Leptin does not reduce body fat content but augments cold defense abilities in thermoneutrally reared rat pups.
A previous study showed that recombinant leptin markedly affects the body fat content and thermoregulatory energy expenditure of lean (+/+ and +/fa) suckling-age rats, and we wanted to find out whether leptin in doses that halved body fat of cold-reared lean pups had any effect in thermoneutrally reared lean pups. When +/+ pups were artificially reared from 4 to 16 days of age at thermoneutrality and treated as before with leptin from day 7, their total metabolic rate throughout the treatment period was only 4% higher than that of the control littermates and their final body fat content only 4% lower (both P>0.05). We conclude from comparisons of the results in +/+ pups at cold and thermoneutral conditions that leptin does not stimulate, but rather disinhibits, sympathetically mediated thermoregulatory thermogenesis.
Stehling
O
O
Max-Planck-Institut für physiologische und klinische Forschung, W.G. Kerckhoff-Institut, Parkstrasse 1, D-61231 Bad Nauheim, Germany.
Döring
H
H
Nuesslein-Hildesheim
B
B
Olbort
M
M
Schmidt
I
I
D000273:Adipose Tissue / Q000187:drug effects*; D000822:Animal Husbandry; D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism / Q000502:physiology*; D001823:Body Composition / Q000187:drug effects*; D001831:Body Temperature / Q000502:physiology; D001833:Body Temperature Regulation / Q000187:drug effects*; D003080:Cold Temperature; D020738:Leptin; D011506:Proteins / Q000494:pharmacology*; D051381:Rats; D011914:Rats, Inbred BN; D011924:Rats, Zucker; D013696:Temperature
D020738:Leptin; D011506:Proteins