Minireview Insulin feedback action on pancreatic L-cell function

Pancreatic L L-cell function is essential for the regula- tion of glucose homeostasis and its impairment leads to diabetes mellitus. Besides glucose, the major nutrient factor, inputs from neural and humoral components and intraislet cell^cell commu- nication act together to guarantee an appropriate pancreatic L-cell function. Data obtained over the last 5 years in several laboratories have revitalized a controversial concept, namely the autocrine feedbackaction of secreted insulin on L-cell function. While, historically, insulin was suggested to exert a negative eiect on L-cells, recent data provide evidence for a positive role of insulin in transcription, translation, ion £ux, insulin se- cretion and L-cell survival. & 2002 Federation of European Biochemical Societies. Pub- lished by Elsevier Science B.V. All rights reserved.