Short‐term effects of leptin on lipid metabolism in the rat

Abstract

In this study, we have examined the short-term effects of leptin on lipid metabolism in the rat. Acute leptin administration induced hypertriglyceridaemia (31% increase in plasma triacylglycerols) which was not associated with changes in lipoprotein lipase activity in white adipose tissue. Surprisingly, leptin administration did not induce any changes in the lipogenic rate in either white adipose tissue or liver. Leptin administration caused a decreased tissue uptake of exogenous IR C-triacylglycerols. These data suggest that leptin induces important changes in lipid uptake in adipose tissue and skeletal muscle which could be responsible for the observed hypertriglyceridaemia.z 1998 Federation of European Biochemical Societies.

Effects of Short–Term Leptin Exposure on Triglyceride Deposition in Rat Liver

“…31 In vivo leptin treatment of both normal and leptin-deficient rodents (ob/ob mice) revealed conflicting results. Both single intravenous injection and short-term intravenous infusion of leptin did not affect hepatic contents of triglycerides, 29,32 glycerol, and citrate in ob/ob mice. 28 On the other hand, chronic hyperleptinemia induced by adenovirus gene transfer caused depletion of hepatic triglycerides in normal rats.…”

Leptin inhibits apolipoprotein M transcription and secretion in human hepatoma cell line, HepG2 cells

“…We have also reported that apoM concentration in plasma was positively correlated to leptin level in obese subjects [6]. In the present study, we further examined the effects of leptin on apoM synthesis in HepG2 Leptin is a cytokine-like peptide secreted by adipose tissue, known to regulate hepatic lipid and lipoprotein metabolism [12][13][14][15]. Mice with genetic defects in leptin exhibit hyperlipidemia, hyperinsulinemia, hyperglycemia and resistance to insulin [16][17][18].…”

Leptin stimulates uncoupling protein‐2 mRNA expression and Krebs cycle activity and inhibits lipid synthesis in isolated rat white adipocytes

“…In normal rats [15,32] and mice [33] the plasma leptin concentration ranges from values lower than 1 ng´mL 21 to 5 ng´mL…”

“…The signals on the autoradiograms were quantified by scanning photodensitometry using Image Quant Software version 3.3 (Molecular Dynamics, Sunnyvale, CA, USA). Hybridization of the blots with a [g- 32 P]ATP-labeled synthetic oligonucleotide specific for the 18S rRNA subunit was used to correct for differences in the amounts of RNA loaded onto the gel.…”