Reference

Development of immunoaffinity sample-purification for GC-MS analysis of ractopamine in swine tissue

All Rights Reserved. Development of immunoaffinity sample-purification for GC-MS analysis of ractopamine in swine tissue. Wang, J. P.In this study，97825-25-7 is also used.; Li, X. W.; Zhang, W.; Shen, J. Z. (Department of Pharmacology and Toxicology, College of Veterinary Medicine, China Agricultural University, Beijing 100094, Peop. Rep. China). Chromatographia, 64(9-10), 613-617 (English) 2006 Vieweg Verlag/GWV Fachverlage GmbH. CODEN: CHRGB7. ISSN: 0009-5893. DOCUMENT TYPE: Journal CA Section: 17 (Food and Feed Chemistry) A method combining immunoaffinity chromatog. with gas chromatog.-mass spectrometry (GC-MS) has been established for detn. of ractopamine residues in swine liver and urine. After clean-up on an immunoaffinity chromatog. column, GC-MS anal. revealed recovery from blank swine liver and urine fortified at 2.5-20 ng g-1 (ng mL-1 for urine), resp., was 68.2-78.6 and 76.2-83.1%. The limits of detection and quantification were 0.5 ng g-1 (or ng mL-1) and 2.0 ng g-1 (or ng mL-1), resp. The procedure was used for anal. of ractopamine residues in samples of swine liver and urine in which the levels were unknown. The amts. detected were 9-216 ng g-1 (ng mL-1). .

The impact of feeding b2-adrenergic agonists on rainbow trout muscle b2-adrenoceptors and protein synthesis

The impact of feeding b2-adrenergic agonists on rainbow trout muscle b2-adrenoceptors and protein synthesis. Lortie, M. B.; Arnason, T.; Dugan, S. G.; Nickerson, J. G.; Moon, T. W. ( Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Can.). Journal of Fish Biology, 65(3), 769-787 (English) 2004 Blackwell Publishing Ltd. CODEN: JFIBA9. ISSN: 0022-1112. DOCUMENT TYPE: Journal CA Section: 18 (Animal Nutrition) The b2-adrenergic agonists (b2-AAs) clenbuterol (CLEN) and ractopamine (RACT) were fed to rainbow trout Oncorhynchus mykiss for 30-37 days and red and white muscle b2-adrenoceptor (b2-AR) binding characteristics and mRNA expression were assessed in parallel with fractional protein synthetic rates. Feeding CLEN or RACT had no significant effect on any body or physiol. variables measured. There were no significant differences in the no. of binding sites (Bmax) while a significant increase in the Kd was obsd. for the b-ARs of red and white muscle membranes isolated from b2-AA-fed rainbow trout. No change in b2-AR mRNA levels was obsd. with b2-AA feeding, implying that these b2-AAs do not act at the transcriptional level at least for the b2-AR. The b2-AA treatments, however, did significantly increase red and white muscle fractional protein synthesis rates in whole protein, myofibrillar protein and sarcoplasmic sol. 97825-25-7 and 37148-27-9 are just another two chemicals used in this study. protein fractions. Although not conclusive, this study supports a direct link between rainbow trout muscle b2-ARs and muscle protein synthesis. .