Intraventricular insulin and leptin reduce food intake and body weight in C57BL/6J mice.
As the incidence of obesity continues to increase, adequate animal models acquire increased importance for the investigation of energy homeostatic mechanisms. Understanding the central mechanism of action of the adiposity hormones, insulin and leptin, has become particularly important as researchers examine ways to treat or prevent obesity. Although the intra-3rd-ventricular (i3vt) administration of insulin reduces food intake in several species, its effects on food intake and body weight have not been previously been assessed in mice. Male C57BL/6J mice were administered insulin i3vt (0.05, 0.1 or 0.4 microU) or leptin i3vt (5 microg/1 microl) as a positive control. As it occurs in other species, i3vt insulin dose-dependently reduced 24-h food intake and body weight, and increased hypothalamic proopiomelanocortin (POMC) mRNA. Hence, genetic manipulations that influence brain insulin sensitivity in mice can now more easily be integrated with the broader literature on energy homeostasis.
Brown
Lynda M
LM
Department of Psychiatry, University of Cincinnati, Cincinnati, Ohio 45237, USA. lmbrown6@uncg.edu
Clegg
Deborah J
DJ
Benoit
Stephen C
SC
Woods
Stephen C
SC
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001786:Blood Glucose / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects*; D005786:Gene Expression Regulation / Q000187:drug effects; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007031:Hypothalamus / Q000187:drug effects; D007276:Injections, Intraventricular / Q000379:methods; D007328:Insulin / Q000494:pharmacology*; D020738:Leptin / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011333:Pro-Opiomelanocortin / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013997:Time Factors
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin; D020738:Leptin; D012333:RNA, Messenger; D011333:Pro-Opiomelanocortin