Effect of centrally administered glucagon on blood lipids in anesthetised dogs

Previously we have proposed the existence of the central glucagon sensitive receptors in dogs. The present study was undertaken to explore the role of centrally administered glucagon on lipids in view of the proposed theory that the hypothalamic lipomobilizing centres are sensitive to glucose or substances that affect glucose metabolism. Glucagon (0.01 microgram) administered through the intracerebroventricular (ICV) route in anesthetised mongrel dogs, caused hypolipidemia (P greater than 0.001), hypocholesterolemia (P greater than 0.001), decreased blood free fatty acid (P greater than 0.001) and triglycerides (P greater than 0.001) levels; but increased blood high density lipoprotein (P greater than 0.01) level at 30 min. These effects on the central administration of glucagon, were not observed in pancreatectomised animals and spinal cord transectomised animals. Therefore, we conclude that the lipolysis on the central administration of glucagon, is caused by the endogenous glucagon secreted from the pancreas through the sympathetic fibers.