Experiments conducted at the University of Minnesota School of Medicine indicate insulin release may follow a two-phase pattern in which the arrival of blood sugar at the liver apparently plays a crucial role.
Frederick C. Goetz, MD, associate professor of medicine, told the fifth congress of the International Diabetes Federation at Toronto, that the first, prompt phase results in some manner from the rise in glucose concentration in the portal vein.
Only later does the direct stimulation of beta cells of the pancreas as a result of hyperglycemia, the commonly accepted mode of insulin stimulation, play a part, Goetz said.
"It is usually assumed that the major and probably sole site at which glucose acts is directly at the beta cells themselves," Goetz said. "In other words, an increase in the concentration of glucose in arterial blood reaching the pancreas is the crucial change, which in some manner leads to