School of Animal Sciences, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Baton Rouge 70803-4210, USA.
J Anim Sci. 2010 Mar;88(3):926-36. doi: 10.2527/jas.2009-2337. Epub 2009 Dec 4.
Mares and geldings in good body condition selected for hyperleptinemia vs. normal leptin concentrations were studied to determine whether the hyperleptinemic condition affected various characteristics of the hematologic and hormonal systems after a challenge with lipopolysaccharide endotoxin. Four mares and 4 geldings that were determined to be hyperleptinemic (mean plasma leptin concentrations of 10.0 to 15.5 ng/mL) and 4 mares and 4 geldings with mean plasma leptin concentrations between 2.4 and 5.5 ng/mL were administered Escherichia coli O55:B5 endotoxin (35 ng/kg of BW in 500 mL of saline over a 30-min infusion), or saline only, in pairs in a single-switchback design, with horses and treatments randomly assigned for the first infusion. Physiological variables and blood components were monitored for 24 h after the onset of infusions. Treatments were switched and the second infusions were administered 8 d later. Relative to vehicle infusion, endotoxin infusion increased (P < 0.01) the rectal temperature, heart rate, respiration rate, plasma total protein concentration, and blood packed cell volume; there was an interaction of leptin status, endotoxin treatment, and time for heart rate (P = 0.039), respiration rate (P = 0.018), and plasma total protein concentration (P = 0.054). Blood concentrations of leukocytes, lymphocytes, and neutrophils all decreased (P < 0.001) after endotoxin infusion; there was an interaction (P = 0.0057) between sex and leptin status for blood platelet concentration. Plasma leptin concentrations increased (P = 0.013) after endotoxin infusion in both hyperleptinemic horses and those with reduced leptin concentrations. There were interactions (P < 0.037) of sex with endotoxin treatment and time for plasma concentrations of cortisol and prolactin, whereas plasma GH concentrations were affected (increased; P < 0.001) only by time after infusion. Given that the effects of hyperleptinemia were generally minor, it was concluded that the hyperleptinemic condition, and its associated type-2 diabetic symptoms, has a minimal impact on the components of the hematologic and hormonal systems studied.
选择体况良好的母马和公马进行高瘦素血症与正常瘦素浓度的比较研究，以确定高瘦素血症状态是否会影响脂多糖内毒素（lipopolysaccharide endotoxin）刺激后的血液学和激素系统的各种特征。4 匹被确定为高瘦素血症（平均血浆瘦素浓度为 10.0 至 15.5ng/ml）的母马和 4 匹平均血浆瘦素浓度在 2.4 至 5.5ng/ml 之间的公马，以及 4 匹被确定为高瘦素血症（mean plasma leptin concentrations of 10.0 to 15.5ng/mL）的母马和 4 匹平均血浆瘦素浓度在 2.4 至 5.5ng/ml 之间的公马，接受大肠杆菌 O55:B5 内毒素（35ng/kgBW 在 30 分钟输注的 500ml 盐水中）或仅盐水，在单个折返设计中配对，马匹和治疗随机分配给第一次输注。在输注开始后 24 小时监测生理变量和血液成分。治疗方案切换，第二次输注在 8 天后进行。与载体输注相比，内毒素输注增加（P<0.01）直肠温度、心率、呼吸率、血浆总蛋白浓度和血液红细胞压积；心率（P=0.039）、呼吸率（P=0.018）和血浆总蛋白浓度（P=0.054）存在瘦素状态、内毒素处理和时间的相互作用。白细胞、淋巴细胞和中性粒细胞的血液浓度在接受内毒素输注后均下降（P<0.001）；血小板浓度存在性别与瘦素状态的相互作用（P=0.0057）。内毒素输注后，高瘦素血症马和瘦素浓度降低的马的血浆瘦素浓度均升高（P=0.013）。性别与内毒素处理和时间对皮质醇和催乳素的血浆浓度有相互作用（P<0.037），而生长激素（GH）的血浆浓度仅受输注后时间的影响（增加；P<0.001）。鉴于高瘦素血症的影响通常较小，因此可以得出结论，高瘦素血症状态及其相关的 2 型糖尿病症状对所研究的血液学和激素系统的组成部分影响很小。
