Glucagon injection, effects

My interest in avian adipose tissue developed in a somewhat devious way, as a consequence of observations about the effect of glucagon on the serum lipids of hyperlipemic human subjects. We found that daily repeated glucagon injection caused a marked decrease of the various lipid fractions (cholesterol, phospholipids, total fatty acids), followed by an elevation when the administration of the hormone was discontinued. This and other observations - suggested a role of glucagon in the regulation of lipid metabolism, and I decided to look into the question. 

Figure 2 indicates the unequivocal rise in blood catecholamines obtained in normal subjects within the very first minutes after intravenous glucagon injection. This effect is very transitory. In fact, table I shows that, 5 and 15 min after the glucagon injection, there is no detectable change in the catecholamines blood level in the normal subjects as well as in the hypertensive patients. On the contrary, in the two cases of pheochromocytoma, a rise in blood adrenaline and noradrenaline has been obtained. The values reached in case I.F. are particularely high in this particular case, the catecholamines blood response is completely normalized six weeks after the removal of the tumor. 

Several peptide products used in the treatment of diabetes mellitus, in addition to insulin, are currently administered by subcutaneous injection and these drugs are candidates for development of nasal formulations. Glucagon-like peptide-1 (GLP-l)-related peptides stimulate the insulin response to glucose and diminish the release of glucagon after a meal. These effects diminish the excessive postprandial increase in glucose observed after a meal in persons with type 2 diabetes mellitus. GLP-1-related peptides must be administered by subcutaneous injection before meals in order to be effective. This requirement for injection before each meal is likely to impact the utilization of these products by persons with type 2 diabetes. Exendin-4 is a GLP-1-related peptide with a molecular mass of 4.2 kDa. The development of a GLP-1-related peptide nasal formulation containing an absorption enhancer would allow patients to scll-administer one of these drugs just before a meal without the need for a subcutaneous injection. 

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