studies

468A AASLD ABSTRACTS HEPATOLOGY, October, 2015
of HSC. We are now carrying out the molecular analyses of
CYGB promoter activation stimulated by phosphorylated JNK.
Disclosures:
Massimo Pinzani - Advisory Committees or Review Panels: Intercept Pharmaceutical,
Silence Therapeutic, Abbot; Consulting: UCB; Speaking and Teaching:
Gilead, BMS
Norifumi Kawada - Grant/Research Support: BMS, Chugai, Kowa; Speaking
and Teaching: MSD, Janssen
The following authors have nothing to disclose: Misako Sato, Matsubara, Tsutomu
Matsubara, Atsuko Daikoku, Krista Rombouts, Kazuo Ikeda
518
Impaired skeletal muscle mitochondrial respiration
during hyperammonemia of cirrhosis contributes to sarcopenia
Julie H. Rennison 2 , Avinash Kumar 2 , Gangarao Davuluri 2 , Allawy
Allawy 2,4 , Rafaella Nascimento e Silva 2 , Dharmvir Singh 2 , David
R. Van Wagoner 5 , Hoppel Charles 3 , Srinivasan Dasarathy 1 ;
1 Department Of Gastroenterology and Hepatology, Cleveland
Clinic, Cleveland, OH; 2 Pathobiology, Cleveland Clinic, Cleveland,
OH; 3 Pharmacology and Medicine, Case Western Reserve
University, Cleveland, OH; 4 Department Of Internal Medicne,
Cleveland Clinic, Cleveland, OH; 5 Molecular Cardiology, Cleveland
Clinic, Cleveland, OH
Hyperammonemia is a consistent abnormality in cirrhosis.
Skeletal muscle metabolic disposal of ammonia in cirrhosis
has been shown to contribute to sarcopenia or loss of skeletal
muscle mass. Ammonia disposal occurs in muscle mitochondria
and increased fragmentation and impaired ATP content occur
in the muscle during hyperammonemia of cirrhosis. We tested
the hypothesis that mitochondrial oxidation is decreased during
hyperammonemia and identified the specific sites on the electron
transport chain complexes (ETCC) that contribute to the
impaired mitochondrial respiration. We evaluated the impact
of hyperammonemia (AmAc) on mitochondrial respiration
in differentiated C2C12 murine myotubes by high-resolution
respirometry in the basal state in intact cells and in response
to specific substrates for the ETCC (pyruvate for complex I,
succinate for complex II, TMPD for complex III) and inhibitors
of each of the ETCC (rotenone for complex I, oligomycin for
ATP synthetase, FCCP for uncoupling oxidative phosphorylation,
antimycin A for Complex III). Control and AmAc treated
cells were were assessed in separate chambers simultaneously.
Hyperammonemia decreased basal respiration in intact cells
by ~35% (Control, 67.0±14.1; 24hr AmAc 42.3±7.9 pmol
O 2
s -1 10 -6 ) (p