Hepatic glucagon metabolism. Correlation of hormone processing by isolated canine hepatocytes with glucagon metabolism in man and in the dog.
AUTOR(ES)
Hagopian, W A
RESUMO
We have found that canine and rat hepatocytes convert (125I)iodoTyr10-glucagon to a peptide metabolite lacking the NH2-terminal three residues of the hormone. The peptide is released into the cell incubation medium and its formation is unaffected by a variety of lysosomotropic or other agents. Use of specific radioimmunoassays and gel filtration demonstrated in both normal subjects and in chronic renal failure patients a plasma peptide having the properties of the hormone fragment identified by cell studies. Studies of the dog revealed a positive gradient of the fragment across the liver and no differential gradient of the fragment and glucagon across the kidney. We conclude that the glucagon fragment arises from the cell-mediated processing of the hormone on a superficial aspect of the hepatocyte, the glucagon fragment identified during experiments in vitro represents the cognate of a peptide formed during the hepatic metabolism of glucagon in vivo, and measurement of the fragment by COOH-terminal radioimmunoassays could lead to an understimulation of hepatic glucagon extraction.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=424087Documentos Relacionados
- Hepatic and renal metabolism of somatostatin-like immunoreactivity. Simultaneous assessment in the dog.
- Effect of glucose, independent of changes in insulin and glucagon secretion, on alanine metabolism in the conscious dog.
- Metabolism of Parathyroid Hormone by Isolated Rat Kupffer Cells and Hepatocytes
- Thyroid hormone metabolism in primary cultured rat hepatocytes. Effects of glucose, glucagon, and insulin.
- Metabolism in immunoreactive parathyroid hormone in the dog. The role of the kidney and the effects of chronic renal disease.