Preoperative assessment of adenylylcyclase activity as a functional markerof islet cell quality after transplantation in rats

To determine the potential value of measuring adenylylcyclase activity as a pretransplant functional marker of pancreatic islet cell quality, a produc tion rate of adenosine 3':5'-monophosphate was measured with a fluorometric assay in rat islet cells before transplantation. Islets were stored for di fferent periods of time (0 to 96 hours) and in different preservation solut ions. The adenylylcyclase activities of islets stored in University of Wisc onsin (UW) solution for 3 hours after isolation were significantly higher t han those stored in Hanks' balanced salt solution. Similarly, the adenylylc yclase activities of islets stored for more than 24 hours in UW solution de creased significantly with prolonged storage time. Preoperative adenylylcyc lase activity was compared with post-transplant islet function in a rat mod el of diabetes. Transplant success was evaluated by measuring blood glucose level and body weight. Although all transplants were ultimately successful in this study, the rate at which they achieved euglycemia varied, and this is the property that correlated with pre-transplant basal or forskolin-sti mulated adenylylcyclase activity Additional studies showed that it was feas ible to measure adenylylcyclase activity in human islet cells. We conclude that preoperative measurement of basal and stimulated adenylylcyclase activ ity may provide a useful clinical marker for assessing islet cell quality a nd differences in preservation media and may predict transplant success. Ba sed on these data, additional studies evaluating the feasibility of using a denylylcyclase activity as a research and clinical marker of islet cell via bility are warranted.