Department of Human Morphology and Applied Biology, University of Pisa, Italy.
Histol Histopathol. 2012 Jun;27(6):753-69. doi: 10.14670/HH-27.753.
The effects of training are dependent on complex, adaptive changes which are induced by acute physical exercise at different levels. In particular, evidence shows that the hypothalamus-pituitary-adrenocortical axis, as well as the sympatho-adrenomedullary system, is mainly involved in mediating the physiological effects of physical exercise. The aim of the present study was to investigate, through a morphological and biochemical approach, the effects of training on the adrenal gland of mice, following two different protocols consisting of either low- or high-intensity training. Mice were run daily on a motorised treadmill for 8 weeks, at a velocity corresponding to 60% (low-intensity exercise) or 90% (high-intensity exercise) of the maximal running velocity previously determined by an incremental exercise test. We found that physical exercise produced an increase in the adrenal gland size compared with the control (sedentary) mice. The increase was 31.04% for mice that underwent high-intensity exercise and 10.08% for mice that underwent low intensity exercise, and this appeared to be the result of an increase in the area of both the adrenal cortex and adrenal medulla. Morphological analysis of the adrenal cortex showed that both types of exercise produced an increase in cytoplasmic vacuoles in steroidogenic cells, appearing more abundant after high-intensity exercise. No change was found in the reticulate zone. In the adrenal medulla, despite the absence of morphological changes, immunohistochemistry for tyrosine hydroxylase, dopamine β-hydroxylase and phenyl-ethanolamine-N-methyltransferase demonstrated an increased immunopositivity for these cathecolamine-synthesizing enzymes after intense exercise. These results were confirmed by immunoblot accompanied by densitometric analysis.
训练的效果取决于复杂的适应性变化，这些变化是由不同水平的急性体育锻炼引起的。特别是，有证据表明，下丘脑-垂体-肾上腺皮质轴以及交感-肾上腺髓质系统主要参与介导体育锻炼的生理效应。本研究的目的是通过形态和生化方法研究训练对小鼠肾上腺的影响，实验采用两种不同的方案，分别为低强度和高强度训练。小鼠每天在电动跑步机上跑步 8 周，速度对应于之前递增运动测试确定的最大跑步速度的 60%（低强度运动）或 90%（高强度运动）。我们发现，与对照组（安静）小鼠相比，体育锻炼使肾上腺增大。高强度运动组的肾上腺增大了 31.04%，低强度运动组增大了 10.08%，这似乎是肾上腺皮质和髓质面积增加的结果。肾上腺皮质的形态分析表明，两种类型的运动都导致类固醇生成细胞的细胞质空泡增加，高强度运动后更为明显。网状带没有变化。在肾上腺髓质中，尽管没有形态变化，但酪氨酸羟化酶、多巴胺 β-羟化酶和苯乙醇胺-N-甲基转移酶的免疫组化显示，这些儿茶酚胺合成酶在剧烈运动后免疫阳性增加。这些结果通过免疫印迹和密度分析得到了证实。
