title: Reciprocal changes in leptin and NPY during nutritional acceleration of puberty in heifers.
abstract: Feeding a high-concentrate diet to heifers during the juvenile period, resulting in increased body weight (BW) gain and adiposity, leads to early-onset puberty. In this study, we tested the hypothesis that the increase in GnRH/LH release during nutritional acceleration of puberty is accompanied by reciprocal changes in circulating leptin and central release of neuropeptide Y (NPY). The heifers were weaned at 3.5 months of age and fed to gain either 0.5 (Low-gain; LG) or 1.0 kg/day (High-gain; HG) for 30 weeks. A subgroup of heifers was fitted surgically with third ventricle guide cannulas and was subjected to intensive cerebrospinal fluid (CSF) and blood sampling at 8 and 9 months of age. Mean BW was greater in HG than in LG heifers at week 6 of the experiment and remained greater thereafter. Starting at 9 months of age, the percentage of pubertal HG heifers was greater than that of LG heifers, although a replicate effect was observed. During the 6-h period in which CSF and blood were collected simultaneously, all LH pulses coincided with or shortly followed a GnRH pulse. At 8 months of age, the frequency of LH pulses was greater in the HG than in the LG group. Beginning at 6 months of age, concentrations of leptin were greater in HG than in LG heifers. At 9 months of age, concentrations of NPY in the CSF were lesser in HG heifers. These observations indicate that increased BW gain during juvenile development accelerates puberty in heifers, coincident with reciprocal changes in circulating concentrations of leptin and hypothalamic NPY release.
authors.affiliation: Animal Reproduction LaboratoryTexas A&M AgriLife Research Station, 3507 Highway 59E, Beeville, Texas 78102, USADepartment of Animal ScienceKleberg Center, Texas A&M University, College Station, Texas 77843, USADivision of Animal SciencesAnimal Science Research Center, University of Missouri, Columbia, Missouri 65211, USA Animal Reproduction LaboratoryTexas A&M AgriLife Research Station, 3507 Highway 59E, Beeville, Texas 78102, USADepartment of Animal ScienceKleberg Center, Texas A&M University, College Station, Texas 77843, USADivision of Animal SciencesAnimal Science Research Center, University of Missouri, Columbia, Missouri 65211, USA.
authors.forename: Rodolfo C
authors.initials: RC
authors.lastname: Cardoso
authors.affiliation: Animal Reproduction LaboratoryTexas A&M AgriLife Research Station, 3507 Highway 59E, Beeville, Texas 78102, USADepartment of Animal ScienceKleberg Center, Texas A&M University, College Station, Texas 77843, USADivision of Animal SciencesAnimal Science Research Center, University of Missouri, Columbia, Missouri 65211, USA.
authors.forename: Bruna R C
authors.initials: BR
authors.lastname: Alves
authors.affiliation: Animal Reproduction LaboratoryTexas A&M AgriLife Research Station, 3507 Highway 59E, Beeville, Texas 78102, USADepartment of Animal ScienceKleberg Center, Texas A&M University, College Station, Texas 77843, USADivision of Animal SciencesAnimal Science Research Center, University of Missouri, Columbia, Missouri 65211, USA Animal Reproduction LaboratoryTexas A&M AgriLife Research Station, 3507 Highway 59E, Beeville, Texas 78102, USADepartment of Animal ScienceKleberg Center, Texas A&M University, College Station, Texas 77843, USADivision of Animal SciencesAnimal Science Research Center, University of Missouri, Columbia, Missouri 65211, USA.
authors.forename: Ligia D
authors.initials: LD
authors.lastname: Prezotto
authors.affiliation: Animal Reproduction LaboratoryTexas A&M AgriLife Research Station, 3507 Highway 59E, Beeville, Texas 78102, USADepartment of Animal ScienceKleberg Center, Texas A&M University, College Station, Texas 77843, USADivision of Animal SciencesAnimal Science Research Center, University of Missouri, Columbia, Missouri 65211, USA Animal Reproduction LaboratoryTexas A&M AgriLife Research Station, 3507 Highway 59E, Beeville, Texas 78102, USADepartment of Animal ScienceKleberg Center, Texas A&M University, College Station, Texas 77843, USADivision of Animal SciencesAnimal Science Research Center, University of Missouri, Columbia, Missouri 65211, USA.
authors.forename: Jennifer F
authors.initials: JF
authors.lastname: Thorson
authors.affiliation: Animal Reproduction LaboratoryTexas A&M AgriLife Research Station, 3507 Highway 59E, Beeville, Texas 78102, USADepartment of Animal ScienceKleberg Center, Texas A&M University, College Station, Texas 77843, USADivision of Animal SciencesAnimal Science Research Center, University of Missouri, Columbia, Missouri 65211, USA.
authors.forename: Luis O
authors.initials: LO
authors.lastname: Tedeschi
authors.affiliation: Animal Reproduction LaboratoryTexas A&M AgriLife Research Station, 3507 Highway 59E, Beeville, Texas 78102, USADepartment of Animal ScienceKleberg Center, Texas A&M University, College Station, Texas 77843, USADivision of Animal SciencesAnimal Science Research Center, University of Missouri, Columbia, Missouri 65211, USA.
authors.forename: Duane H
authors.initials: DH
authors.lastname: Keisler
authors.affiliation: Animal Reproduction LaboratoryTexas A&M AgriLife Research Station, 3507 Highway 59E, Beeville, Texas 78102, USADepartment of Animal ScienceKleberg Center, Texas A&M University, College Station, Texas 77843, USADivision of Animal SciencesAnimal Science Research Center, University of Missouri, Columbia, Missouri 65211, USA.
authors.forename: Marcel
authors.initials: M
authors.lastname: Amstalden
authors.affiliation: Animal Reproduction LaboratoryTexas A&M AgriLife Research Station, 3507 Highway 59E, Beeville, Texas 78102, USADepartment of Animal ScienceKleberg Center, Texas A&M University, College Station, Texas 77843, USADivision of Animal SciencesAnimal Science Research Center, University of Missouri, Columbia, Missouri 65211, USA Animal Reproduction LaboratoryTexas A&M AgriLife Research Station, 3507 Highway 59E, Beeville, Texas 78102, USADepartment of Animal ScienceKleberg Center, Texas A&M University, College Station, Texas 77843, USADivision of Animal SciencesAnimal Science Research Center, University of Missouri, Columbia, Missouri 65211, USA glwilliams@tamu.edu.
authors.forename: Gary L
authors.initials: GL
authors.lastname: Williams
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena / Q000502:physiology*; D000818:Animals; D001835:Body Weight / Q000502:physiology; D002417:Cattle; D004032:Diet; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000134:cerebrospinal fluid; D007031:Hypothalamus / Q000378:metabolism; D020738:Leptin / Q000097:blood*; D007986:Luteinizing Hormone / Q000097:blood; D009478:Neuropeptide Y / Q000134:cerebrospinal fluid* / Q000378:metabolism; D011863:Radioimmunoassay / Q000379:methods; D012741:Sexual Maturation / Q000502:physiology*; D013997:Time Factors; D014886:Weaning
chemical_list: D020738:Leptin; D009478:Neuropeptide Y; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone
keywords: cerebrospinal fluid; heifers; neuropeptide Y; nutritional programing; puberty