Geor R J, Stewart-Hunt L, McCutcheon L J
Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Ontario, Canada.
Equine Vet J Suppl. 2010 Nov(38):129-34. doi: 10.1111/j.2042-3306.2010.00218.x.
There is limited information about factors regulating glucose utilisation post exercise in horses.
To determine the effects of a single bout of moderate intensity exercise on measures of insulin-mediated (IMGU) and noninsulin-mediated (NIMGU) glucose uptake during a hyperglycaemic clamp (HC).
Hyperglycaemic clamps were administered in random order to 8 Standardbreds under 4 conditions: 1) rest, insulinopenia (R-L); 2) rest, hyperinsulinaemia (R-H); 3) post exercise (45 min at ∼ 50% VO2peak), insulinopenia (Ex-L) and 4) post exercise, hyperinsulinaemia (Ex-H). In the R-L and Ex-L trials, somatostatin was infused to suppress insulin secretion and induce insulinopenia. After 30 min, a 2 h HC was initiated with plasma glucose concentrations maintained at ∼ 10 mmol/l by variable glucose infusion. In R-H and Ex-H, regular insulin (1.0 mu/kg bwt/min) was also administered to induce physiological hyperinsulinaemia. Serum insulin and C-peptide concentrations were measured in samples obtained at 10 min intervals. Glucose uptake was calculated from mean glucose infusion rate (GIR) during the last 60 min of the HC.
In all HCs C-peptide remained below baseline concentrations, evidence of suppression of insulin secretion by somatostatin. Overall, mean ± s.e. insulin concentrations during the final 60 min of the HC in R-L and Ex-L were 5.7 ± 1.1 and 6.9 ± 1.9 mu/l respectively, and corresponding values in R-H and Ex-H were 64.1 ± 11.1 and 61.2 ± 10.9 mu/l. Prior exercise affected IMGU but not NIMGU. Over the final 60 min of the HC, mean GIR was higher (P < 0.001) in Ex-H (5.6 ± 1.1 mg/kg bwt/min) than in R-H (3.3 ± 0.9 mg/kg bwt/min), whereas mean GIR did not differ (P = 0.26) between R-L (1.2 ± 0.3 mg/kg bwt/min) and Ex-L (1.8 ± 0.5 mg/kg bwt/min).
A single bout of moderate intensity exercise increased glucose uptake during a hyperglycaemic clamp under hyperinsulinaemic conditions but not under somatostatin-induced insulinopenia.
关于调节马匹运动后葡萄糖利用的因素，相关信息有限。
确定单次中等强度运动对高血糖钳夹（HC）期间胰岛素介导的葡萄糖摄取（IMGU）和非胰岛素介导的葡萄糖摄取（NIMGU）指标的影响。
对8匹标准赛马按照随机顺序在4种条件下进行高血糖钳夹：1）休息，胰岛素缺乏（R-L）；2）休息，高胰岛素血症（R-H）；3）运动后（约50%VO₂峰值下运动45分钟），胰岛素缺乏（Ex-L）；4）运动后，高胰岛素血症（Ex-H）。在R-L和Ex-L试验中，输注生长抑素以抑制胰岛素分泌并诱导胰岛素缺乏。30分钟后，开始2小时的高血糖钳夹，通过可变葡萄糖输注将血浆葡萄糖浓度维持在约10 mmol/l。在R-H和Ex-H中，还给予常规胰岛素（1.0 mu/kg体重/分钟）以诱导生理性高胰岛素血症。每隔10分钟采集的样本中测量血清胰岛素和C肽浓度。根据高血糖钳夹最后60分钟的平均葡萄糖输注率（GIR）计算葡萄糖摄取量。
在所有高血糖钳夹中，C肽浓度均低于基线水平，这是生长抑素抑制胰岛素分泌的证据。总体而言，高血糖钳夹最后60分钟期间，R-L和Ex-L的平均±标准误胰岛素浓度分别为5.7±1.1和6.9±1.9 mu/l，R-H和Ex-H的相应值分别为64.1±11.1和61.2±10.9 mu/l。先前的运动影响胰岛素介导的葡萄糖摄取，但不影响非胰岛素介导的葡萄糖摄取。在高血糖钳夹的最后60分钟内，Ex-H（5.6±1.1 mg/kg体重/分钟）的平均GIR高于R-H（3.3±0.9 mg/kg体重/分钟）（P<0.001），而R-L（1.2±0.3 mg/kg体重/分钟）和Ex-L（1.8±0.5 mg/kg体重/分钟）之间的平均GIR无差异（P = 0.26）。
单次中等强度运动在高胰岛素血症条件下的高血糖钳夹期间增加了葡萄糖摄取，但在生长抑素诱导的胰岛素缺乏情况下未增加。
