[Organ-Specific Accumulation and Toxicokinetics of Ephedrine in Adult Zebrafish (Danio rerio)]

Ephedrine (EPH) is an alkaloid commonly used to relieve nasal congestion caused by colds, allergic rhinitis, rhinitis, and sinusitis, and to control bronchial asthma. It is also be used as a raw material in the manufacture of methamphetamine. Although the distribution of EPH in surface waters has been widely studied, its uptake, internal distribution, and toxicokinetic processing in exposed organisms have not been well investigated. In this study, we investigated the uptake, disposition, and toxicokinetics of EPH in zebrafish (Danio rerio) in a semi-static exposure system. EPH was consistently detected in zebrafish biological samples, with the highest concentrations of 84.97 ng·g^-1 detected in the brain tissue of fish in the high treatment group. Over the 14-d exposure period, the relative abundance of mean concentrations of EPH in biological samples generally followed the order of brain > ovary > liver > intestine > muscle. The uptake rate constants (K_u), elimination rate constants (K_e), and half-lives of EPH in the biological tissues were in the ranges 0.23-570.31 L·(kg·d)^-1, 1.22-6.11 d^-1, and 0.12-0.57 d, respectively. The observed bioconcentration factor (BCF_o) and kinetically-derived bioconcentration factor (BCF_k) were similar, ranging 0.24-337.33 L·kg^-1 and 0.13-316.43 L·kg^-1, respectively. These results are helpful for understanding the behavior of psychoactive substances in aquatic organisms and have directive significance for studying their toxicity and ecological risks to aquatic organisms.