title: Determination of plasma melatonin levels by enzyme-linked immunosorbent assay (EIA) in turbot (Scophtalmus maximus L.) and tench (Tinca tinca L.).
abstract: An enzymoimmunoassay (EIA) kit for plasma melatonin (MLT) measurements was employed in tench (Tinca tinca) and in turbot (Scophtalmus maximus). Tench and turbot plasma samples were purified with a C18 reversed phase extraction columns because this kit is designed for human serum measurements. The lowest detection limit of the technique was 11.48 pg/well with a sensitivity at 50% binding of 100 pg/well. Intra-assay and inter-assay CV (%) were always less than 5% (n=8), and 9% (n=6) in tench plasma samples, and less than 5% (n=8) and 13% (n=5) in turbot plasma samples, respectively. Correlation coefficients between EIA and RIA measurements in tench and turbot plasma samples were 0.93 and 0.89 (p<0.001) respectively. Diurnal and nocturnal plasma melatonin mean levels were 14.7+/-2.1 pg/ml and 87.4+/-11 pg/ml in tench (n=15), and 3.5+/-0.4 pg/ml and 28.1+/-2.1 pg/ml in turbot (n=15). These species showed a melatonin circadian rhythm as in other animals studied. The results suggest that the commercial kit used in this experiment could be a suitable and alternative method to RIA for plasma MLT determinations in tench and turbot although it is necessary to increase volumes (1ml) and concentrate daytime samples.
authors.affiliation: Depto. de Producción Animal, E.T.S.I. Agrónomos, Universidad Politécnica, Madrid, Spain. prebollar@pan.etsia.upm.es
authors.forename: P G
authors.initials: PG
authors.lastname: Rebollar
authors.forename: E
authors.initials: E
authors.lastname: Ubilla
authors.forename: J B
authors.initials: JB
authors.lastname: Peleteiro
authors.forename: M T
authors.initials: MT
authors.lastname: Agapito
authors.forename: J M
authors.initials: JM
authors.lastname: Alvariño
mesh_terms: D000818:Animals; D003530:Cyprinidae / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods* / Q000706:statistics & numerical data; D005069:Evaluation Studies as Topic; D005412:Flatfishes / Q000097:blood*; D006801:Humans; D008550:Melatonin / Q000097:blood*; D011863:Radioimmunoassay / Q000379:methods / Q000706:statistics & numerical data; D012680:Sensitivity and Specificity
chemical_list: D008550:Melatonin