Integrated Physiology Research, Department of Obesity and NASH Pharmacology, Global Drug Discovery, Novo Nordisk A/S, Måløv, Denmark.
Integrated Physiology Research, Department of Diabetes Pharmacology, Global Drug Discovery, Novo Nordisk A/S, Måløv, Denmark.
Mol Metab. 2023 Mar;69:101689. doi: 10.1016/j.molmet.2023.101689. Epub 2023 Feb 4.
A fundamental difference between physiological and pharmacological studies in rats and humans is that withdrawal of blood from conscious rats necessitates restraint which inevitably inflicts a higher level of stress. We investigated the impact of handling on acute glucose regulation and secretion of glucoregulatory hormones in rats.
Fasted male Sprague Dawley rats (375-400 g, n = 11) were given an oral glucose tolerance test (OGTT) by gavage (2 g/kg). Blood was sampled frequently until 90 min after challenge by handheld sampling (HS) or by automated sampling (AS). In the HS experiment, blood was withdrawn by restraint and sublingual vein puncture; two weeks later, samples were obtained by AS through an implanted catheter in a carotid artery, allowing sampling without disturbing the animals.
On the day of HS, post challenge glucose AUCs were ∼17% higher (P < 0.0001), despite gastric emptying (AUC) being reduced by ∼30% (P < 0.0001). Plasma insulin AUC was 3.5-fold lower (P < 0.001), and glucose-dependent insulinotropic peptide (GIP) AUC was reduced by ∼36% but glucagon-like peptide-1 concentrations were not affected. Glucagon concentrations were higher both before and after challenge (fold difference in AUCs = 3.3). Adrenocorticotropin (ACTH) and corticosterone AUCs were 2.4-fold and 3.6-fold higher (P < 0.001), respectively.
Our study highlights that sampling of blood from conscious rats by sublingual vein puncture inflicts stress which reduces glucose absorption and glucose tolerance and blunts secretion of insulin and GIP. As blood sampling in humans are less stressful, standard procedures of conducting OGTT's in rats by HS presumably introduce an interspecies difference that may have negative consequences for translatability of test results.
在大鼠和人类的生理学和药理学研究之间存在一个基本差异，即从清醒大鼠中抽血需要束缚，这不可避免地会造成更高水平的应激。我们研究了处理对大鼠急性血糖调节和糖调节激素分泌的影响。
禁食雄性 Sprague Dawley 大鼠（375-400g，n=11）经胃管给予口服葡萄糖耐量试验（OGTT）（2g/kg）。通过手动采样（HS）或自动采样（AS）频繁采血，直至挑战后 90 分钟。在 HS 实验中，通过束缚和舌下静脉穿刺抽血；两周后，通过植入颈动脉内的导管进行 AS 采样，允许在不干扰动物的情况下采样。
在 HS 日，尽管胃排空（AUC）减少了约 30%（P<0.0001），但挑战后葡萄糖 AUC 增加了约 17%（P<0.0001）。血浆胰岛素 AUC 降低了 3.5 倍（P<0.001），葡萄糖依赖性胰岛素释放肽（GIP） AUC 降低了约 36%，但胰高血糖素样肽-1 浓度不受影响。在挑战前后，胰高血糖素浓度均升高（AUC 倍数差异为 3.3）。促肾上腺皮质激素（ACTH）和皮质酮 AUC 分别升高了 2.4 倍和 3.6 倍（P<0.001）。
我们的研究强调，通过舌下静脉穿刺从清醒大鼠中采血会造成应激，从而降低葡萄糖吸收和葡萄糖耐量，并削弱胰岛素和 GIP 的分泌。由于人类采血的应激较小，因此通过 HS 进行大鼠 OGTT 的标准程序可能会引入种间差异，这可能对测试结果的可转化性产生负面影响。
