AUTHOR=Hunter James P. , Faro Letizia Lo , Rozenberg Kaithlyn , Dengu Fungai , Ogbemudia Anne , Weissenbacher Annemarie , Mulvey John F. , Knijff Laura , Gopalakrishnan Kishore , Ploeg Rutger J. 

TITLE=Assessment of Mitochondrial Function and Oxygen Consumption Measured During Ex Vivo Normothermic Machine Perfusion of Injured Pig Kidneys Helps to Monitor Organ Viability

JOURNAL=Transplant International

VOLUME=Volume 35 - 2022

YEAR=2022

URL=https://www.frontierspartnerships.org/journals/transplant-international/articles/10.3389/ti.2022.10420

DOI=10.3389/ti.2022.10420

ISSN=1432-2277

ABSTRACT=Background
Donor kidney assessment may improve organ utilisation. Normothermic Machine Perfusion (NMP) has the potential to facilitate this advance. The mechanism of action is not yet determined and we aimed to assess mitochondrial function during NMP. 
Methods
Anaesthetised pigs (n=6) had one kidney clamped for 60min.  The healthy contralateral kidney was removed and underwent NMP for 8h (healthy control (HC), n=6).  Following 60min warm ischaemia the injured kidney underwent HMP for 24h, followed by NMP for 8h (n=6). Mitochondria were extracted from fresh tissue for analysis.
Results
Injured kidneys were analysed as two separate groups (IMa, n=3 and IMb, n=3). Renal resistance was higher (0.390.29 vs. 1.650.85; p=0.01) and flow was lower (5528 vs. 74; p=0.03) during HMP in IMb than IMa. NMP blood flow was higher in IMa versus IMb (10413 vs. 5511ml/min/100g; p<0.001) After 60min NMP, O2 consumption was significantly lower in IMb versus IMa (p=<0.0001). State-3 respiration was significantly different between the groups (3719 vs. 2414 vs. 108; nmolO2/min/mg; P=0.049). Lactate levels were significantly lower in IMa versus IMb (p=0.028).
Conclusions 
Mitochondrial respiration levels during NMP may be suggestive of kidney viability. Oxygen consumption, renal blood flow and lactate can differentiate severity of kidney injury during NMP.