Summary
In order to determine whether both insulin and C-peptide have an inhibitory action on insulin secretion, the isolated rat pancreas was perfused with exogenous rat insulin or synthetic rat C-peptide in the presence of high or low concentration of glucose. In the presence of 2.8 mM glucose, exogenous rat insulin (4 or 10 ng/ml) and C-peptide 1 and 2 (100 ng/ml) show no effect on the insulin levels in the outflow from the perfused pancreas. However, the insulin response to 16.7 mM glucose decreased in the presence of exogenous rat insulin or synthetic rat C-peptide, showing a biphasic pattern of glucose-induced insulin release. When rat insulin or C-peptide were added at 20 min and removed at 40 min while the isolated pancreas was exposed to a 60-min glucose infusion (16.7 mM), glucose-induced insulin secretion decreased during the infusion of rat insulin or C-peptide. The present study clearly showed that exogenous rat insulin and synthetic rat C-peptide 1 and 2 inhibited glucose-induced insulin secretion. Although the suppressive mechanisms of the exogenous insulin and the C-peptide on insulin release are not yet proved, the inhibitory process is considered to be related to cyclic AMP in the pancreatic B-cell.
Similar content being viewed by others
References
Best C. H., Haist R. E.: The effect of Insulin Administration on the Content of the Pancreas — J. Physiol. (Lond.)100, 142, 1941.
Chu P. C., Goodner C. J.: Lack of Functional Suppression of Pancreatic Beta-Cells during Chronic Insulin Replacement in the Rat — Endocrinology82, 296, 1968.
Dunbar J. C., McLaughlin W. J., Walsh M.-F. J., Foà P. P.: Insulin Secretion and Glucose Uptake by Isolated Islets of the Hamster. Effect of Insulin, Proinsulin and C-Peptide — Hormone metab. Res.8, 1, 1976.
Grodsky G. M., Fanska R., Schmid F. G.: Evaluation of the Role of Exogenous Insulin on Phasic Insulin Seretion — Diabetes22, 256, 1973.
Hellerström C., Gunnarsson R.: Bioenergetics of Islet Function: Oxygen Utilization and Oxidative Metabolism in the β-Cells — In:LUft R., Randle P. J. (Eds): On the Pathogenesis of Diabetes Mellitus. Casa Ed. ‘Il Ponte’, Milano, 1970; Acta diabet. lat. 7 (Suppl. 1), 127, 1970.
Hellman B., Idahl L.-Å: Pancreatic Islet Levels of Citrate under Conditions of Stimulated and Inhibited Insulin Release — Diabetes21, 999, 1972.
Idahl L.-Å.: Glucose-6-Phosphate Content in Mammalian Pancreatic β-Cells. Effects of Various Stimulators and Inhibitors of Insulin Release — Hormones2, 371, 1971.
Idahl L.-Å., Hurme P., Wahlquist Y., Hellman B.: Pancreatic β-Cell Function and Content of 6-Phosphogluconate — Hormone metab. Res.3, 141, 1971.
Iversen J., Miles D. W.: Evidence for a Feedback Inhibition of Insulin on Insulin Secretion in the Isolated, Perfused Canine Pancreas — Diabetes20, 1, 1971.
Lacy P. E.: Endocrine Secretory Mechanism — Amer. J. Path.79, 170, 1975.
Malaisse W. J., Malaisse-Lagae F.: Chronic Effects of Insulin and Glucagon upon Islet Function — Diabetologia5, 349, 1969.
Morgan C. R., Lazarow A.: Immunoassay of Insulin Using a Two-Antibody System — Proc. Soc. exp. Biol. (N.Y.)110, 29, 1962.
Ohgawara H., Tasaka Y., Kosaka K., Shizume K.: Effect of Exogenous Bonito Insulin on Endogenous Insulin Secretion in Dogs — Endocr. jap.21, 147, 1974.
Rappaport A. M., Ohira S., Coddling J. A., Empey G., Kalnins A., Lin B. J., Haist R. E.: Effects on Insulin Output and on Pancreatic Blood Flow of Exogenous Insulin Infusion into anin Situ Isolated Portion of the Pancreas — Endocrinology91, 168, 1972.
Sando H., Kanazawa Y., Kuzuya T.: Effect of Bonito Insulin on Endogenous Insulin Secretion — Amer. J. Physiol.218, 1357, 1970.
Sodoyez J.-C., Sodoyez-Goffaux F., Foà P. P.: Evidence for an Insulin-Induced Inhibition of Insulin Release by Isolated Islets of Langerhans — Proc. Soc. exp. Biol. (N.Y.)130, 568, 1969.
Steiner D. F., Oyer P. E.: The Biosynthesis of Insulin and Probable Precursor of Insulin by Human Islet Cell Adenoma — Proc. nat. Acad. Sci. (Wash.)57, 473, 1967.
Toyota T., Abe K., Kudo M., Kimura K., Goto Y.: Inhibitory Effects of Synthetic Rat C-Peptide 1 on Insulin Secretion in the Isolated Perfused Rat Pancreas — Tohoku J. exp. Med.117, 79, 1975.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Toyota, T., Abe, K. & Kudo, M. Inhibitory action of rat insulin and synthetic rat C-peptide on insulin secretion in the perfused rat pancreas. Acta diabet. lat 14, 250–256 (1977). https://doi.org/10.1007/BF02580973
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02580973