Glucagon and Catecholamines

Alpha-cell-specific expression of the glucagon gene is conferred to the glucagon promoter element by the interactions of DNA-binding proteins.

“…Studies of the transcriptional expression of deletionally mutated fusion genes introduced into animal cell lines and in mice have identified specific control elements within the 5'-and 3'-flanking regions, introns, and exons of genes (4,21,30 potentiality for differentiating into cell lineages expressing one or more of the three major islet hormones (31). Thus, cell lines derived from rat and hamster islet tumors are useful models for studies of the factors responsible for cellular differentiation and cell-specific expression of these hormone genes.Glucagon is a 29-amino-acid peptide that raises blood glucose levels through its actions on hepatic glycogenolysis and gluconeogenesis (18,39,40 Utilizing both homologous and heterologous promoters, we have identified cis-acting transcriptional elements of the glucagon gene and trans-acting nuclear factors capable of interacting with these elements in a sequence-specific manner to confer islet and alpha cell-specific expression. Three such cis-acting control DNA elements are found within the first 300 bp of the 5'-flanking region of the glucagon gene (Gl to G3).…”

“…Glucagon is a 29-amino-acid peptide that raises blood glucose levels through its actions on hepatic glycogenolysis and gluconeogenesis (18,39,40 Utilizing both homologous and heterologous promoters, we have identified cis-acting transcriptional elements of the glucagon gene and trans-acting nuclear factors capable of interacting with these elements in a sequence-specific manner to confer islet and alpha cell-specific expression. Three such cis-acting control DNA elements are found within the first 300 bp of the 5'-flanking region of the glucagon gene (Gl to G3).…”

“…Glucagon is a 29-amino-acid peptide that raises blood glucose levels through its actions on hepatic glycogenolysis and gluconeogenesis (18,39,40). Expression of the glucagon gene is restricted to the alpha, or A, cells of the pancreatic islets and the L cells of the intestine.…”

Effects of glucagon on in vitro liquid production by lungs from fetal guinea pigs

“…These observations raise interesting possibilities: catecholamines can release glucagon in fetuses of rats and sheep, and glucagon can also release catecholamines, so that a powerful self activating cycle may exist 3738 However, the concentration of glucagon needed to release catecholamines is usually high, as judged by work in adults 36. Therefore this positive feedback could only work if the adrenals of neonates were notably sensitive to glucagon.…”

“…22 Glucagon at high levels is already in clinical use for diagnosing pheochromocytoma36; its ability, at far lower levels, to liberate cAMP, which can not only remove lung liquid but also stimulate surfactants,45 suggests that it may be considered for possible use in problems of the newborn lung. This is a particularly attractive possibility, as glucagon is a natural constituent of the body, not a drug, and its potential side effect of raising blood glucose could be expected to be weak, and probably of little disadvantage.…”