De Matteis L, Bertoni G, Lombardelli R, Wellnitz O, Van Dorland H A, Vernay M C M B, Bruckmaier R M, Trevisi E
Istituto di Zootecnica, Facoltà di Scienze Agrarie, Alimentari ed Ambientali, Università Cattolica del Sacro Cuore, Piacenza, Italy.
Veterinary Physiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
J Anim Physiol Anim Nutr (Berl). 2017 Jun;101(3):511-520. doi: 10.1111/jpn.12463. Epub 2016 Apr 14.
The link between energy availability, turnover of energy substrates and the onset of inflammation in dairy cows is complex and poorly investigated. To clarify this, plasma inflammatory variables were measured in mid-lactating dairy cows allocated to three groups: hyperinsulinemic hypoglycaemic clamp, induced by insulin infusion (HypoG, n = 5); hyperinsulinemic euglycaemic clamp, induced by insulin and glucose infusion (EuG; n = 6); control, receiving a saline solution infusion (NaCl; n = 6). At 48 h after the start of i.v. infusions, two udder quarters per cow were challenged with 200 μg of E. coli lipopolysaccharide (LPS). Individual blood samples were taken before clamps, before LPS challenge (i.e. 48 h after clamps) and 6.5 h after. At 48 h, positive acute phase proteins (posAPP) did not differ among groups, whereas albumin and cholesterol (index of lipoproteins), negative APP (negAPP), were lower (p < 0.05) in EuG compared to NaCl and HypoG. The concentration of IL-6 was greater in EuG (p < 0.05) but only vs. HypoG. At 6.5 h following LPS challenge, IL-6 increased in the NaCl and EuG clamps (p < 0.05), while TNF-α increased (p < 0.05) in the EuG only. Among the posAPP, haptoglobin markedly increased in EuG (p < 0.05), but not in NaCl (p = 0.76) and in HypoG; ceruloplasmin tended to decline during LPS challenge, the reduction was significant when all animals were considered (p < 0.05). Conversely, all the negAPP showed a marked reduction 6.5 h after LPS challenge in the three groups. In conclusion, EuG caused an inflammatory status after 48-h infusion (i.e. decrease of negAPP) and induced a quicker acute phase response (e.g. marked rise of TNF-α, IL-6) after the intramammary LPS challenge. These data suggest that the simultaneous high availability of glucose and insulin at the tissue-level makes dairy cows more susceptible to inflammatory events. In contrast, HypoG seems to attenuate the inflammatory response.
能量供应、能量底物周转与奶牛炎症发生之间的联系复杂且研究较少。为阐明这一点，对处于泌乳中期的奶牛进行分组并测量其血浆炎症变量，分组如下：通过输注胰岛素诱导产生高胰岛素低血糖钳夹组（HypoG，n = 5）；通过输注胰岛素和葡萄糖诱导产生高胰岛素正常血糖钳夹组（EuG；n = 6）；对照组，输注生理盐水（NaCl；n = 6）。在静脉输注开始48小时后，每头奶牛的两个乳腺象限用200μg大肠杆菌脂多糖（LPS）进行刺激。在钳夹前、LPS刺激前（即钳夹后48小时）以及刺激后6.5小时采集个体血样。在48小时时，各组之间的阳性急性期蛋白（posAPP）无差异，而与NaCl组和HypoG组相比，EuG组的白蛋白和胆固醇（脂蛋白指标）、阴性急性期蛋白（negAPP）较低（p < 0.05）。EuG组的IL - 6浓度更高（p < 0.05），但仅与HypoG组相比。在LPS刺激后6.5小时，NaCl组和EuG组钳夹中的IL - 6升高（p < 0.05），而仅EuG组的TNF - α升高（p < 0.05）。在posAPP中，触珠蛋白在EuG组显著升高（p < 0.05），但在NaCl组（p = 0.76）和HypoG组中未升高；在LPS刺激期间，铜蓝蛋白有下降趋势，当考虑所有动物时，这种下降具有显著性（p < 0.05）。相反，在LPS刺激后6.5小时，三组中的所有negAPP均显著降低。总之，EuG组在48小时输注后导致炎症状态（即negAPP降低），并在乳房内LPS刺激后诱导更快的急性期反应（如TNF - α、IL - 6显著升高）。这些数据表明，组织水平上葡萄糖和胰岛素同时高可用性使奶牛更容易发生炎症事件。相比之下，HypoG组似乎减弱了炎症反应。
