.initials: HY
authors.lastname: Song
authors.forename: Michael
authors.initials: M
authors.lastname: Lewis
mesh_terms: D000328:Adult; D005006:Ethnicity; D005260:Female; D006133:Growth Substances / Q000235:genetics*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000235:genetics; D007335:Insulin-Like Growth Factor II / Q000235:genetics; D007676:Kidney Failure, Chronic / Q000150:complications / Q000503:physiopathology* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009124:Muscle Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000737:chemistry* / Q000503:physiopathology; D055435:Myostatin; D010807:Physical Endurance; D012333:RNA, Messenger / Q000032:analysis* / Q000235:genetics; D017526:Receptor, IGF Type 1 / Q000235:genetics; D017527:Receptor, IGF Type 2 / Q000235:genetics; D006435:Renal Dialysis; D016212:Transforming Growth Factor beta / Q000235:genetics
chemical_list: D006133:Growth Substances; C525911:MSTN protein, human; D009124:Muscle Proteins; D055435:Myostatin; D012333:RNA, Messenger; D017527:Receptor, IGF Type 2; D016212:Transforming Growth Factor beta; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D017526:Receptor, IGF Type 1