title: Two-layer challenge test as an assessment to predict islet graft function.
abstract: OBJECTIVE
  To investigate graft viability assessment before transplantation using 31P-Nuclear Magnetic Resonance (NMR) spectroscopy combining a two-layer old storage method (TLM).
  
  
  METHODS
  Rat pancreases were divided into three groups and respectively subjected to 0 (group 1), and 30 minutes (group 2) of warm ischemia (WI) before procurement. Pancreases were digested and pancreatic digest tissues were preserved for 3 h using TLM. 31P-NMR spectroscopy was used to measure ATP levels of digest tissue. After TLM, the ratio of beta-adenosine triphosphate to phosphate monoester (betaATP/PME) obtained by 31P-NMR spectroscopy was evaluated. Isolated islets were assessed for yield and in vivo function separately using nude mice.
  
  
  RESULTS
  The betaATP/PME ratios were 0.11 +/- 0.04, and 0.03 +/- 0.01 in groups 1 and 2, respectively (P < 0.05). Islet yields (IEQ/pancreas) were significantly less in group 3 (P < 0.05) and the cure rate after transplantation of 200 islets to athymic nude mice were 100% (7/7), and 0% (0/7) in groups 1 and 2, respectively. We regard groups 1 as viable group and group 2 as non-viable group. The viable groups and the non-viable group were clearly distinguished by betaATP/PME ratios.
  
  
  CONCLUSIONS
  31P-NMR spectroscopy combining TLM provided an objective and rapid means to assess severity of islet graft damage prior to transplantation in the rat model.
authors.forename: Tadahiro
authors.initials: T
authors.lastname: Goto
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Fujino
authors.forename: Masaru
authors.initials: M
authors.lastname: Kanashiro
authors.forename: Yasuki
authors.initials: Y
authors.lastname: Tanioka
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Sakai
authors.forename: Takuro
authors.initials: T
authors.lastname: Yoshikawa
authors.forename: Ippei
authors.initials: I
authors.lastname: Matsumoto
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Yonson
authors.initials: Y
authors.lastname: Ku
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Kuroda
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism / Q000628:therapy; D006085:Graft Survival / Q000502:physiology*; D007515:Islets of Langerhans / Q000502:physiology*; D016381:Islets of Langerhans Transplantation / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D010179:Pancreas / Q000502:physiology; D010759:Phosphorus Isotopes; D011237:Predictive Value of Tests; D051381:Rats; D011917:Rats, Inbred Lew; D014021:Tissue Preservation / Q000379:methods
chemical_list: D010759:Phosphorus Isotopes; D000255:Adenosine Triphosphate