The objectives of this study were to describe pharmacokinetic and pharmacodynamic changes as a result of a single intravenous administration of magnesium sulfate (MgSO₄) to healthy horses. MgSO₄ is a magnesium salt that has been used to calm horses in equestrian competition and is difficult to regulate because magnesium is an essential constituent of all mammals. Six healthy adult female horses were administered a single intravenous dose of MgSO₄ at 60 mg/kg of body weight over 5 min. Blood, urine, and cerebrospinal fluid (CSF) samples were collected, and cardiovascular parameters were monitored and echocardiograms performed at predetermined times. Noncompartmental pharmacokinetic analysis was applied to plasma concentrations of ionized magnesium (Mg²⁺). Objective data were analyzed using the Wilcoxon rank‐sum test with p < .05 used as a determination for significance. Plasma concentrations of Mg²⁺ increased nearly fivefold, ionized calcium (Ca²⁺) decreased by nearly 10%, and the Ca²⁺ to Mg²⁺ ratio declined more than 3.5‐fold and remained different than baseline until 24 hr (p < .05). Significant changes were seen with urinary fractional excretion of electrolytes, cardiovascular parameters, and echocardiographic measurements. No changes were detected in CSF electrolyte concentrations. The decrease in Ca²⁺ result of hypermagnesemia supports the interaction between these cations. Alterations detected in plasma electrolyte concentrations and urinary fractional excretion of electrolytes may serve as biomarkers for regulatory control for the nefarious administration of MgSO₄.

中文翻译：

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实验诱导的高镁血症后镁的药代动力学及其对临床变量的影响。

这项研究的目的是描述向健康马单次静脉注射硫酸镁（MgSO ₄）后的药代动力学和药效学变化。MgSO ₄是一种镁盐，已被用于使马术比赛中的马匹平静下来，并且由于镁是所有哺乳动物的必不可少的成分，因此难以调节。六只健康的成年雌马在5分钟内以60 mg / kg体重的剂量静脉内注射MgSO ₄。收集血液，尿液和脑脊液（CSF）样品，监测心血管参数并在预定时间进行超声心动图检查。将非房室药代动力学分析应用于电离镁（Mg²⁺）。使用Wilcoxon秩和检验分析客观数据，p  <.05用作显着性测定。血浆中Mg ^2+的浓度增加了近五倍，离子钙（Ca ²⁺）减少了近10％，Ca ²⁺与Mg ^2+的比率下降了3.5倍以上，并且与基线之间一直保持差异，直到24小时（p  < .05）。电解质的尿分数排泄，心血管参数和超声心动图测量显示出明显的变化。CSF电解质浓度未检测到变化。Ca ²⁺的减少高镁血症的结果支持了这些阳离子之间的相互作用。在血浆电解质浓度和尿液尿分数排泄物中检测到的变化可作为生物标志物，用于恶性施用MgSO _4的调节控制。