Development of an Enzyme-linked Immunosorbent Assay Using Vitellin for Vitellogenin Measurement in the Pale Chub, Zacco platypus

OBJECTIVES: Fish vitellogenin (VTG) is produced in the female liver during oogenesis through the estradiol cycle and produced in the male liver by endocrine disrupting chemicals (EDCs) such as alkylphenols. In this study, we propose that the VTG concentration in the pale chub could be detected using monoclonal antibodies and polyclonal antibodies against vitellin (Vn) in a VTG enzyme-linked immunosorbent assay (ELISA) system. METHODS: Monoclonal antibodies and polyclonal antibodies were produced using the Vn extracted from the matured ovum of the ovary. The VTG was extracted from the plasma of the male pale chub. The Vn and VTG were confirmed by measuring the molecular weight of their proteins using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and the specificity of the antibodies was checked through western blotting methods. The assay system was validated with respect to optimal assay concentrations, specificity, recovery, and intra- and inter-assay variations. RESULTS: The Vn consisted of two protein bands with apparent molecular weights of 64 and 37 kDa. The SDS-PAGE indicated protein weights of 146 and 77 kDa in the VTG. The assay range was 15.6 ng/mL to 2,000 ng/mL, and the value of the intra- and inter-assay variations were within 10.0% and 14.7%, respectively. The recovery rate was 99.5+/-5.5%. CONCLUSIONS: A sandwich ELISA was developed that could be used to qualify the VTG of pale chub in screening for EDCs. Pale chub is an ideal species for observing estrogen activity in the environment because of its extensive habitat and extensive food chain. The ELISA developed here would be more favorable than those for other species for determining the effect of long-term food chain accumulation of EDCs in aquatic environments.

The Effect of IP3 Receptor Inhibition Using 2-APB on Gentamicin Ototoxicity in Cochlear Sensory Cell / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Elevated intracellular calcium level is known to play important roles in the apoptotic pathway. IP3 receptor (ligand-gated channels that release Ca2+ from intracellular stores) is emerging as a key site for regulation of apoptosis. 2-Aminoethoxydiphenyl borate (2-APB) is one of the reliable IP3 receptor antagonists. We examined the effect of 2-APB on gentamicin ototoxicity in vitro, using the HEI-OC1 cell line. MATERIALS AND METHOD: HEI-OC1 cells were trWWeated with 100micrometer gentamicin. Using a CaspACE assay, we measured the caspases-3 activity in the gentamicin treated hair cells with and without 2-APB pre-incubation. We also observed intra-cellular calcium concentrations in HEI-OC1 cells using a confocal microscopy (calcium green-1 stain). Live cell imaging was performed by using fluorescence video-time lapse system. RESULTS: Cytosolic calcium elevation by gentamicin was remarkably inhibited by 2-APB. Caspases-3 activities of gentamicin treated cells were higher than those of the control. After incubation with 2-APB, caspases-3 activities and cell death of gentamicin treated cells were shown to decrease. CONCLUSION: 2-APB reduces Caspases-3 activity in the gentamicin treated HEI-OC1 cells by inhibition of cytosolic calcium increase.