METFORMIN POTENTIATES B-CELL RESPONSE TO HIGH GLUCOSE - AN INVITRO STUDY ON ISOLATED PERFUSED PANCREAS FROM NORMAL RATS

  • 1 May 1989
    • journal article
    • research article
    • Vol. 15  (3) , 111-117
Abstract
This study investigated the effects of metformin on pancreatic A-B-and D-cell functions using the isolated perfused rat pancreas model. The lactate output rate following metformin infusion was also monitored. Metformin was infused at the low therapeutic concentration of 1.5 .mu.g/ml and its effects were evaluated in three different glycaemic conditions: during a basal infusion of 4.44 mM glucose, during a moderate increse to 8.88 mM of glucose concentration, and finally during a higher 16.66 mM glycaemic stimulus. Basal insulin secretion and B-cell release during the lower hyperglycaemic stimulus were unaffected by metformin infusion. On the coronary, the drug significantly enhanced insulin response to 16.66 mM glucose, particularly by increasing the second phase of hormone release. Glucagon and somatostatin release during metformin infusion were similar to the secretory pattern observed in the control experiments both in the basal condition and in the presence of the two different hyperglycemic stimuli. Finally metformin did not modify the lactate output rate from perfused pancreas, irrespective of the different glycemic conditions employed. Therefore our data suggest (at least in rats, in in vitro experiments but above all in the presence of markedly elevated hyperglycaemic conditions) that metformin may influence the glucose stimulatory effect on B-cell activity.