A 12-week intensive swim training program in rats resulted in an elevated wall-to-lumen ratio and increased wall elastic moduli in coronary resistance arteries, with sex-dependent functional adaptations.
Does a 12-week intensive swim training program alter morphological and biomechanical properties of coronary resistance arterioles in male and female Wistar rats?
Long-term exercise induces sex-specific biomechanical and morphological adaptations in coronary resistance arteries in rats, with females showing stronger contraction and males improved dilation.
Abstract 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 TxA 2 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.
Török et al. (Wed,) conducted a other in Physiological left ventricular hypertrophy. Intensive swim training program vs. Sedentary controls was evaluated on In vitro contractility, endothelium-dependent dilatation, and biomechanical properties of intramural coronary resistance arteries. A 12-week intensive swim training program in rats resulted in an elevated wall-to-lumen ratio and increased wall elastic moduli in coronary resistance arteries, with sex-dependent functional adaptations.