Effect of Intrapancreatic Administration of Vasoactive Intestinal Peptide upon the Release of Insulin and Glucagon in Dogs

Abstract

To investigate the effect of vasoactive intestinal peptide (VIP) on the endocrine function ofthe pancreatic islet, experiments with a local circulation of the pancreas were performed in anesthetized dogs. VIP was infused into the pancreatic artery in doscs of 20, 100,200 and 400 ng for 10 min. Blood glucose level in the femoral artery did not change during and after the infusion of VIP. Since VIP is known to increase blood !low, a circuit was made in the pancreatic vein and blood !low rate of the pancreatic vein was calculatcd from the time necessary to obtain a volume of blood. Blood !low rate of the pancreatic vein did not change throughout the experiment with graded doses of VIP. Plasma insulin in the pancreatic vein increased transiently following the infusion of 20 ng VIP but a constant and significant rise of plasma insulin was observed in the experiment with 400 ng of VIP. To the contrary, plasma glucagon in the pancreatic vein increased significantly after the infusion of VIP in doses of 20 to 400 ng for 10 min. The changes in the secretion of these hormones were similar to those in the plasma levels of these hormones in the pancreatic vein. From the present experiment it is concluded that VIP even in a sm all dose, wh ich does not induce hyperglycemia or increase in blood flow, stimulates the secretion of insulin and glucagon from the pancreas.

Secretion of glucagon in liver cell carcinoma.

“…The previous studies from our laboratory indicate that the canine pancreas with in situ perfusion functions in response to various secretagogues for insulin and glucagon such as amino acids (Ohneda et al 1980), vasoactive intestinal peptide (Ohneda et al 1977) and caerulein (Ohneda et al 1978). As shown in Figs.…”

The Structure-Function Relationship of GLP-1 Related Peptides in the Endocrine Function of the Canine Pancreas.

“…In the present study 34 healthy mongrel dogs weighing 12 to 15 kg were used. After an overnight fast, the animals were anesthetized with sodium pentobarbital and an in situ local circulation preparation of the pancreas was made as reported previously (Ohneda et al 1977). Briefly, the abdomen was opened by a midline incision.…”

“…The GLP-1 related peptides used in the study, GLP-1 (1-37) amide, (7-37), amide, (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20), (6-37) amide and (8-37) amide, were synthesized by the stepwise solid phase method, as described previously ; Suzuki et al 1989 ). Porcine glucagon was donated by the Eli Lilly Co. (Indianapolis, IN, USA).…”

“…Neither GLP-1 (6-37), (1-37) nor (8-37) revealed the changes in insulin secretion. When arginine was infused, a significant glucagon release from the pancreas was observed during the infusion of GLP-1 (7-37), (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20), and (8-37). The other GLP-1 peptides, (1-37), , and (6-37) did not elicit any significant changes in glucagon release.…”

Effect of glicentin-related peptides upon the secretion of insulin and glucagon in the canine pancreas.

“…Glicentin-related pancreatic peptide (GRPP) was donated by Dr. Moody (Novo Institute, Denmark). A hexadecapeptide of the N-terminal portion of glicentin (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16) and an octapeptide of the C-terminal portion of glicentiLn (62-69) were donated by Dr. M. Fujino (Takeda Chemical Industries, Osaka). Porcine crystalline glucagon (Lot No.…”