Abstract
Previous studies have found that melatonin was related to the growth and development in avian. Therefore, the newly hatched broilers were exposed to colors of light to establish a model of pinealectomy and explored the mechanism of pineal melatonin promoting growth hormone (GH) secretion. The results showed that green light (GL) promoted the levelsof GH, pituitary-specific transcription factor-1 (Pit-1) genes and proteins in pituitary. Moreover, the mRNA and proteinlevels of melatonin receptor subtypes Mel1b and Mel1c in the pituitary in GL were higher than other monochromatic light groups. After pinealectomy, the expression of Pit-1, GH, Mel1b and Mel1c in pituitary decreased. In vitro, exogenous melatonin promoted the level of Pit-1 mRNA and the secretion of GH in anterior pituitary cells. However, when melatonin was added with exogenous selective Mel1b antagonist (4-phenyl-2-propionamideotetralin) and selective Mel1c antagonist (prazosin), the levelof Pit-1 mRNA and the GH secretion decreased. When selective Mel1b and Mel1c antagonists were added simultaneously, the decrease in Pit-1 mRNA and GH secretion was more significant. These results indicated that pineal melatonin promotes the expression of Pit-1 under GL by binding to melatonin receptor subtypes Mel1b and Mel1c in the pituitary, thereby increasing GH secretion and promoting the growth.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.