Summary
To investigate the response of extrapancreatic glucagon to intraluminal stimuli, nutrients
were administered to normal and pancreatectomized dogs through a stomach tube in a
fully conscious state after an overnight fast. Plasma immunoreactive glucagon was
determined with antisera specific and nonspecific to glucagon and was designated as
IRG and total IRG, respectively. Oral glucose load elicited a decrease in plasma IRG
and a remarkable rise of plasma total IRG in a group of 6 pancreatectomized dogs,
as in the control dogs. When arginine was given, both plasma IRG and total IRG significantly
increased in a group of 5 pancreatectomized dogs, while only total IRG rose significantly
in the normal control dogs. Butter load did not reveal any changes in plasma IRG and
total IRG in a group of 5 pancreatectomized dogs, whereas only total IRG increased
in the normal control dogs. It is concluded that extrapancreatic glucagon responds
to intraluminal administration of nutrients, as pancreatic glucagon does. In addition,
gut glucagon-like immunoreactivity increased following glucose or arginine ingestion
in pancreatectomized dogs. Furthermore, the failure in response of plasma IRG and
total IRG to butter load in pancreatectomized animals suggests that its intraluminal
hydrolysis is important in the secretion of extrapancreatic immunoreactive glucagon.
Key-Words:
Extrapancreatic Glucagon
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Glucagon-Like Immunoreactivity (GLI)
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Glucose
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Arginine
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Fat