Department of Veterinary Sciences and Technologies for Food Safety, University of Milan, Via Celoria 10, 20133 Milan, Italy.
Steroids. 2011 Jan;76(1-2):104-10. doi: 10.1016/j.steroids.2010.09.005. Epub 2010 Sep 24.
After a two-year period of the frequent detection of prednisolone-positive bovine urine samples in the Italian region of Lombardy, studies were initiated to investigate the source. Because the majority of positive samples were detected at the slaughterhouse, researchers hypothesised that, together with increased cortisol and cortisone, a small quantity of prednisolone could be produced by the cows in stressful situations. In the present study, three dairy cows underwent intramuscular treatments with tetracosactide hexaacetate, a synthetic analogue of adrenocorticotropic hormone, to simulate stress. The animals were slaughtered at the end of the study. The results indicated that prednisolone could be detected occasionally in the non-stressful state, but was consistently found in the urine of stressed cows (concentrations ranged from 1.01 to 4.08 ng/mL). To confirm the stress condition, urinary cortisol and cortisone were also detected at high concentrations in the urine, typically at concentrations of hundreds of nanograms per millilitre. The results of this preliminary study did not reveal the metabolic pathway responsible for prednisolone but suggested that this corticosteroid could be produced endogenously.
在意大利伦巴第地区连续两年频繁检测到含有泼尼松龙的牛尿样本后，开展了相关研究以调查其来源。由于大多数阳性样本都是在屠宰场检测到的，研究人员推测，在应激状态下，奶牛可能会产生少量的皮质醇和可的松，以及少量的泼尼松龙。在本研究中，三头奶牛接受了肌内注射促肾上腺皮质激素释放激素六乙酸酯（一种促肾上腺皮质激素的合成类似物）的治疗，以模拟应激。研究结束时对这些动物进行了屠宰。结果表明，泼尼松龙偶尔在非应激状态下可被检测到，但在应激奶牛的尿液中始终可被检测到（浓度范围为 1.01 至 4.08 纳克/毫升）。为了确认应激状态，尿液中的皮质醇和可的松也被检测到了高浓度，通常每毫升数百纳克。这项初步研究的结果并未揭示导致泼尼松龙产生的代谢途径，但表明这种皮质类固醇可能是内源性产生的。
