Determination of plasma melatonin levels by enzyme-linked inmunoabsobent assay (EIA) in turbot (Scophthalmus maximus L.) and tench (Tinca tinca L.)

• Main Authors: Rebollar, P.J., Ubilla, E., Peleteiro-Alonso, J.B. (José Benito), Alvariño, M.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Centro Oceanográfico de Vigo 1999
• Subjects: Eia; Scophthalmus maximus; Turbot
• Online Access: http://hdl.handle.net/10508/6915

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. 1