Gordon Mary E, McKeever Kenneth H, Betros Cynthia L, Manso Filho Helio C
Rutgers, The State University of New Jersey, Equine Science Center, Department of Animal Sciences, 84 Lipman Drive, New Brunswick, NJ 08901, USA.
Vet J. 2007 Jan;173(1):91-100. doi: 10.1016/j.tvjl.2005.11.004. Epub 2005 Dec 27.
Concentrations of hormones related to energy homeostasis may differ between populations with varied body compositions, acting as signals to increase or decrease energy intake and/or expenditure. How these parameters correlate with body composition in horses and how they vary in fit (F) versus unfit (UF) Standardbred racehorses is unclear. The purpose of this study was to test the hypothesis that plasma concentrations of glucose (GLU), insulin (INS), cortisol (CORT), ghrelin (GHRL), adiponectin (ADIP) and leptin (LEP) would be correlated with body composition and differ in fit (F) versus unfit (UF) horses. Fasting plasma samples were taken from 12 unfit (11 +/- 2 years, 521 +/- 77 kg; mean +/- SD) and 34 fit (4 +/- 2 years, 475 +/- 83 kg) Standardbred horses. GHRL, LEP, ADIP, INS and CORT concentrations were measured using radioimmunoassay. GLU concentration was measured using colorometric kits. Body composition data included body weight, body condition score (BCS), and percent fat (%fat) calculated using rump fat thickness measured ultrasonically and the Westervelt equation. Data were analyzed using Pearson Product moment and Student's t tests. There were no differences (P>0.05) between F and UF horses for the plasma concentrations of CORT (69 +/- 14 versus 76 +/- 23 microg/dL), INS (7.2 +/- 3.5 versus 7.1 +/- 1.8 microIU/mL) or GLU (90 +/- 6 versus 86 +/- 7 mg/dL). Plasma GHRL and ADIP concentrations were greater (P<0.05) in F versus UF horses (54 +/- 27 versus 33 +/- 17 pg/mL and 1820 +/- 276 versus 1333 +/- 249 ng/mL, respectively), while plasma LEP was lower in F versus UF (1.0 +/- 0.6 versus 4.4 +/- 2.4 ng/mL, P<0.001). BCS and %fat were lower in F versus UF horses (4.8 +/- 0.3 versus 6.7 +/- 0.5 and 11.9 +/- 1.6 versus 15.4 +/- 2.5%, respectively), with no correlation between %fat and GHRL (-0.12, P>0.05), although there was a positive correlation between %fat and LEP (+0.72, P<0.05), and a negative correlation between %fat and ADIP (-0.40, P<0.05). The data show that in comparing fit and unfit horses, there are variations in body composition as well as concurrent and substantial differences in the concentrations of hormones, cytokines, and other parameters related to the control of appetite and feed intake.
与能量平衡相关的激素浓度在身体组成不同的群体中可能存在差异，这些激素作为信号来增加或减少能量摄入和/或消耗。目前尚不清楚这些参数在马匹中如何与身体组成相关，以及它们在健康（F）与非健康（UF）的标准赛马中如何变化。本研究的目的是检验以下假设：血浆葡萄糖（GLU）、胰岛素（INS）、皮质醇（CORT）、胃饥饿素（GHRL）、脂联素（ADIP）和瘦素（LEP）的浓度将与身体组成相关，并且在健康（F）与非健康（UF）马匹中存在差异。从12匹非健康（11±2岁，521±77千克；平均值±标准差）和34匹健康（4±2岁，475±83千克）的标准赛马中采集空腹血浆样本。使用放射免疫分析法测量GHRL、LEP、ADIP、INS和CORT的浓度。使用比色试剂盒测量GLU浓度。身体组成数据包括体重、身体状况评分（BCS）以及使用超声测量的臀部脂肪厚度和韦斯特维尔特方程计算的脂肪百分比（%fat）。使用皮尔逊积矩相关分析和学生t检验对数据进行分析。F组和UF组马匹的血浆CORT浓度（69±14对76±23微克/分升）、INS浓度（7.2±3.5对7.1±1.8微国际单位/毫升）或GLU浓度（90±6对86±7毫克/分升）没有差异（P>0.05）。F组马匹的血浆GHRL和ADIP浓度高于UF组（分别为54±27对33±17皮克/毫升和1820±276对1333±249纳克/毫升，P<0.05），而F组马匹的血浆LEP低于UF组（1.0±0.6对4.4±2.4纳克/毫升，P<0.001）。F组马匹的BCS和%fat低于UF组（分别为4.8±0.3对6.7±0.5和11.9±1.6对15.4±2.5%），%fat与GHRL之间没有相关性（-0.12，P>0.05），尽管%fat与LEP之间存在正相关（+0.72，P<0.05），与ADIP之间存在负相关（-0.40，P<0.05）。数据表明，在比较健康和非健康马匹时，身体组成存在差异，同时与食欲和采食量控制相关的激素、细胞因子和其他参数的浓度也存在显著差异。
