1203 α ADRENERGICS STIMULATE NEONATAL GLUCOSE PRODUCTION LESS THAN ADRENERGICS

Abstract

Catecholamines are important in maintenance of neonatal glucose homeostasis. The relative contribution of α versus β adrenergics in control of neonatal glucose kinetics has not been established. Twenty-three term lambs [birth weight 4.4±0.2 kg (M±SEM) and age 3.8±0.4 days] were infused with 0.9% NaCL at 0.06 ml kg−1 min−1 plus 100 μCi/kg D[6- 3H] glucose by prime plus constant infusion. Ra (production)(mg · kg min−1) was measured during infusion of variable doses of epinephrine (Epi) (ng·kg−1 min−1,) with or without variable doses of propranolol (Prop) (ug · kg−1 min−1), a competitive β-adrenergic antagonist, to isolate α adrenergic effects. All basal kinetic data was comparable. Kinetic data isThere was a rise in pl. glucose in all groups infused with both epinephrine + propranolol and epinephrine alone compared to controls. While there was no significant rise in Ra with either dose of epinephrine + propranolol, there was a rise in Ra in response to the higher dose of epinephrine alone compared to controls. We conclude that α adrenergics are less important than β adrenergics in control of neonatal glucose production.