Leptin selectively increases energy expenditure of food-restricted lean mice.
OBJECTIVE
To find out whether leptin can attenuate hypometabolic torpor-like states of metabolic rate (MR) in adult lean animals, as it attenuates the morning suppression of thermoregulatory thermogenesis in suckling-age rat pups.


METHODS
Leptin effects on MR and food intake were studied in mice aged 4-7 months, in which a high incidence of exaggerated circadian reductions of MR had been induced by chronic food-restriction and, for comparison, in free-feeding mice.


METHODS
Continuous recordings of MR, for a group of seven mice maintained at an ambient temperature of 24 degrees C, while they were repeatedly-with pauses of at least six days-treated for three consecutive days with either recombinant murine leptin (20, 200 or 600 pmol x g(-1) x d[-1]) or saline.


RESULTS
Leptin treatment caused dose-dependent 5-15% increases in energy expenditure by moderating the decreases in MR during the circadian minima, without affecting either the MR during the circadian maxima or food intake. Similar treatment of free-feeding mice caused dose-dependent decreases of food intake without changing MR.


CONCLUSIONS
Leptin controls thermoregulatory energy expenditure when food supplies are scarce and changes food intake, rather than energy expenditure, when food is abundant.
Döring
H
H
Max-Planck-Institut für physiologische und klinische Forschung, WG Kerckhoff-Institut, Bad Nauheim, FRG.
Schwarzer
K
K
Nuesslein-Hildesheim
B
B
Schmidt
I
I
D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002940:Circadian Rhythm / Q000187:drug effects / Q000502:physiology; D015331:Cohort Studies; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects / Q000502:physiology*; D004734:Energy Metabolism / Q000187:drug effects* / Q000502:physiology; D005260:Female; D005508:Food Deprivation / Q000502:physiology*; D007279:Injections, Subcutaneous; D020738:Leptin; D051379:Mice; D008807:Mice, Inbred BALB C; D010101:Oxygen Consumption / Q000187:drug effects; D011506:Proteins / Q000008:administration & dosage / Q000494:pharmacology* / Q000502:physiology; D011897:Random Allocation; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000494:pharmacology; D013997:Time Factors
D020738:Leptin; D011506:Proteins; D011994:Recombinant Proteins