[Skip to Content]
[Skip to Content Landing]
Article
December 1994

Lipolysis in Burned Patients Is Stimulated by the β2-Receptor for Catecholamines

Author Affiliations

From the Departments of Surgery (Drs Herndon, Nguyen, Wolfe, Maggi, Biolo, and Barrow, and Mr Muller) and Physiology and Biophysics (Drs Wolfe and Barrow), University of Texas Medical Branch, and Shriners Hospitals for Crippled Children, Burns Institute (Drs Herndon, Nguyen, Wolfe, Maggi, Biolo, and Barrow, and Mr Muller), Galveston.

Arch Surg. 1994;129(12):1301-1305. doi:10.1001/archsurg.1994.01420360091012
Abstract

Objective:  To determine if the cardiovascular effects of excessive catecholamines could be selectively blocked in severely burned patients without adversely affecting protein or fat kinetics.

Design:  Prospective cohort study.

Setting:  A large tertiary care referral center in Galveston, Tex.

Patients:  Sixteen patients with greater than 40% body surface area burns.

Interventions:  Patients were randomly selected to receive propranolol hydrochloride, a nonselective β1- and β2-blocker, or metoprolol tartrate, a selective β1-blocker.

Main Outcome Measures:  Heart rate; rate-pressure product; rate of appearance of urea, glucose, and leucine; and leucine oxidation were measured before and after selective or nonselective β-adrenergic blockade.

Results:  Propranolol and metoprolol caused a significant decrease in heart rate, from a mean (±SD) of 143 ± 15 to 115±11 and from 147±17 to 120±9 beats per minute, respectively, during the 5-day study period. Neither the rate of appearance of urea nor the rate of urea production were significantly altered by propranolol or metoprolol therapy. Only propranolol produced a significant decrease (P<.05) in the rate of appearance of glycerol, from a mean (±SD) of 5.54±0.62 to 3.07±0.7 μmol/kg per minute. The rate of appearance of leucine, used as an index of total body protein catabolism, was not significantly altered by either β-blocker.

Conclusions:  Selective β1-adrenergic blockade did not reduce lipolysis; however, a β1- and β2-adrenergic blockade significantly reduced lipolysis. Thus, the increased lipolysis, characteristic of severely burned patients, is caused by stimulation of the β2-adrenergic receptors for catecholamines.(Arch Surg. 1994;129:1301-1305)

×