Splanchnic Hemodynamic Responses to Glucagon

Glucagon, a substance originally thought exclusively to play a part in carbohydrate metabolism, has during recent years been found to possess several other important properties. Among them are influence on tubular reabsorption of electrolytes, 1 on adrenal medullary secretion, 2 on calcium metabolism, 3 on gastric secretion, 4 and on gastrointestinal motility. 5,6 During the last decade, cardiovascular effects have been added to the increasing list of glucagon characteristics. Shoemaker et al 7 reported an increase in liver blood flow after glucagon administration. They used the sulfobromophthalein (Bromosulphthalein [BSP]) sodium technique to study the hepatic blood flow. The flow increase paralleled the blood glucose rise. Merrill et al 8 demonstrated a vasodilatory effect of glucagon on the splanchnic vascular bed in perfusion experiments. Parmley et al 9 reported an inotropic and chronotropic effect on cardiac activity following glucagon injection in man. In a recent publication, Kock et al, 10 using