Effect of exogenous insulin and glucagon on exocrine pancreatic secretion in rats in vivo.
BACKGROUND
The physiological roles of the islet hormones insulin and glucagon in the control of exocrine pancreatic secretion is not clear. It is still unknown whether these hormones have a stimulatory or an inhibitory effect on the basal exocrine pancreatic secretion.


METHODS
Thirty anesthetized rats were stimulated with doses of insulin and glucagon administered by continuous intravenous infusion. Doses varying from physiological to supraphysiological were used. Different groups of 5 rats were given each of these doses. The volume of pancreatic juice and amylase, lipase and trypsin activity, as well as enzyme output, were measured 0, 20, 40, and 60 min after starting infusion. The insulin, glucagon, and glucose levels were determined in serum at 0, 10, 30, and 60 min.


RESULTS
In the insulin group, the secreted volume of pancreatic juice increases with the maximum dose. All insulin doses results in amylase and lipase decreased activity. When submaximum and maximum insulin doses are administered, the trypsin activity also decreases. In the glucagon group, the activity of lipase and trypsin decreases regardless the dose, whereas the amylase activity decreases with submaximum and supramaximum doses.


CONCLUSIONS
Both insulin and glucagon affect the basal exocrine pancreatic secretion in vivo when physiological doses are administered.
Ferrer
R
R
Department of Pathology and Surgery, School of Medicine, Miguel Hernandez University, Elche, Alicante, Spain. umraferi@umh.infoville.net
Medrano
J
J
Diego
M
M
Calpena
R
R
Graells
L
L
Moltó
M
M
Pérez
T
T
Pérez
F
F
Salido
G
G
D000681:Amylases / Q000378:metabolism; D000818:Animals; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D005934:Glucagon / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D007262:Infusions, Intravenous; D007328:Insulin / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D008049:Lipase / Q000378:metabolism; D008297:Male; D010179:Pancreas / Q000098:blood supply / Q000187:drug effects / Q000378:metabolism*; D010189:Pancreatic Juice / Q000187:drug effects / Q000201:enzymology; D011168:Portal System / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D014357:Trypsin / Q000378:metabolism
D001786:Blood Glucose; D007328:Insulin; D005934:Glucagon; D008049:Lipase; D000681:Amylases; D014357:Trypsin