title: Melatonin receptor subtypes Mel1a and Mel1c but not Mel1b are associated with monochromatic light-induced B-lymphocyte proliferation in broilers.
abstract: This study determined the effects of melatonin (MEL) and its receptors on monochromatic light-induced bursal B-lymphocyte proliferation in broiler chickens. In vivo, green light (GL) enhanced the proliferation of B lymphocytes in bursas by 16.49% to 30.83% and the expression of MEL receptor subtypes 1a (Mel1a), Mel1b, and Mel1c receptors in bursas by 6.91% to 366.98% than other light colors. However, pinealectomy reduced these parameters and eliminated the differences between GL and other light groups. In vitro, the MEL-induced bursal B-lymphocyte proliferation was most suppressed by prazosin (P = 0.001, selective Mel1c antagonist), followed by luzindole (P = 0.022, nonselective Mel1a/Mel1b antagonist), but not by 4-phenyl-2-propionamideotetralin (P = 0.144, selective Mel1b antagonist). Similarly, dibutyryl-cyclic adenosine monophosphate (cAMP; analog of cAMP; P = 0.017) but not 8-(4-chloro-phenylthio)-2'-O-methyladenosine-3',5'-cyclic monophosphate (P = 0.736; activator of exchange protein directly activated by cAMP) significantly inhibited bursal B-lymphocyte proliferation. These results suggest that MEL mediates GL-induced bursal B-lymphocyte proliferation through Mel1c and Mel1a receptors but not Mel1b receptors by activating the cAMP/protein kinase A pathway.
authors.affiliation: Laboratory of Anatomy of Domestic Animals, College of Animal Medicine, China Agricultural University, Haidian, Beijing 100193, China.
authors.forename: J
authors.initials: J
authors.lastname: Li
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.forename: J
authors.initials: J
authors.lastname: Cao
authors.forename: Y
authors.initials: Y
authors.lastname: Dong
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000528:radiation effects*; D003994:Bucladesine / Q000494:pharmacology; D002060:Bursa of Fabricius / Q000737:chemistry; D049109:Cell Proliferation / Q000528:radiation effects*; D002645:Chickens / Q000276:immunology*; D000242:Cyclic AMP / Q000502:physiology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000502:physiology; D003992:Dibucaine; D008027:Light; D008550:Melatonin / Q000502:physiology*; D011224:Prazosin / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D044094:Receptors, Melatonin / Q000235:genetics / Q000502:physiology*; D014363:Tryptamines / Q000494:pharmacology
chemical_list: D012333:RNA, Messenger; D044094:Receptors, Melatonin; D014363:Tryptamines; C057154:luzindole; D003994:Bucladesine; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D008550:Melatonin; D003992:Dibucaine; D011224:Prazosin
keywords: B lymphocyte; Bursa of fabricius; Melatonin; Melatonin receptor; Monochromatic light