Boldenone ELISA Kit

Although beta-boldenone (bBol) used to be a marker of illegal steroid administration in calves, its endogenous formation has recently been demonstrated in these vertebrates However, research on the pathway leading to bBol remains scarce This study shows the usefulness of in vivo invertebrate models as alternatives to vertebrate animal experiments, using Neomysis integer and Lucilia sericata. In accordance with vertebrates, androstenedione (AED) was the main metabolite of beta-testosterone (bT) produced by these invertebrates, and bBol was also frequently detected Moreover. in vitro experiments using feed-borne fungi and microsomes were useful to perform the pathway from bT to bBol Even the conversion of phytosterols into steroids was shown in vitro Both in vivo and in vitro. the conversion of bT into bBol could be demonstrated in this study. Metabolism of phytosterols by feed-borne fungi may be of particular importance to explain the endogenous bBol-formation by cattle To the best of our knowledge, it is the first time the latter pathway is described in literature (C) 2010 Elsevier Ltd All rights reserved

A novel screening procedure for the sulfate and glucuronide conjugates of testosterone (T) and epitestosterone (E) in human urine was developed based on liquid-solid extraction and microbore high-performance liquid chromatography combined on-line with ion-spray tandem mass spectrometry. Confirmation of the sulfate and glucuronide conjugates of testosterone and epitestosterone isolated from normal human urine was achieved by selected reaction monitoring of characteristic product ions of the parent compounds. Endogenous levels of the steroid conjugates are detected in normal male urine and an increase is observed when the sample is fortified with authentic analytical standards of the conjugates. Calibration curves of all steroid conjugates in urine are linear over a range of twenty. Deuterated internal standards of testosterone glucuronide and epitestosterone sulfate were used for quantitation of the endogenous conjugates. T/E ratios were determined based on the glucuronide fractions of six replicates from a normal male and were shown to be statistically reproducible and below the accepted T/E threshold of 6:1. Sulfate conjugates were shown to be present at significantly lower levels in the urine. The method has potential as an alternative for monitoring anabolic steroid conjugates in human urine.