ABSTRACT
To investigate the potential toxic effects and mechanisms of Tris(1; 3-dichloro-2-propyl) phosphate (TDCIPP) on thyroid in female SD rats. Thirty-two 3-weeks-old female SD rats were randomly divided into normal group(treated with corn oil ), and low/moderate/high-dose group treated with TDCIPP (dissolved in corn oil )(n=8). All rats were treated with corn oil or TDCIPP (50, 100, 250 mg/(kg·d)) once a day during a 21-day period. All rats were sacrificed after the last administration. Serum thyroid stimulating hormone (TSH), 3,3',5-triiodothyronine (T3), 3,3',5,5'-tetraiodothyronine (T4), free 3,3',5,5'-tetraiodothyronine (FT4) were detected with ELISA kit. Morphology of thyroid was observed with hematoxylin and eosin (HE) staining. Expressions of genes and proteins correlate with thyroid were measured respectively by real-time fluorescence quantitative PCR and Western blot. Compared with control group, morphology of thyroid showed follicles irregular arrangement, hypocolloid, and follicular hyperplasia in TDCIPP treatment groups. The levels of serum TSH in low-dose TDCIPP group and T3 in high-dose TDCIPP group were significantly higher than those in control group(P＜0.05). Thyroid stimulating hormone receptor (TSHR) mRNA expression was decreased distinctly in low-dose TDCIPP group, while the expression of thyroperoxidase (TPO) mRNA was increased notably in moderate and high-dose TDCIPP groups(P＜0.05,P＜0.01). Compared with control group, the level of TRβ protein was decreased significantly in moderate and high-dose TDCIPP groups, while the expressions of udp-glucuronosyl-transferases (UGTs) and cytochrome-p450-3A1 (CYP3A1) proteins were upregulated notably in TDCIPP treatment groups(P＜0.05). Treated with 50 mg/(kg·d) TDCIPP can cause thyroid hyperplasia, change the levels of thyroid hormones, and disturb thyroid function, therefore, it has toxic effects on the thyroid.
ABSTRACT
A sensing system based on AuNP-AuNP-UCNP triple structure for efficient detection of dual targets was constructed. In the preparation of triple structure, the gold nanoparticles (AuNPs) and upconversion nanoparticles (NaYF4: Yb, Er, Gd, UCNPs) were synthesized and surface modified. Then the two nanoparticles and their aptamers were connected to form two kinds of optical fluorescent probes. A nucleic acid sequence that matches with two aptamers was designed, rendering the probes to get close based on the principle of complementary base pairing. On the basis of this, a sensing system with a triple structure was prepared,and its connecting effect was characterized by TEM. With this system, dual targets of bisphenol A and estradiol were efficiently and conveniently detected through quantitative determination by fluorescence and UV spectrophotometer. At reaction temperature of 30℃ and pH=7.8,this method exhibited good linear range for determination of bisphenol A and estradiol from 2 ng/mL to 200 ng/mL and from 10 ng/mL to 150 ng/mL, with limits of detection of 0.2 ng/mL and 0.5 ng/mL, respectively. This sensing system with the triple structure owned better specificity to structural and functional analogues, and showed good repeatability and stability. What's more,this sensing system was applied in actual water detection,with the recoveries between 86.1% and 107. 4%, and the relative standard deviation below 6. 8%. This method showed promising applications in other environmental estrogens in water samples.