title: Single injection of the β2-adrenergic receptor agonist, clenbuterol, into newly hatched chicks alters abdominal fat pad mass in growing birds.
abstract: Excessive energy is stored in white adipose tissue as triacylglycerols in birds as well as in mammals. Although β2-adrenergic receptor agonists reduce adipose tissue mass in birds, the underlying mechanism remains unclear. The aim of the current study was to examine the effects of a single intraperitoneal injection of the β2-adrenergic receptor agonist, clenbuterol, on the abdominal fat pad tissue development. Thirty-three chicks at 1-day-old were given a single intraperitoneal injection of clenbuterol (0.1mg/kg body weight) or phosphate-buffered saline. At 2 weeks post-dose, the weight of the abdominal fat tissue was decreased in the clenbuterol-injected chicks, and small adipocyte-like cells were observed in the abdominal fat pad tissue of the clenbuterol-injected chicks. Then, the expression of mRNAs encoding genes related to avian adipogenesis was examined in the abdominal fat pat tissue. The expression of mRNAs encoding Krüppel-like zinc finger transcription factor 5 (KLF-5), KLF-15, and zinc finger protein 423 in the abdominal fat pad tissue of the clenbuterol-injected chicks was significantly lower (P<0.05) than that of the control chicks, while the expression of mRNA encoding peroxisome proliferator-activated receptor-gamma was not affected. In addition, both mRNA expression (P<0.05) and enzymatic activity (P<0.05) of fatty acid synthase (FAS) were decreased in the abdominal fat pad tissue of the clenbuterol-injected chicks, while clenbuterol injection did not affect FAS activity in liver. These results suggested that a single injection with clenbuterol into newly hatched chicks reduces their abdominal fat pad mass possibly via disrupting adipocyte development during later growth stages.
authors.affiliation: Department of Biochemical Science and Technology, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Ishimaru
authors.affiliation: Department of Biochemical Science and Technology, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan. Electronic address: ijiri@chem.agri.kagoshima-u.ac.jp.
authors.forename: Daichi
authors.initials: D
authors.lastname: Ijiri
authors.affiliation: Department of Biochemical Science and Technology, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan.
authors.forename: Saki
authors.initials: S
authors.lastname: Shimamoto
authors.affiliation: Department of Biochemical Science and Technology, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan.
authors.forename: Kanae
authors.initials: K
authors.lastname: Ishitani
authors.affiliation: Department of Biochemical Science and Technology, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nojima
authors.affiliation: Department of Biochemical Science and Technology, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Ohtsuka
mesh_terms: D050153:Abdominal Fat / Q000187:drug effects / Q000254:growth & development*; D000273:Adipose Tissue / Q000187:drug effects / Q000254:growth & development*; D000318:Adrenergic beta-Agonists / Q000008:administration & dosage* / Q000494:pharmacology*; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002645:Chickens / Q000097:blood / Q000235:genetics / Q000254:growth & development*; D002976:Clenbuterol / Q000008:administration & dosage* / Q000494:pharmacology*; D064429:Fatty Acid Synthases / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009929:Organ Size / Q000187:drug effects; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D000318:Adrenergic beta-Agonists; D012333:RNA, Messenger; D064429:Fatty Acid Synthases; D002976:Clenbuterol
keywords: Adipocytes; Adipose tissue; Chicken; Lipid metabolism; Receptors adrenergic beta-2