| Summary: | 碩士 === 國立成功大學 === 環境工程學系 === 103 === Endocrine disrupting compounds present in the aquatic environment could cause side effect on aquatic organisms. Previous studies have focused on estrogenic and androgenic compounds in the environment. However, natural and synthetic (anti)glucocorticoids and (anti)mineralocorticoids which are frequently used as pharmaceuticals to treat various symptoms of human diseases can also be released into the aquatic environment.
In this study, recombinant yeast bioassays were used to detect mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) disrupting activities in water and suspended solids (SS) samples collected from 9 Taiwanese rivers. Also, liquid chromatography tandem mass spectrometry (LC-MS/MS) was used to quantify potential MR and GR disrupting chemicals in the aquatic environment in Taiwan.
Bioassays results showed that no MR and GR agonist activities were detected in river samples. In contrast, MR antagonist activity was detected in water and SS samples of all target rivers (〈66.8~4324.0 and 〈66.8~1151.8 SPL-EQ ng/L, respectively), and most of the water and SS samples showed GR antagonist activity as well (〈21.8~94.4 and 〈21.8~106.9 TeCBPA-EQ μg/L, respectively). Several endocrine disrupting chemicals, including testosterone (T), dihydrotestosterone (DHT), nonylphenol (NP), triclosan (TCS), triclocarban (TCC), bisphenol A (BPA) and its chlorinated derivatives, were tested for MR and GR agonist/antagonist activities using bioassays. TCS, TCC and chlorinated BPA derivatives were identified as new MR antagonists in addition to the known MR antagonists BPA, DHT, T and NP. Also, T, DHT, TCS and chlorinated BPA derivatives were reported as new GR antagonists in this study.
LC-MS/MS results showed that DHT (ND~1221.5 ng/L), T (ND~93.2 ng/L), progesterone (ND~34.2 ng/L), dexamethasone (ND~98.2 ng/L), 6-α-prednisolone (ND~38.5 ng/L), fludrocortisone acetate (ND~44.9 ng/L), BPA (23.2~19288.1 ng/L), CBPA (〈0.69~364.7 ng/L), DCBPA (ND~1251.0 ng/L), TrCBPA (ND~153.9 ng/L), TeCBPA (ND~101.9 ng/L), NP (〈2.78~1123.4 ng/L),TCS (ND~204.4) and TCC (ND~292.3 ng/L) were often detected in the water samples from target rivers. However, bioassay-derived MR/GR antagonist activities were several times higher than the activities estimated by LC-MS/MS results, which might be due to the unknown MR and GR antagonists in samples.
In summary, this study revealed the occurrence of MR and GR antagonist activities in Taiwanese rivers and identified several new MR and GR antagonists. The combined effects of MR and GR antagonists and the unknown MR and GR disrupting chemicals in the aquatic environment should be taken for concern in future study.
|
|---|
