Effects of adrenergic blockade on glucose kinetics in septic and burned guinea pigs

We have used the primed-constant infusion of [6-3H]glucose to study the effects of phentolamine, an alpha-adrenergic blocker, and propranolol, a beta-adrenergic blocker, on glucose production and clearance in gastrostomy-fed control, septic (repeated sub-Q Escherichia coli injections), and burned (25-30% BSA) guinea pigs. Hypermetabolism and elevated glucoregulatory hormones were evident in both traumatized models, whereas their glucose kinetic response was different. Basal glucose production and clearance were elevated in the burned group and were depressed in the septic group when compared to control values. Propranolol caused a further increase in glucose production and clearance in the burned group, whereas it depressed glucose production and clearance to an even greater extent in the septic group. Phentolamine also produced an increase in glucose production and clearance in the burned group. In the septic group, phentolamine had no significant effect on glucose production, but clearance was significantly elevated. Thus, although alpha- or beta-adrenergic blockade normalized metabolic rate in both groups with respect to control animals, glucose kinetics remained different despite similar changes in counterregulatory hormones.