De Koster J, Urh C, Hostens M, Van den Broeck W, Sauerwein H, Opsomer G
Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
Institute for Animal Science, Physiology and Hygiene Unit, University of Bonn, 53115 Bonn, Germany.
Domest Anim Endocrinol. 2017 Apr;59:100-104. doi: 10.1016/j.domaniend.2016.12.004. Epub 2016 Dec 18.
The aim of the present study was to describe the relationship between serum adiponectin concentration and peripheral tissue insulin response in dairy cows with a variable body condition score (BCS) during the dry period. Cows were selected at the beginning of the dry period based on BCS (BCS <3.75, n = 4; BCS >3.75, n = 5). Animals were followed from the beginning of the dry period by weekly blood sampling and assessment of BCS and backfat thickness. Weekly blood samples were analyzed for adiponectin concentration using a bovine specific ELISA. Hyperinsulinemic euglycemic clamp tests were performed at the end of the dry period to measure peripheral tissue insulin response. Insulin dose response curves were established for both glucose and fatty acid metabolism. Regression analysis revealed that the serum concentrations of adiponectin dropped at the end of the dry period (P < 0.05) and were negatively associated with BCS (P < 0.05). At the level of the glucose metabolism, serum concentrations of adiponectin were positively correlated with insulin responsiveness (reflecting the maximal effect of insulin; r = 0.76, P < 0.05), but not with insulin sensitivity (reflecting the insulin concentration needed to achieve halfmaximal effect; r = -0.54, P = 0.13). At the level of the fatty acid metabolism, greater adiponectin concentrations were negatively correlated with lower NEFA levels during the HEC test reflecting the insulin responsiveness of the NEFA metabolism (r = -0.61, P = 0.08), whereas there was no association with the insulin sensitivity of the NEFA metabolism (r = -0.16, P = 0.67). In conclusion, serum concentrations of adiponectin were negatively associated with the BCS of dairy cows during the dry period and positively associated with insulin responsiveness of the glucose and fatty acid metabolism.
本研究的目的是描述干奶期体况评分（BCS）不同的奶牛血清脂联素浓度与外周组织胰岛素反应之间的关系。在干奶期开始时，根据BCS挑选奶牛（BCS<3.75，n = 4；BCS>3.75，n = 5）。从干奶期开始对动物进行每周一次的采血，并评估BCS和背膘厚度。使用牛特异性酶联免疫吸附测定法分析每周采集的血样中的脂联素浓度。在干奶期末进行高胰岛素-正葡萄糖钳夹试验，以测量外周组织胰岛素反应。建立了葡萄糖和脂肪酸代谢的胰岛素剂量反应曲线。回归分析显示，干奶期末血清脂联素浓度下降（P<0.05），且与BCS呈负相关（P<0.05）。在葡萄糖代谢水平上，血清脂联素浓度与胰岛素反应性呈正相关（反映胰岛素的最大作用；r = 0.76，P<0.05），但与胰岛素敏感性无关（反映达到最大作用一半所需的胰岛素浓度；r = -0.54，P = 0.13）。在脂肪酸代谢水平上，在高胰岛素-正葡萄糖钳夹试验期间，较高的脂联素浓度与较低的非酯化脂肪酸（NEFA）水平呈负相关，反映了NEFA代谢的胰岛素反应性（r = -0.61，P = 0.08），而与NEFA代谢的胰岛素敏感性无关（r = -0.16，P = 0.67）。总之，干奶期奶牛血清脂联素浓度与BCS呈负相关，与葡萄糖和脂肪酸代谢的胰岛素反应性呈正相关。
