A high affinity polyclonal antibody-based enzyme linked immunosorbent assay (ELISA) was developed for the quantification of zeranol in bovine urine. On the basis of urine matrix studies, the optimized dilution factors producing insignificant matrix interference were selected as 1:5 in pretreatment. In the improved ELISA, the linear response range was between 0.02 and 1 microg/ml, and the detection limit was 0.02 microg/ml for the assay. The overall recoveries and the coefficients of variation (CVs) were in the range of 82% to approximately 127% and 3.5% to approximately 8.8%, respectively. Thirty-six bovine urine samples spiked with zeranol (ranging from 0.2 to 10 microg/ml) were detected by the ELISA and liquid chromatography (LC) method, and good correlations were obtained between the two methods (R(2)=0.9643). We conclude that this improved ELISA is suitable tool for a mass zeranol screening and can be an alternative for the conventional LC method for zeranol in bovine urine.
Animals ; Calibration ; Cattle ; Chromatography, High Pressure Liquid ; Enzyme-Linked Immunosorbent Assay ; methods ; Indicator Dilution Techniques ; Zeranol ; immunology ; urine

OBJECTIVETo study the effects of phytoestrogen alpha-zearalanol (alpha-ZAL) on normal human breast.

METHODSTen specimens of normal human breast tissues were subcutaneously implanted into 30 athymic nude mice aged 9-10 weeks, one for 3 mice. These mice were then randomly divided into three groups: control group (without hormone treatment, n = 10), 1 mg/kg alpha-ZAL group (n = 10), and 5 mg/kg alpha-ZAL group (n = 10). All breast tissues were taken out 6 weeks later. Immunohistochemistry was used to determine the protein expressions of proliferating cell nuclear antigen (PCNA), inhibiting apoptosis gene Bcl-2, estrogen receptor (ER), and progesterone receptor (PR). Reverse transcription polymerase chain reaction (RT-PCR) was used to measure the expression levels of estrogen sulfotransferase (EST) mRNA and bridging integrator protein-1 (BIN1) mRNA. Morphological features of grafts before and after treatment were also observed.

RESULTSAlpha-ZAL had no significant effects on Bcl-2, PCNA, ER, and PR expression of mammary epithelial cells in graft specimens. Alpha-ZAL upregulated BIN1 mRNA expression in grafts, but had no significant effect on ESTmRNA expression.

CONCLUSIONSAlpha-ZAL does not affect the morphology, proliferating, and apoptosis of epithelial cells in normal human breast tissues implanted into nude mice, but it may increase the gene expression of tumor-inhibiting BIN1, suggesting that alpha-ZAL may have potential proteotive effect on normal human breast.

Adult ; Animals ; Breast ; chemistry ; drug effects ; Estrogens, Non-Steroidal ; pharmacology ; Female ; Humans ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Phytoestrogens ; pharmacology ; Proliferating Cell Nuclear Antigen ; analysis ; Random Allocation ; Receptors, Estrogen ; analysis ; Receptors, Progesterone ; analysis ; Zeranol ; pharmacology

OBJECTIVETo investigate the effect of alpha-zearalenol on angiotensin II-induced beta3 integrin mRNA expression in human umbilical vein endothelial cells (HUVECs).

METHODSThe mRNA level in integrin beta3 was determined by reverse transcription-polymerase chain reaction. Endothelial NF-kappaB activity was determined by the luciferase activity assay of plasmid NF-kappaB-LUC.

RESULTSThe angiotensin II-induced beta3 integrin mRNA expression was inhibited by alpha-zearalenol and 17beta-estradiol (10 nmol/L -1 micromol/L), but not influenced by ICI 182, 780, a pure competitive antagonist for estrogen receptor or a nitric oxide inhibitor Nomega-Nitro-L-arginine methyl ester hydrochloride. Alpha-zearalenol and 17beta-estradiol suppressed the angiotensin II-induced activation of NF-kappaB in endothelial cells.

CONCLUSIONAlpha-zearalenol inhibits angiotensin II-induced integrin beta3 mRNA expression by suppressing NF-kappaB activation in endothelial cells.

Angiotensin II ; antagonists & inhibitors ; Cells, Cultured ; Endothelial Cells ; drug effects ; metabolism ; Endothelium, Vascular ; drug effects ; metabolism ; Estradiol ; pharmacology ; Female ; Gene Expression Regulation ; Humans ; Integrin beta3 ; biosynthesis ; genetics ; NF-kappa B ; antagonists & inhibitors ; physiology ; Nitric Oxide ; antagonists & inhibitors ; Phytoestrogens ; pharmacology ; RNA, Messenger ; metabolism ; Receptors, Estrogen ; antagonists & inhibitors ; Zeranol ; analogs & derivatives ; pharmacology