title: Impact of hypothermic preservation on tissue yield and viability in pig pancreata.
abstract: BACKGROUND
  Chronic shortage of quality human cadaveric pancreata limits islet transplantation. Porcine islet xenotransplantation is being explored to increase the donor pool. For clinical-ready islets, centralized animal husbandry, Current Good Manufacturing Practice-regulated processing facilities, and organ transportation support are required. Amount of cold ischemia time (CIT) before isolation significantly affects transplantation. The goal of this study was to determine the maximum safe CIT of whole pancreata before islet isolation.
  
  
  METHODS
  Pancreata were rapidly removed from Yorkshire pigs (age, 14-22 days) and stored in modified University of Wisconsin solution or in EuroCollins solution at 4(°)C. Pancreata were processed with <1 hour CIT (control) or stored for 4 or 12 hours before isolation. Islet yield and percent purity and viability were determined after 7 days of in vitro tissue culture and maturation. Samples from nonprocessed pancreata were collected and snap-frozen in liquid nitrogen at 0, 3, 6, 9, 12, 15, and 24 hours of preservation, then analyzed for adenosine diphosphate/adenosine triphosphate ratio as a measure of tissue energetics.
  
  
  RESULTS
  Up to 12 hours in cold storage had no significant impact on overall islet yield after 7 days of in vitro culture compared with controls; islet yield at the end of the maturation process was 28,700 ± 500 islet equivalents per pancreas (mean ± SEM control yield, 30,300 ± 900 islet equivalents per pancreas); islet purity was 75 ± 5% compared with 74 ± 5% in controls. Islet viability was significantly reduced at 12 hours compared with controls (80 ± 6% vs 96 ± 5%; P < .05). The tissue adenosine diphosphate/adenosine triphosphate ratio was maintained within the first 6 hours (1.6 ± 0.1 to 1.8 ± 0.2; P = NS) but was markedly increased during the 24-hour study (3.3 ± 0.1 at 24 hours), indicating a progressive loss of adenosine triphosphate tissue stores.
  
  
  CONCLUSIONS
  Young pig pancreata can be hypothermically stored for up to 12 hours without affecting islet yield and purity; however, islet viability is reduced. These data highlight the need for uniform shipping parameters to standardize islet quality, ideally with CIT <6 hours.
authors.affiliation: Department of Surgery, University of California, Irvine, Orange, California.
authors.forename: M
authors.initials: M
authors.lastname: Alexander
authors.affiliation: Department of Surgery, University of California, Irvine, Orange, California.
authors.forename: R
authors.initials: R
authors.lastname: Krishnan
authors.affiliation: Department of Surgery, University of California, Irvine, Orange, California.
authors.forename: B
authors.initials: B
authors.lastname: Buder
authors.affiliation: Department of Surgery, University of California, Irvine, Orange, California.
authors.forename: M
authors.initials: M
authors.lastname: Lamb
authors.affiliation: Department of Surgery, University of California, Irvine, Orange, California.
authors.forename: K
authors.initials: K
authors.lastname: Laugenour
authors.affiliation: Department of Surgery, University of California, Irvine, Orange, California.
authors.forename: D
authors.initials: D
authors.lastname: Chapman
authors.affiliation: Department of Surgery, University of California, Irvine, Orange, California.
authors.forename: C E
authors.initials: CE
authors.lastname: Foster
authors.affiliation: Department of Surgery, University of California, Irvine, Orange, California; Department of Biomedical Engineering, University of California, Irvine, Orange, California. Electronic address: jlakey@uci.edu.
authors.forename: J R T
authors.initials: JR
authors.lastname: Lakey
mesh_terms: D000241:Adenosine; D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000493:Allopurinol; D000818:Animals; D050377:Cold Ischemia; D005978:Glutathione; D006982:Hypertonic Solutions; D007328:Insulin; D007515:Islets of Langerhans / Q000502:physiology*; D019188:Organ Preservation Solutions; D010179:Pancreas / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D011887:Raffinose; D013552:Swine; D013997:Time Factors; D046509:Tissue Culture Techniques; D014022:Tissue Survival / Q000502:physiology*
chemical_list: C037096:Euro-Collins' solution; D006982:Hypertonic Solutions; D007328:Insulin; D019188:Organ Preservation Solutions; C055206:University of Wisconsin-lactobionate solution; D000244:Adenosine Diphosphate; D000493:Allopurinol; D000255:Adenosine Triphosphate; D005978:Glutathione; D000241:Adenosine; D011887:Raffinose