title: Oxygenation of the Intraportally Transplanted Pancreatic Islet.
abstract: Intraportal islet transplantation (IT) is not widely utilized as a treatment for type 1 diabetes. Oxygenation of the intraportally transplanted islet has not been studied extensively. We present a diffusion-reaction model that predicts the presence of ananoxiccore and a largerpartly functionalcore within intraportally transplanted islets. Four variables were studied: islet diameter, islet fractional viability, external oxygen partial pressure (P) (in surrounding portal blood), and presence or absence of a thrombus on the islet surface. Results indicate that an islet with average size and fractional viability exhibits an anoxic volume fraction (AVF) of 14% and a function loss of 72% at a low externalP. Thrombus formation increased AVF to 30% and function loss to 92%, suggesting that the effect of thrombosis may be substantial. ExternalPand islet diameter accounted for the greatest overall impact on AVF and loss of function. At our institutions, large human alloislets (>200μm diameter) account for ~20% of total islet number but ~70% of total islet volume; since most of the total transplanted islet volume is accounted for by large islets, most of the intraportal islet cells are likely to be anoxic and not fully functional.
authors.affiliation: Department of Surgery, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Thomas M
authors.identifier: 0000-0002-3515-8807
authors.initials: TM
authors.lastname: Suszynski
authors.affiliation: Department of Surgery, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Efstathios S
authors.identifier: 0000-0001-5977-5060
authors.initials: ES
authors.lastname: Avgoustiniatos
authors.affiliation: Department of Surgery, University of Minnesota, Minneapolis, MN 55455, USA; Institute for Cellular Transplantation, Department of Surgery, University of Arizona, Tucson, AZ 85724, USA.
authors.forename: Klearchos K
authors.identifier: 0000-0002-4554-0911
authors.initials: KK
authors.lastname: Papas
mesh_terms: D064591:Allografts / Q000378:metabolism* / Q000473:pathology; D003922:Diabetes Mellitus, Type 1 / Q000601:surgery*; D006801:Humans; D000860:Hypoxia / Q000378:metabolism*; D007515:Islets of Langerhans / Q000378:metabolism* / Q000473:pathology; D016381:Islets of Langerhans Transplantation; D008962:Models, Theoretical; D009929:Organ Size; D010313:Partial Pressure; D011168:Portal System; D013927:Thrombosis / Q000378:metabolism*