pH is decreased in transplanted rat pancreatic islets.
Recent studies of transplanted pancreatic islets have indicated incomplete revascularization. We investigated the pH, in relation to oxygen tension (Po(2)), in endogenous islets and islets syngeneically transplanted to the renal subcapsular site of nondiabetic and streptozotocin-diabetic recipients. Tissue pH and Po(2) were measured using microelectrodes. In the endogenous islets, tissue pH was similar to that in arterial blood. In the transplanted islets, tissue pH was 0.11-0.15 pH units lower. No differences in islet graft pH were seen between nondiabetic and diabetic animals, and none if the islet grafts were investigated 1 day or 1 mo posttransplantation. The Po(2) in the endogenous islets was approximately 35 mmHg. Transplanted islets had a markedly lower tissue Po(2) both 1 day and 1 mo after transplantation. A negative correlation between the tissue Po(2) and the hydrogen ion concentration was seen in the 1-mo-old islet transplants in diabetic animals. In conclusion, decreased Po(2) in transplanted islets is associated with a decreased tissue pH, suggesting a shift toward more anaerobic glucose metabolism after transplantation.
Carlsson
Per-Ola
PO
Department of Medical Cell Biology, Uppsala University, SE-751 23 Uppsala, Sweden. Per-Ola.Carlsson@medcellbiol.uu.se
Nordin
Astrid
A
Palm
Fredrik
F
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001835:Body Weight; D006859:Hydrogen / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007328:Insulin / Q000378:metabolism; D007515:Islets of Langerhans / Q000378:metabolism*; D016381:Islets of Langerhans Transplantation; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D010100:Oxygen / Q000378:metabolism; D010313:Partial Pressure; D019289:Pyruvic Acid / Q000378:metabolism; D051381:Rats; D011920:Rats, Inbred WF; D016042:Transplantation, Heterotopic
D001786:Blood Glucose; D007328:Insulin; D019344:Lactic Acid; D006859:Hydrogen; D019289:Pyruvic Acid; D010100:Oxygen