Enhanced thermogenic response to epinephrine after 48-h starvation in humans.
The effects of 48-h starvation on the physiological responses to a 30-min infusion of epinephrine at 25 ng.min-1.kg body wt-1 were studied in 11 normal-weight healthy young subjects. Starvation led to considerable alterations in basal metabolism including a significant (mean 3.6%) increase in resting metabolic rate. During the infusions, plasma epinephrine concentration rose less in the starved state (+1.47 nmol/l) than in the normally fed state (+1.73 nmol/l) (SE 0.06 nmol/l; P less than 0.05). The maximum increments (mean +/- SE) in heart rate induced by epinephrine were 11.9 +/- 1.3 beats/min in the normally fed state and 20.1 +/- 2.0 beats/min in the starved state (P less than 0.001); the corresponding mean increments in blood glycerol concentration were 0.07 and 0.14 mmol/l (SE 0.01 mmol/l; P less than 0.01). The increase in the metabolic rate above base line during the final 10 min of the epinephrine infusion was 0.58 +/- 0.18 kJ/min in the normally fed state and 0.78 +/- 0.14 kJ/min in the starved state (P less than 0.01). The chronotropic, lipolytic, and thermogenic effects of infused epinephrine were therefore enhanced by prior starvation, despite the lower plasma epinephrine levels.
Mansell
P I
PI
Department of Physiology and Pharmacology, Queen's Medical Centre, Nottingham, United Kingdom.
Fellows
I W
IW
Macdonald
I A
IA
D020155:3-Hydroxybutyric Acid; D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D001794:Blood Pressure; D001831:Body Temperature / Q000187:drug effects*; D004837:Epinephrine / Q000097:blood / Q000494:pharmacology*; D005260:Female; D005990:Glycerol / Q000097:blood; D006339:Heart Rate; D006801:Humans; D006885:Hydroxybutyrates / Q000097:blood; D007328:Insulin / Q000097:blood; D007773:Lactates / Q000097:blood; D007866:Leg / Q000098:blood supply; D008297:Male; D009638:Norepinephrine / Q000097:blood; D012039:Regional Blood Flow; D012881:Skin Temperature / Q000187:drug effects; D013217:Starvation / Q000097:blood / Q000503:physiopathology*; D013997:Time Factors
D001786:Blood Glucose; D006885:Hydroxybutyrates; D007328:Insulin; D007773:Lactates; D005990:Glycerol; D020155:3-Hydroxybutyric Acid; D009638:Norepinephrine; D004837:Epinephrine