title: [3H]serotonin binds to two classes of sites in Drosophila head homogenate.
abstract: [3H]serotonin binds to two classes of sites in a crude membrane preparation of Drosophila melanogaster heads, with apparent Kd values of 1.4 and 130 nM, and a concentration of 0.2 and 1.5 pmol/mg protein, respectively. High salt concentration and a guanyl nucleotide decrease the number of the high-affinity binding sites. Low concentrations of ergot alkaloids, various tryptamine derivatives, neuroleptic drugs, but not of phentholamine , propranolol and dopamine, displace [3H]serotonin from its high affinity sites. The relevance of the [3H]serotonin-binding sites to serotonin receptors in Drosophila is discussed.
mesh_terms: D000818:Animals; D003902:Detergents / Q000494:pharmacology; D004331:Drosophila melanogaster / Q000378:metabolism*; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D006257:Head / Q000378:metabolism; D066298:In Vitro Techniques; D009994:Osmolar Concentration; D011985:Receptors, Serotonin / Q000187:drug effects; D012701:Serotonin / Q000378:metabolism*
chemical_list: D003902:Detergents; D011985:Receptors, Serotonin; D012701:Serotonin; D006165:Guanylyl Imidodiphosphate