BACKGROUND Biomechanical remodeling of coronary resistance arteries in physiological left ventricular hypertrophy has not yet been analyzed, and the possible sex differences are unknown. METHODS Wistar rats were divided into four groups: male and female sedentary controls (MSe and FSe) and male and female animals undergoing a 12-week intensive swim training program (MEx and FEx). On the last day, the in vitro contractility, endothelium-dependent dilatation, and biomechanical properties of the intramural coronary resistance arteries were investigated by pressure microarteriography. Elastica and collagen remodeling were studied in histological sections. RESULTS A similar outer radius and reduced inner radius resulted in an elevated wall to lumen ratio in the MEx and FEx animals compared to that in the sedentary controls. The wall elastic moduli increased in the MEx and FEx rats. Spontaneous and TxA2 agonist-induced tone was increased in the FEx animals, whereas endothelium-dependent relaxation became more effective in MEx rats. Arteries of FEx rats had stronger contraction, while arteries of MEx animals had improved dilation. CONCLUSIONS According to our results, the coronary arterioles adapted to an elevated load during long-term exercise, and this adaptation depended on sex. It is important to emphasize that in addition to differences, we also found many similarities between the sexes in the adaptive response to exercise. The observed sport adaptation in the coronary resistance arteries of rats may contribute to a better understanding of the physiological and pathological function of these arteries in active and retired athletes of different sexes.

中文翻译：

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长期运动会导致雄性和雌性大鼠冠状动脉阻力小动脉的形态和生物力学变化。

背景技术尚未分析生理性左心室肥大中冠状动脉阻力动脉的生物力学重塑，并且可能的性别差异未知。方法Wistar大鼠分为四组：雄性和雌性久坐对照（MSe和FSe）和雄性和雌性动物，接受12周的强化游泳训练程序（MEx和FEx）。在最后一天，通过压力微动脉造影研究了壁内冠状动脉阻力动脉的体外收缩性，内皮依赖性扩张和生物力学特性。在组织学切片中研究了弹性和胶原重塑。结果与久坐对照组相比，相似的外半径和减小的内半径导致MEx和FEx动物的壁腔比增加。在MEx和FEx大鼠中壁弹性模量增加。在FEx动物中，自发性和TxA2激动剂诱导的语调增加，而在MEx大鼠中内皮依赖性舒张变得更有效。FEx大鼠的动脉具有更强的收缩能力，而MEx动物的动脉具有更好的扩张能力。结论根据我们的研究结果，长期运动过程中冠状小动脉适应了较高的负荷，并且这种适应性取决于性别。重要的是要强调，除了差异之外，我们还发现了在运动适应性反应中性别之间的许多相似之处。在大鼠的冠状动脉阻力动脉中观察到的运动适应性可能有助于更好地了解不同性别的活跃和退休运动员中这些动脉的生理和病理功能。