Harvey John W, Pate Melanie G, Kivipelto Jan, Asquith Richard L
Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
Vet Clin Pathol. 2005 Sep;34(3):248-54. doi: 10.1111/j.1939-165x.2005.tb00049.x.
Pregnancy and lactation result in increased metabolic demands. Although homeostatic mechanisms function to keep substances in blood at relatively constant levels, some changes in the concentrations of routine clinical chemistry analytes are likely to occur.
The purpose of this study was to determine what physiological changes occur in serum clinical biochemistry analytes in pregnant and nursing mares, and to determine whether the changes were substantial enough to warrant separate reference intervals for pregnant or lactating horses.
Forty-two Quarter Horse, Thoroughbred, Saddlebred, Standardbred and Morgan mares were entered into the study while pregnant. They were bled once each month through birth. Studies were continued on 20 mares until their foals were weaned. Test results were tabulated by time before or after birth. Serum biochemistry values were determined by standard methods using automated analyzers. Test results were analyzed using the Kruskal-Wallis 1-way ANOVA on ranks. If a significant difference was found (P<.05), Dunn's multiple comparison procedure was performed on all pairs. Results from pregnant and nursing mares also were compared with a reference group of 19 open, nonlactating mares.
Serum triglyceride, potassium, creatinine, and total bilirubin concentrations were lower during lactation than during pregnancy. Serum calcium concentration also was slightly decreased at 2 time points during lactation. Triglyceride concentration was highest during midgestation, while bilirubin and creatinine values increased, and potassium and calcium remained constant during pregnancy. Serum urea concentration also remained constant during pregnancy but increased during lactation. Serum phosphate concentration was lowest during midgestation and highest during lactation. Total CO2 values were highest, and anion gaps were lowest, during midgestation. No significant differences were found in serum albumin, globulin, albumin:globulin ratio, total protein, or glucose values. When compared with the reference group of open mares, serum triglyceride, potassium, bilirubin, and total CO2 concentrations were lower, and anion gap was higher in horses that were nursing.
Although most biochemical values remained relatively constant, significant differences were observed during pregnancy and lactation. Changes in the concentrations of triglycerides, potassium, bilirubin, total CO2, and anion gap during lactation were substantial enough to warrant separate reference intervals for lactating horses.
怀孕和哺乳会导致代谢需求增加。尽管体内平衡机制发挥作用使血液中的物质保持相对恒定的水平，但常规临床化学分析物的浓度仍可能发生一些变化。
本研究的目的是确定怀孕和哺乳母马血清临床生化分析物会发生哪些生理变化，并确定这些变化是否足够显著，需要为怀孕或哺乳母马制定单独的参考区间。
42匹夸特马、纯种马、鞍马、标准马和摩根马在怀孕时进入本研究。在分娩前每月采血一次。对20匹母马持续进行研究，直至其幼驹断奶。测试结果按出生前后时间列表。血清生化值采用标准方法通过自动分析仪测定。使用Kruskal-Wallis秩和单向方差分析对测试结果进行分析。如果发现显著差异（P<0.05），则对所有配对进行邓恩多重比较程序。还将怀孕和哺乳母马的结果与19匹未怀孕、未哺乳母马的参考组进行比较。
哺乳期血清甘油三酯、钾、肌酐和总胆红素浓度低于孕期。哺乳期血清钙浓度在两个时间点也略有下降。甘油三酯浓度在妊娠中期最高，而胆红素和肌酐值升高，钾和钙在孕期保持恒定。血清尿素浓度在孕期也保持恒定，但在哺乳期升高。血清磷酸盐浓度在妊娠中期最低，在哺乳期最高。总二氧化碳值在妊娠中期最高，阴离子间隙在妊娠中期最低。血清白蛋白、球蛋白、白蛋白：球蛋白比值、总蛋白或葡萄糖值未发现显著差异。与未怀孕母马的参考组相比，哺乳母马的血清甘油三酯、钾、胆红素和总二氧化碳浓度较低，阴离子间隙较高。
尽管大多数生化值保持相对恒定，但在怀孕和哺乳期观察到显著差异。哺乳期甘油三酯、钾、胆红素、总二氧化碳和阴离子间隙浓度的变化足够显著，需要为哺乳母马制定单独的参考区间。
