Avogaro A, Cryer PE, Bier DM. Epinephrine's ketogenic effect in humans is mediated principally by lipolysis.
THE AMERICAN JOURNAL OF PHYSIOLOGY 1992;
263:E250-60. [PMID:
1514604 DOI:
10.1152/ajpendo.1992.263.2.e250]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
To quantify epinephrine's effects on acetoacetate and beta-hydroxybutyrate kinetics, we infused subjects with 0.3 and 2.5 micrograms/min epinephrine, either alone or with a concomitant somatostatin infusion with insulin, glucagon, and growth hormone replaced at postabsorptive levels (islet clamp). Additional subjects received no epinephrine but sequential infusions of heparin plus 10% Intralipid at rates of 0.5 and 3.0 ml/min. Both epinephrine and Intralipid increased ketone body appearance (unaffected by islet clamp), augmented the interconversion rates between ketone bodies and, during the 2.5 micrograms/min infusion, caused a marked increase in beta-hydroxybutyrate appearance. The fraction of plasma free fatty acid (FFA) flux appearing as plasma ketones increased from 6 to 7% in the basal state to 11% at the high-epinephrine infusion. This fraction was also unaffected by the islet clamp and was not different from values obtained at similar Intralipid plus heparin-induced elevations in plasma FFA levels. We conclude that epinephrine's ketogenic effect in humans is primarily the result of its lipolytic effect, is accompanied by a significantly increased rate of ketone body interconversion, is manifest largely as an increase in plasma beta-hydroxybutyrate appearance at high plasma epinephrine values, and is not limited by portal insulin at post-absorptive levels.
Collapse