ABSTRACT

Background: 8-week old Sprague Dawley rats represent the standard rodent model of oesophageal surgery, which is challenging and might be eased by larger oesophageal lengths. Therefore, we aimed to analyse whether oesophageal length would linearly increase with bodyweight and ensure comparable experimental conditions. Methods: We analysed 41 8-week old Sprague Dawley rats of both sexes by linear regression of oesophageal length with sex as an interaction term for bodyweight. Based on exploratory investigations, analyses were powered to 80% for a deviation of the regression’s slope from zero. Results: Linear regression was statistically significant with F(3,37) = 3.29, P=0.0312 with an adjusted R² of 0.15 (95% CI: 0.02–0.43). Oesophageal length could be modelled by 4.56 (95% CI: 1.45–6.69) + 0.007 (95% CI: −0.002–0.019) x bodyweight in grams + 6.7 (95% CI: 1.86–11.1) x sex (1=male) – 0.02 (95% CI: −0.04–(−0.005)) x bodyweight x sex. Exploration of the interaction revealed that oesophageal length increased with bodyweight for female rats, but decreased in males. Conclusions: Sex represents a major interaction for oesophageal length in an age-adjusted cohort of Sprague Dawley rats. This may have relevant implications for reproducibility of rat models of oesophageal surgery, but may be different in inbred strains.

摘要

背景：8周大的Sprague Dawley大鼠代表了食管手术的标准啮齿动物模型，这具有挑战性，并且较大的食管长度可能会缓解这种情况。因此，我们旨在分析食管长度是否会随体重线性增加，并确保可比较的实验条件。方法：我们通过食管长度与性别的线性回归作为体重的相互作用项，分析了41只8周大的Sprague Dawley雌雄大鼠。根据探索性调查，回归斜率与零的偏差为80％。结果：线性回归具有统计学显着性，F（3,37）= 3.29，P = 0.0312，R调整后²为0.15（95％CI：0.02–0.43）。可以用4.56（95％CI：1.45–6.69）+ 0.007（95％CI：-0.002-0.019）x体重克+ 6.7（95％CI：1.86–11.1）x性别（1 =男性）来模拟食道长度– 0.02（95％CI：−0.04 –（− 0.005））x体重x性别。对相互作用的探索表明，雌性大鼠食管长度随体重增加而增加，而雄性大鼠则减少。结论：在Sprague Dawley大鼠的年龄校正队列中，性别代表了食管长度的主要相互作用。这可能对食道手术大鼠模型的可重复性具有重要意义，但在近交系中可能有所不同。