Ellerbrock R, Canisso I, Feijo L, Lima F, Shipley C, Kline K
Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, USA.
Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, USA.
Theriogenology. 2016 Apr 15;85(7):1219-24. doi: 10.1016/j.theriogenology.2015.12.002. Epub 2015 Dec 17.
Urospermia is known to affect semen quality in many mammals, including stallions. Determinations of semen pH and creatinine and urea concentrations have been used to diagnose urine contamination in raw stallion semen. Unfortunately, practitioners suspecting urine contamination in cooled-shipped samples have no proven means to confirm the presence of urine. Therefore, the objectives of this study were (1) to assess the effects of urine contamination on sperm motility of extended fresh and cooled-stored stallion semen, (2) to evaluate the usefulness of semen color, odor, pH, and creatinine and urea concentrations for urospermia diagnosis, and (3) to evaluate the accuracy of a commercial blood urea nitrogen test strip in diagnosing urine contamination in extended-cooled stallion semen. Thirty-seven ejaculates were obtained from 11 stallions with no history of urospermia before division into 5 mL aliquots, and contamination with stallion urine. Each resulting sample was assessed for sperm motility, color, odor, pH, creatinine, and urea nitrogen concentration using both a semiquantitative test strip (Azostix), and a quantitative automated analyzer before and after cooling for 24 hour. Sperm motility parameters, pH, and creatinine and urea concentrations were analyzed using mixed models. Urine contamination decreased total and progressive motility in all samples before and after cooling (P < 0.05). Mean control total motility was 80% at 0 hour and 67% at 24 hours, whereas urine-contaminated samples ranged from 30% to 71% at 0 hour and 27% to 61% at 24 hours. Control mean urea (29 mg/dL) and creatinine (0.6 mg/dL) concentrations were significantly different (P < 0.05) from all urine-contaminated samples (158 mg/dL and 11.6 mg/dL, respectively) at 0 hour. Similarly, control mean urea (8 mg/dL) and creatinine (0.9 mg/dL) concentrations were significantly different than all urine-contaminated samples at 24 hours. Odor assessment presented moderate sensitivity (65%) and high specificity (100%), while color assessment presented low sensitivity (47%) and moderate specificity (79%) for urine in extended semen. Azostix strips were highly sensitive (95%) and specific (97%). Assessment of color, odor, and pH are not reliable methods to diagnose urine in experimentally contaminated cooled-stored stallion semen. Sperm motility parameters (in raw and cooled semen) are significantly reduced by the presence of urine in a concentration dependent. The results of the present study indicated that determination of urea and creatinine concentrations can be used to diagnose urospermia and that Azostix can be used as a point care method for diagnosing urine contamination in extended cooled stallion semen.
已知在包括种马在内的许多哺乳动物中，精液中混有尿液会影响精液质量。精液pH值以及肌酐和尿素浓度的测定已被用于诊断种马原精液中的尿液污染情况。遗憾的是，怀疑冷藏运输样本存在尿液污染的从业者尚无经证实的方法来确认尿液的存在。因此，本研究的目的是：（1）评估尿液污染对稀释后的新鲜和冷藏保存的种马精液精子活力的影响；（2）评估精液颜色、气味、pH值以及肌酐和尿素浓度在诊断精液中混有尿液方面的实用性；（3）评估一种商用血尿素氮测试条在诊断冷藏保存的种马精液尿液污染方面的准确性。从11匹无精液中混有尿液病史的种马采集了37份射精样本，每份样本分成5毫升的等分试样，并用种马尿液进行污染处理。对每份处理后的样本在冷却24小时前后，使用半定量测试条（Azostix）和定量自动分析仪评估精子活力、颜色、气味、pH值、肌酐和尿素氮浓度。使用混合模型分析精子活力参数、pH值以及肌酐和尿素浓度。尿液污染使所有样本在冷却前后的总活力和前向运动活力均降低（P < 0.05）。对照样本在0小时时的平均总活力为80%，24小时时为67%，而尿液污染样本在0小时时的活力范围为30%至71%，24小时时为27%至61%。对照样本在0小时时的平均尿素浓度（29毫克/分升）和肌酐浓度（0.6毫克/分升）与所有尿液污染样本（分别为158毫克/分升和11.6毫克/分升）有显著差异（P < 0.05）。同样，对照样本在24小时时的平均尿素浓度（8毫克/分升）和肌酐浓度（0.9毫克/分升）与所有尿液污染样本也有显著差异。气味评估的敏感性为中等（65%），特异性高（100%），而颜色评估对稀释精液中尿液的敏感性低（47%），特异性中等（79%）。Azostix测试条的敏感性高（95%），特异性高（97%）。对于实验性污染的冷藏保存种马精液，评估颜色、气味和pH值并非可靠的尿液诊断方法。尿液的存在会使精子活力参数（原精液和冷藏精液中）以浓度依赖的方式显著降低。本研究结果表明，测定尿素和肌酐浓度可用于诊断精液中混有尿液，并且Azostix可作为一种即时检测方法用于诊断冷藏保存的种马精液尿液污染情况。
