Leptin binding in the arcuate nucleus is increased during fasting.
The arcuate nucleus (ARC) mediates the anorexic effects of leptin and expresses the long form (Ob-Rb) of the leptin receptor. To determine whether ARC leptin binding increases when plasma leptin levels are low during fasting, [125I]-leptin specific binding to rat brain slices was measured by quantitative autoradiography. [125I]-leptin specific binding was dense in the ARC and increased 2-fold after a 48-h fast (P<0.001). These findings suggest that leptin receptor binding in the ARC is upregulated during fasting and that fasting changes the sensitivity of the ARC to leptin.
D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D004435:Eating / Q000502:physiology; D005215:Fasting / Q000502:physiology*; D007457:Iodine Radioisotopes; D020738:Leptin; D008297:Male; D009478:Neuropeptide Y / Q000378:metabolism; D011333:Pro-Opiomelanocortin / Q000378:metabolism; D011506:Proteins / Q000378:metabolism / Q000494:pharmacology*; D011869:Radioligand Assay; D051381:Rats; D017208:Rats, Wistar; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin