Department of Dairy Science, University of Wisconsin, Madison, Wisconsin 53706, USA.
J Dairy Sci. 2013 Aug;96(8):5146-50. doi: 10.3168/jds.2013-6718. Epub 2013 Jun 5.
The monoamine serotonin (5-hydroxytryptamine; 5-HT) has been described as a homeostatic regulator of lactation. Recently, our laboratory determined that 5-HT is involved in the regulation of calcium and glucose homeostasis during the transition period in rodents. More specifically, we demonstrate that 5-HT is responsible for calcium mobilization from bone and upregulation of hepatic gluconeogenic enzymes and mammary gland glucose transporters. Our objective was to investigate the correlation between circulating 5-HT concentrations and circulating ionized calcium, parathyroid hormone-related protein (PTHrP), and glucose concentrations on d 1 postpartum. We also investigated the correlation between circulating 5-HT and milk fever and ketosis incidence and severity in multiparous Holstein cows at the onset of lactation. Blood samples were collected from 42 multiparous cows on d 1 of lactation and analyzed for 5-HT, calcium, glucose, and PTHrP. Milk fever (determined subjectively for each cow on d 1 postpartum) and ketosis incidence and severity (scale 1 to 4, determined objectively for each cow during the first 10 d postpartum) were recorded for all animals. Serum 5-HT was positively correlated with serum calcium and with plasma PTHrP (r>0.37). Serum 5-HT was negatively correlated with milk fever incidence and with ketosis severity (most severe ketosis incidence recorded during the first 10 d postpartum; r<-0.33). Serum calcium and plasma glucose concentrations were negatively correlated with milk fever and ketosis severity, respectively (r<-0.39). These data indicate that 5-HT potentially plays a role in the regulation of calcium and glucose homeostasis during the transition period in cattle, which we previously demonstrated in rodents. Increased circulating concentrations of 5-HT might decrease milk fever at the onset of lactation and ketosis severity during the first 10 d postpartum in dairy cows. Understanding this physiological axis could help describe the underlying mechanisms associated with these periparturient metabolic disorders in dairy cows.
单胺类神经递质 5-羟色胺（5-HT）被描述为哺乳的内稳态调节剂。最近，我们实验室确定 5-HT 参与了啮齿动物过渡期钙和葡萄糖内稳态的调节。更具体地说，我们证明 5-HT 负责从骨骼中动员钙，并上调肝糖异生酶和乳腺葡萄糖转运体。我们的目的是研究产后第 1 天循环 5-HT 浓度与循环离子钙、甲状旁腺激素相关蛋白（PTHrP）和葡萄糖浓度之间的相关性。我们还研究了循环 5-HT 与产奶牛泌乳和酮病发病和严重程度之间的相关性。在泌乳开始时，从 42 头经产荷斯坦奶牛采集血液样本，用于分析 5-HT、钙、葡萄糖和 PTHrP。产后第 1 天对每头奶牛进行主观评估以确定乳热（奶牛热应激），并对所有动物进行客观评估以确定酮病发病和严重程度（1-4 级）。血清 5-HT 与血清钙和血浆 PTHrP 呈正相关（r>0.37）。血清 5-HT 与乳热发病率和酮病严重程度呈负相关（产后前 10 天记录到最严重的酮病发病率；r<-0.33）。血清钙和血浆葡萄糖浓度与乳热和酮病严重程度呈负相关，分别为（r<-0.39）。这些数据表明，5-HT 可能在我们之前在啮齿动物中证明的牛过渡期钙和葡萄糖内稳态调节中发挥作用。在奶牛泌乳开始时，循环 5-HT 浓度增加可能会降低乳热的发病率，并降低产后前 10 天酮病的严重程度。了解这个生理轴可以帮助描述与奶牛这些围产期代谢紊乱相关的潜在机制。
