Prior R L
J Anim Sci. 1983 Oct;57(4):1029-36. doi: 10.2527/jas1983.5741029x.
Experiments were conducted with 40 steers to evaluate the effects of diet (alfalfa hay vs high concentrate) on the rates of elimination of D- and L-lactate from plasma. Plasma L- and D-lactate clearance rates were determined before (Period I) and 114 d after (Period II) an abrupt switch from the alfalfa hay to the high concentrate diet. One group of steers received the hay diet throughout the experiment. Diet or period did not alter the rate of disappearance of L-lactate from plasma; the half-life was 13.5 to 15.5 min. D-lactate disappearance from plasma followed an exponential decay curve with at least two components; however, diet or period did not alter the calculated rates of disappearance. The half-life of the first component was 9 to 28 min and the second component was 207 min. Characteristics describing D- or L-lactate metabolism were not highly correlated with lactate utilization for fatty acid synthesis. These data demonstrate that, in steers adapted to a high concentrate diet consuming 18.2 Mcal ME X head-1 X d-1, clearance of D(-)- or L(+)-lactate is not different from that in steers fed alfalfa hay consuming 23.1 Mcal ME X head-1 X d-1.
用40头阉牛进行试验，以评估日粮（苜蓿干草与高能量精料）对血浆中D-乳酸和L-乳酸清除率的影响。在从苜蓿干草日粮突然转换至高能量精料日粮之前（第一阶段）和之后114天（第二阶段），测定血浆L-乳酸和D-乳酸清除率。一组阉牛在整个试验过程中采食干草日粮。日粮或阶段对血浆中L-乳酸的消失速率没有影响；半衰期为13.5至15.5分钟。血浆中D-乳酸的消失遵循至少有两个成分的指数衰减曲线；然而，日粮或阶段对计算出的消失速率没有影响。第一个成分的半衰期为9至28分钟，第二个成分为207分钟。描述D-乳酸或L-乳酸代谢的特征与用于脂肪酸合成的乳酸利用率没有高度相关性。这些数据表明，在适应采食18.2兆卡代谢能·头⁻¹·天⁻¹高能量精料日粮的阉牛中，D(-)-乳酸或L(+)-乳酸的清除率与采食23.1兆卡代谢能·头⁻¹·天⁻¹苜蓿干草的阉牛没有差异。
