Interaction of glucagon and epinephrine in the control of hepatic glucose production in the conscious dog.
Epinephrine increases net hepatic glucose output (NHGO) mainly via increased gluconeogenesis, whereas glucagon increases NHGO mainly via increased glycogenolysis. The aim of the present study was to determine how the two hormones interact in controlling glucose production. In 18-h-fasted conscious dogs, a pancreatic clamp initially fixed insulin and glucagon at basal levels, following which one of four protocols was instituted. In G + E, glucagon (1.5 ng x kg(-1) x min(-1); portally) and epinephrine (50 ng x kg(-1) x min(-1); peripherally) were increased; in G, glucagon was increased alone; in E, epinephrine was increased alone; and in C, neither was increased. In G, E, and C, glucose was infused to match the hyperglycemia seen in G + E ( approximately 250 mg/dl). The areas under the curve for the increase in NHGO, after the change in C was subtracted, were as follows: G = 661 +/- 185, E = 424 +/- 158, G + E = 1178 +/- 57 mg/kg. Therefore, the overall effects of the two hormones on NHGO were additive. Additionally, glucagon exerted its full glycogenolytic effect, whereas epinephrine exerted its full gluconeogenic effect, such that both processes increased significantly during concurrent hormone administration.
Gustavson
Stephanie M
SM
Department of Molecular Physiology and Biophysics,Vanderbilt University, Nashville, Tennessee 37232, USA. stephanie.m.gustavson@vanderbilt.edu
Chu
Chang An
CA
Nishizawa
Makoto
M
Farmer
Ben
B
Neal
Doss
D
Yang
Ying
Y
Donahue
E Patrick
EP
Flakoll
Paul
P
Cherrington
Alan D
AD
D000409:Alanine / Q000097:blood / Q000493:pharmacokinetics; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure; D003243:Consciousness; D004285:Dogs; D004837:Epinephrine / Q000097:blood*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D005934:Glucagon / Q000378:metabolism*; D005943:Gluconeogenesis / Q000502:physiology; D005947:Glucose / Q000096:biosynthesis*; D005990:Glycerol / Q000097:blood; D006003:Glycogen / Q000378:metabolism; D006339:Heart Rate; D007659:Ketones / Q000097:blood; D019344:Lactic Acid / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D008297:Male
D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D007659:Ketones; D019344:Lactic Acid; D006003:Glycogen; D005934:Glucagon; D005947:Glucose; D000409:Alanine; D005990:Glycerol; D004837:Epinephrine