title: 5-HT receptor subtypes as key targets in mediating pigment dispersion within melanophores of teleost, Oreochromis mossambicus.
abstract: The presence of distinct class of 5-HT receptors in the melanophores of tilapia (Oreochromis mossambicus) is reported. The cellular responses to 5-HT (5-hydroxytryptamine), 5-HT(1), and 5-HT(2), agonists on isolated scale melanophores were observed with regard to pigment translocation within the cells. It was found that 5-HT exerted rapid and strong concentration dependent pigment granule dispersion within the melanophores. The threshold pharmacological dose of 5-HT that could elicit a measurable response was as low as 4.7×10(-12) M/L. Selective 5-HT(1) and 5-HT(2) agonists, sumatriptan and myristicin were investigated and resulted in dose-dependent pigment dispersion. The dispersing effects were effectively antagonized by receptor specific antagonists. It is suggested that 5-HT-induced physiological effects are mediated via distinct classes of receptors that possibly participate in modulation of pigmentary responses of the fish.
authors.affiliation: Department of Biotechnology, Saifia College of Science, Bhopal, MP, India.
authors.forename: Saima
authors.initials: S
authors.lastname: Salim
authors.forename: Ayesha S
authors.initials: AS
authors.lastname: Ali
authors.forename: Sharique A
authors.initials: SA
authors.lastname: Ali
mesh_terms: D000081248:Allylbenzene Derivatives; D000818:Animals; D001593:Benzyl Compounds / Q000494:pharmacology; D004148:Dioxolanes / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D029941:Fish Proteins / Q000378:metabolism*; D005473:Fluoxetine / Q000494:pharmacology; D008543:Melanins; D008547:Melanophores / Q000187:drug effects / Q000378:metabolism*; D008711:Metergoline / Q000494:pharmacology; D010860:Pigments, Biological / Q000378:metabolism*; D011748:Pyrogallol / Q000031:analogs & derivatives / Q000494:pharmacology; D011985:Receptors, Serotonin / Q000378:metabolism*; D012701:Serotonin / Q000494:pharmacology; D058825:Serotonin 5-HT1 Receptor Agonists / Q000494:pharmacology; D058829:Serotonin 5-HT1 Receptor Antagonists / Q000494:pharmacology; D058826:Serotonin 5-HT2 Receptor Agonists / Q000494:pharmacology; D058830:Serotonin 5-HT2 Receptor Antagonists / Q000494:pharmacology; D018170:Sumatriptan / Q000494:pharmacology; D017210:Tilapia / Q000378:metabolism*; D014196:Trazodone / Q000494:pharmacology; D015016:Yohimbine / Q000494:pharmacology
chemical_list: D000081248:Allylbenzene Derivatives; D001593:Benzyl Compounds; D004148:Dioxolanes; D029941:Fish Proteins; D008543:Melanins; D010860:Pigments, Biological; D011985:Receptors, Serotonin; D058825:Serotonin 5-HT1 Receptor Agonists; D058829:Serotonin 5-HT1 Receptor Antagonists; D058826:Serotonin 5-HT2 Receptor Agonists; D058830:Serotonin 5-HT2 Receptor Antagonists; D005473:Fluoxetine; D011748:Pyrogallol; C005246:myristicin; D008711:Metergoline; D015016:Yohimbine; D012701:Serotonin; D018170:Sumatriptan; D014196:Trazodone