Fig. 4

Scatchard analysis of specific ¹²⁵I-Mel binding to cell lysates prepared from NIH3T3 cells stably expressing either rat MT1 or MT2. a ¹²⁵I-Mel saturation binding to rat MT1 or MT2 in NIH3T3 cells. Cell lysates were incubated with various concentrations of ¹²⁵I-Mel (1–200 pM). Non-specific binding was measured in the presence of 20 μM melatonin. Specific ¹²⁵I-Mel binding is defined as total binding minus non-specific binding. b Scatchard plots of saturation binding to rat MT1 and MT2. The K _d, B _max, and Hill’s values depicted are 67.6 pM, 26.5 fmol/mg of whole cell protein, and 1.01 for rat MT1, and 66.7 pM, 27.2 fmol/mg, and 1.01 for rat MT2, respectively. Data shown are representative of four experiments. The K _d, B _max, and Hill’s values of four experiments are 73.2 ± 9.0 pM (mean ± SEM), 27.1 ± 2.7 fmol/mg, and 1.01 ± 0.02 for rat MT1, and 73.7 ± 2.9 pM, 30.0 ± 2.4 fmol/mg, and 1.00 ± 0.01 for rat MT2, respectively