Abstract
BackgroundWe aimed to identify sex differences in the network properties and to recognize the geometric alteration effects of long-term swim training in a rat model of exercise-induced left ventricular (LV) hypertrophy.MethodsThirty-eight Wistar rats were divided into four groups: male sedentary, female sedentary, male exercised and female exercised. After training sessions, LV morphology and function were checked by echocardiography. The geometry of the left coronary artery system was analysed on pressure-perfused, microsurgically prepared resistance artery networks using in situ video microscopy. All segments over > 80 μm in diameter were studied using divided 50-μm-long cylindrical ring units of the networks. Oxidative-nitrative (O-N) stress markers, adenosine A2A and estrogen receptor (ER) were investigated by immunohistochemistry.ResultsThe LV mass index, ejection fraction and fractional shortening significantly increased in exercised animals. We found substantial sex differences in the coronary network in the control groups and in the swim-trained animals. Ring frequency spectra were significantly different between male and female animals in both the sedentary and trained groups. The thickness of the wall was higher in males as a result of training. There were elevations in the populations of 200- and 400-μm vessel units in males; the thinner ones developed farther and the thicker ones closer to the orifice. In females, a new population of 200- to 250-μm vessels appeared unusually close to the orifice.ConclusionsPhysical activity and LV hypertrophy were accompanied by a remodelling of coronary resistance artery network geometry that was different in both sexes.
Highlights
We aimed to identify sex differences in the network properties and to recognize the geometric alteration effects of long-term swim training in a rat model of exercise-induced left ventricular (LV) hypertrophy
We show how the intramural resistance coronary artery network running underneath the surface of the rat heart is altered after 12 weeks of swim training and what differences can be detected between males and females
The calculated LV mass index determined by echocardiography indicated cardiac hypertrophy in both exercised groups compared with control animals (Table 1)
Summary
We aimed to identify sex differences in the network properties and to recognize the geometric alteration effects of long-term swim training in a rat model of exercise-induced left ventricular (LV) hypertrophy. The network geometry of the coronary arteries is very important in determining blood flow, but the methodical techniques for examining geometric properties are very difficult and expensive. Only larger conduit arteries can be examined with these methods. Network remodeling of intramural coronary resistance arteries in aged rats and in hypertensive female rats was analysed with micropreparation and in situ video microscopic recording by Nádasy et al [6, 7]. The questions of whether the network geometry adapted as a result of long-term exercise training and whether there are any differences in long-term exercise-induced coronary resistance artery network remodeling between the two sexes were addressed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
