title: Peripheral leptin administration alters hormone and metabolite levels in the young pig.
abstract: The present study was conducted to determine if peripheral leptin administration can alter GH secretion or feed intake in young pigs. Six, 6 kg female pigs were fasted overnight and randomly chosen to receive porcine recombinant leptin or saline injections in a crossover design. Three leptin dosages were tested over a 10 day period, 100, 200 or 500 microg/kg body mass (L100, L200 or L500). Leptin was administered in 0.2% bovine serum albumin as a bolus injection into the carotid artery. Blood samples were obtained from the jugular vein over a 24 h period. Leptin delayed feeding in pigs treated with L200 and L500 (P<0.05), while reducing overall intake in pigs treated with L100 (P<0.05). L200 or L500 depressed blood glucose (P<0.05). Plasma insulin levels were elevated by feeding in control animals, while insulin levels were depressed in pigs treated with L200 or L500 (P<0.05). L200 elevated plasma growth hormone (P<0.05) with three peaks apparent at 5, 8, and 13 h post injection. The ability for a single injection of leptin to produce significant changes in hormone and metabolite levels suggests that this peptide has a role in regulation of peripheral metabolism.
authors.affiliation: Growth Biology Laboratory, USDA-ARS, BARC-East, Bldg. 200, Rm. 207, Beltsville, MD 20705, USA. tramsay@anri.barc.usda.gov
authors.forename: T G
authors.initials: TG
authors.lastname: Ramsay
authors.forename: J A
authors.initials: JA
authors.lastname: Bush
authors.forename: J P
authors.initials: JP
authors.lastname: McMurtry
authors.forename: M C
authors.initials: MC
authors.lastname: Thivierge
authors.forename: T A
authors.initials: TA
authors.lastname: Davis
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis*; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects; D005230:Fatty Acids, Nonesterified / Q000097:blood*; D005260:Female; D013006:Growth Hormone / Q000097:blood*; D007328:Insulin / Q000097:blood; D020738:Leptin / Q000008:administration & dosage* / Q000494:pharmacology; D013552:Swine
chemical_list: D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D020738:Leptin; D013006:Growth Hormone