Leptin administration to lactating rats is unable to induce changes in lipid metabolism in white adipose tissue or mammary gland.
During lactation in the rat, despite hyperphagia, there are no changes in either the plasma levels or the gene expression of leptin. Removal of the litter, however, results in an important increase in the circulating concentration of leptin. Administration of leptin to lactating rats resulted in no changes in the in vivo lipogenic rate and lipoprotein lipase (LPL) activity in either adipose tissue or mammary gland, although there was an increase in insulin levels as a consequence of leptin administration. Conversely, litter removal resulted in an important decrease of LPL activity and lipogenic rate in the mammary gland while an increase in these parameters took place in adipose tissue. It is concluded that leptin is not the signal responsible for the changes in lipid metabolism that take place both in adipose tissue and mammary gland following litter removal.
Departament de Bioquímica i Biologia Molecular, Facultat de Biologia, Universitat de Barcelona, Spain.
J
J
López-Soriano
F J
FJ
López-Soriano
N
N
Carbó
J M
JM
Argilés
D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D002784:Cholesterol / Q000032:analysis; D005260:Female; D005786:Gene Expression Regulation; D007328:Insulin / Q000032:analysis; D007774:Lactation / Q000502:physiology*; D020738:Leptin; D008071:Lipoprotein Lipase / Q000032:analysis; D008321:Mammary Glands, Animal / Q000378:metabolism*; D011506:Proteins / Q000032:analysis / Q000378:metabolism*; D011863:Radioimmunoassay / Q000662:veterinary; D051381:Rats; D017208:Rats, Wistar; D014280:Triglycerides / Q000097:blood
D007328:Insulin; D020738:Leptin; D011506:Proteins; D014280:Triglycerides; D002784:Cholesterol; D008071:Lipoprotein Lipase