title: Differential effects of alpha and beta adrenergic blockade on glucose and lactate metabolism during acute stress.
abstract: In this study we examined the role of alpha and beta blockade on glucose and lactate metabolism during the acute stress of insulin-induced hypoglycemia. Three groups of conscious dogs with chronically fitted catheters in the femoral artery and in the femoral, portal, and hepatic veins were studied after an 18-hr fast. After a 1-hr basal period, hypoglycemia was induced with insulin infusion at 5 mU/kg.min for 3 hr. Group 1 received no other treatment. Groups 2 and 3 received, respectively, phentolamine (8 micrograms/kg.min) and propranolol (4 micrograms/kg.min) beginning 30 minutes before and throughout the experimental period. Despite similar hyperinsulinemia, plasma glucose dropped in Group 1 (from 115 +/- 10 to 40 +/- 3 mg/dl) and in Group 2 (from 110 +/- 4 to 60 +/- 3 mg/dl) but in Group 3 it was maintained at 45 +/- 4 mg/dl by exogenous glucose infusion at a rate of 2.2 +/- 0.4 mg/kg.min. Hepatic glucose production increased 50 +/- 13%, 127 +/- 30%, and 55 +/- 30% in Groups 1, 2, and 3, respectively, within 60 minutes and was 56 +/- 19%, 55 +/- 17%, and -0.04 +/- 12% during the last hour of the experiment. Glucose utilization did not change in Groups 1 and 2 but it increased in Group 3. Plasma lactate increased in Group 1 (from 850 +/- 190 to 1,980 +/- 450 mumol/L) and in Group 2 (985 +/- 180 to 4,785 +/- 500 mumol/L), while in Group 3 there was an early rise (to 695 +/- 120 mumol/L) within 30 minutes that gradually dropped to near basal.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee 37232.
authors.forename: H
authors.initials: H
authors.lastname: Hourani
authors.forename: D B
authors.initials: DB
authors.lastname: Lacy
authors.forename: T M
authors.initials: TM
authors.lastname: Nammour
authors.forename: N N
authors.initials: NN
authors.lastname: Abumrad
authors.forename: J A
authors.initials: JA
authors.lastname: Morris
mesh_terms: D000818:Animals; D001786:Blood Glucose; D004285:Dogs; D005260:Female; D005947:Glucose / Q000378:metabolism*; D006439:Hemodynamics / Q000187:drug effects; D007003:Hypoglycemia / Q000139:chemically induced / Q000378:metabolism*; D007328:Insulin / Q000097:blood / Q000633:toxicity; D007773:Lactates / Q000097:blood / Q000378:metabolism*; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D010646:Phentolamine / Q000633:toxicity; D011433:Propranolol / Q000633:toxicity; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects*; D011943:Receptors, Adrenergic, beta / Q000187:drug effects*
chemical_list: D001786:Blood Glucose; D007328:Insulin; D007773:Lactates; D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D011433:Propranolol; D005947:Glucose; D010646:Phentolamine