2018.04.10 Glucose control of glucagon secretion – elusive mechanisms continue to puzzle
题 目：Glucose control of glucagon secretion – elusive mechanisms continue to puzzle
报告人：Erik Gylfe, Ph.D.
Professor, Department of Medical Cell Biology, Uppsala University, Sweden
主持人: 陈良怡 教授
In contrast to the general consensus about basic aspects of glucose-stimulated insulin release, glucose control of glucagon secretion continues to puzzle scientists. Despite decades of research, fundamentally different hypotheses still emerge. This presentation will review some of the proposed models and discuss their relevance for control of glucagon secretion. Evidence will be presented that glucagon secretion during hypoglycaemia depends on a-cell-intrinsic regulation of hormone release, whereas paracrine mechanisms become important in hyperglycaemia. Although Ca2+ is generally regarded as the trigger of glucagon secretion, its role in the a-cell may be more permissive and regulation instead depend on changes in cAMP.
Dr. Erik Gylfe is a professor emeritus at the department of Medical Cell Biology. He started medical studies at Umeå University in 1968 where he got his PhD in 1974. He moved to Uppsala University in 1976 and made a postdoctoral period at University of Pennsylvania, Philadelphia in 1979. He then held various positions at the Swedish Research Council and Uppsala University where he was appointed Professor of Secretion Research at the Department of Medical Cell Biology in 1994, became Chairman in 2009 and Emeritus in 2014.
His research has focused on signal transduction of hormone secretion in particular the blood glucose-regulating hormones insulin and glucagon. Apart from authoring more than 200 scientific publications he supervised 18 theses dealing with islet hormone secretion and 6 about parathyroid hormone secretion. A common denominator in Gylfe’s expertise is various cell physiological and cell biological approaches for studying intracellular messenger kinetics and secretion at the level of single cells that are either isolated or located in their natural environment (e.g. within the pancreatic islet). He pioneered studies of Ca2+ signalling and demonstrated that Ca2+ oscillations underlie pulsatile insulin release. More recent studies involve oscillatory signalling of other messengers like cAMP and the mechanisms that determine phase relationships between pulsatile release of insulin, somatostatin and glucagon.