ABSTRACT
Objective To determine low-concentration clenbuterol in edible meat based on the solidphase extraction coupled with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).Method The homogenated sample was acidized to remove proteins,and purified using the liquid-liquid extraction and MCX Oasis solid prepared extraction column,then further treated with gradient elution with the mobile phase of ammonium formate (10 mmol/L and pH 3.5) and acetonitrile.The clenbuterol was completely separated on Eclipse C18 (1.8 μm,4.6×100 mm) column and detected in multiple reaction monitoring (MRM) mode.Results A good linearity was achieved for clenbuterol in the arrange of 0.01～0.2 μg/kg based on the internal standard calibration of D9-clenbuterol,with the linearity correlation coefficient greater than 0.99 and the detection limit of 0.005 μg/kg.The relative recovery of target compounds spiked in blank sample at three levels ranging from 78.8 to 114.8％,with the relative standard deviations less than 10％.Conclusion The method in this research is simple,rapid,reliable and suitable to confirm low-concentration clenbuterol in edible meat.
ABSTRACT
Objective To observe the ultrastructure location of Huntingtin-associated protein 1(HAP1) in rat adrenal medulla and the effect of cold stress on the expression of HAP1 in rat adrenal medulla. Methods Fourteen healthy male Wistar rats were used in the present study and among them two rats were used for immune electron microscopy and twelve rats for cold stress experiment. In the cold stress experiment, animals were divided into control and cold groups randomly with six rats in each group. During the experiment, rats were housed in a room at the temperature of 4℃ for 12 hours and then immunohistochemistry and Western blotting were used to measure the expression of HAP1 in adrenal medulla. Results By using the immune electron microscopy, the results showed HAP1 was located on the external membrane of secretory vesicles of adrenal medulla and their membranous organelles. The expression of HAP1 in adrenal medulla of cold group significantly decreased as compared with that of control group ( P <0.01). Conclusion HAP1 might be related with the adrenal medulla cells endocrine granula and involved in the transmission and release of adrenaline or noradrenaline in secretory granule.
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Objective To make a survey of medication taken by Chinese athletes and a comparison between Chinese athletes and athletes from other countries in order to get information about how to improve Chinese athletes' performance. Method The information came from the forms"Doping Control Sample Collection" in which athletes answered the question: "What medications have you taken in the past 3 days?" The medicines taken by athletes were classified and statistically analyzed.Results 2,330 athletes and 25 kinds of sports were involved in. Medicines were statistically analyzed with 4 classes: profiling of declaration, vitamins and minerals, medicines for treatments, alternative medicine. Conclusion The survey recorded the types of supplements and medications taken by athletes in China in 1999. Chinese athletes took less vitamins and more alternative medicines than athletes from other countries.
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Objective To explore the endothelial changes of renal artery of hypertension. diabetes and hypertension in-corpora- tion diabetes rat. Methods The scanning electron microscopy was used in experiment. Results The endothelium of renal artery of normal group were smooth and distinct. The surface of the endothelium were showed irregular and finger prints and red blood cells and mono- cytes adhered to endothelium in hypertensive group.All these changes were more prominent in hypertension incorporation diabetes group, so that the mononuclear cells were migrated into endothelium. Conclusion The endothelium of renal artery of hypertension, diabetes and hypertension incorporation diabetes rats showed abnonmal changes.
ABSTRACT
Objective To investigate the steroid levels of urine in Chinese athletes. Methods Subjects were 1217 Chinese athlete, 8 kinds of steroids named androsterone (An), etiocholanolone (Etio), dihydrotestosterone (DHT), dehydroepiandrosterone (DHET), Testosterone (T), Epitestosterone (ET), 5?-androstane-3?, 17?-diol (5?-diol), 5?-androstane-3?, 17?-diol (5?-diol) were measured by gas chromatography combined with mass spectrometry (GC/MS) after the urine sample being treated with chemical pre-extraction, hydrolysis, extraction and derivatization. Results The urine steroid levels of the Chinese male athlete were higher than those of the female athlete, but both male and female athlete had a lower urine steroids especially testosterone and 5?-androstane-3?,17?-diol, 4～7 times lower than other country's athletes. Some ratios of urine steroids such as An/Etio, T/ET, 5?-diol/5?-diol were relatively steady, which were affected less by gender.