title: Melatonin Mediates Monochromatic Light-induced Insulin-like Growth Factor 1 Secretion of Chick Liver: Involvement of Membrane Receptors.
abstract: Monochromatic lights influenced the proliferation and differentiation of skeletal satellite cells in broilers by the enhancement of insulin-like growth factor 1 (IGF-1) secretion. However, whether melatonin (MEL)-mediated monochromatic lights influenced the IGF-1 secretion remains unclear. Newly hatched broilers, including intact, sham operation and pinealectomy groups, were exposed to blue (BL), green (GL), red (RL) and white light (WL) from a light-emitting diode system for 14 days. The results showed that GL effectively promoted the secretion of MEL and IGF-1, the expression of proliferating cell nuclear antigen and MEL receptor subtypes Mel1a, Mel1b and Mel1c in the liver compared to BL and RL in vivo. Moreover, those was a positive correlation between MEL and IGF-1 (r = 0.834). After pinealectomy, however, these parameters declined, and there were no differences between GL and other monochromatic light treatments. In vitro, exogenous MEL increased hepatocyte proliferation and IGF-1 secretion. Meanwhile, the MEL enhancements were suppressed by prazosin (selective Mel1c antagonist), followed by luzindole (nonselective Mel1a/Mel1b antagonist), but not suppressed by 4-phenyl-2-propionamideotetralin (selective Mel1b antagonist). These findings demonstrated that MEL mediated the monochromatic light-induced secretion of IGF-1 in chicks' livers by Mel1c and that Mel1a may be involved in this process.
authors.affiliation: Laboratory of Anatomy of Domestic Animal, College of Animal Medicine, China Agricultural University, Beijing, China.
authors.forename: Suqi
authors.initials: S
authors.lastname: Li
authors.affiliation: Laboratory of Anatomy of Domestic Animal, College of Animal Medicine, China Agricultural University, Beijing, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Cao
authors.affiliation: Laboratory of Anatomy of Domestic Animal, College of Animal Medicine, China Agricultural University, Beijing, China.
authors.forename: Zixu
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Laboratory of Anatomy of Domestic Animal, College of Animal Medicine, China Agricultural University, Beijing, China.
authors.forename: Yulan
authors.initials: Y
authors.lastname: Dong
authors.affiliation: Department of Animal Husbandry and Veterinary, Beijing Vocational College of Agriculture, Beijing, China.
authors.forename: Wenli
authors.initials: W
authors.lastname: Wang
authors.affiliation: Laboratory of Anatomy of Domestic Animal, College of Animal Medicine, China Agricultural University, Beijing, China.
authors.forename: Yaoxing
authors.initials: Y
authors.lastname: Chen
mesh_terms: D000818:Animals; D049109:Cell Proliferation / Q000528:radiation effects; D002645:Chickens; D003116:Color; D005786:Gene Expression Regulation / Q000528:radiation effects*; D022781:Hepatocytes / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000378:metabolism*; D008027:Light; D008099:Liver / Q000378:metabolism* / Q000528:radiation effects; D008297:Male; D008550:Melatonin / Q000097:blood / Q000378:metabolism*; D010870:Pineal Gland / Q000378:metabolism / Q000601:surgery; D018809:Proliferating Cell Nuclear Antigen / Q000235:genetics / Q000378:metabolism; D044094:Receptors, Melatonin / Q000235:genetics / Q000378:metabolism
chemical_list: D018809:Proliferating Cell Nuclear Antigen; D044094:Receptors, Melatonin; D007334:Insulin-Like Growth Factor I; D008550:Melatonin