title: Recent advances in pancreatic endocrine and exocrine secretion.
abstract: OBJECTIVE
  This review presents recent advancements in the mechanisms by which integrated signaling mechanisms elicit and regulate pancreatic endocrine and exocrine secretion.
  
  
  RESULTS
  Cholecystokinin (CCK) can stimulate exocrine secretion by acting directly on neurons located in the dorsal motor of the vagus or indirectly by acting on pancreatic stellate cells. The importance of small GTPases such as RhoA and Rac1 in CCK-induced pancreatic secretion is also described. Ghrelin attenuates insulin secretion through the AMP-activated protein kinase-uncoupling protein 2 pathway. An exciting new report describes that leptin can influence insulin release by osteoclastin, a hormone produced by osteoblasts. This finding adds a new layer of complexity in the regulation of insulin secretion with implications for glucose and energy homeostasis. In addition, leptin also mediates insulin secretion through the sympathetic system and via pro-opiomelanocortin neurons, which could serve as the cross-road for leptin and melanocortin signaling pathways. Recent reports on the action of numerous other regulators such as atrial natriuretic peptide, neurotensin, and orexin B are also discussed.
  
  
  CONCLUSIONS
  The pancreas is an extremely complex gland. Elucidation of the secretory and regulatory pathways that control pancreatic secretion will aid in the development of treatment for diseases such as pancreatitis, diabetes, and obesity.
authors.affiliation: Department of Medicine, Duke University, Durham VA Medical Centers, Durham, North Carolina 27710, USA.
authors.forename: Rashmi
authors.initials: R
authors.lastname: Chandra
authors.forename: Rodger A
authors.initials: RA
authors.lastname: Liddle
mesh_terms: D009320:Atrial Natriuretic Factor / Q000502:physiology; D002766:Cholecystokinin / Q000502:physiology*; D054439:Ghrelin / Q000502:physiology; D005947:Glucose / Q000502:physiology; D006801:Humans; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D047908:Intracellular Signaling Peptides and Proteins / Q000502:physiology; D020738:Leptin / Q000502:physiology; D053486:Melanocortins / Q000502:physiology; D009479:Neuropeptides / Q000502:physiology; D000068797:Orexins; D010179:Pancreas / Q000378:metabolism* / Q000502:physiology; D017346:Protein Serine-Threonine Kinases / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D054439:Ghrelin; C000596229:HCRT protein, human; D007328:Insulin; D047908:Intracellular Signaling Peptides and Proteins; D020738:Leptin; D053486:Melanocortins; D009479:Neuropeptides; D000068797:Orexins; D009320:Atrial Natriuretic Factor; D002766:Cholecystokinin; C116037:PAS domain kinases; D017346:Protein Serine-Threonine Kinases; D005947:Glucose