Reactivity of Isolated Arteries After 5-Week-Lasting Period of Intermittent Fasting Followed by the Return to Ad Libitum Regimen in Healthy Rats Fed With Normal and High-Fat Diet

Intermittent fasting (IF) represents one of the dietary regimens being effectively used in non-pharmacological prevention and treatment of cardiometabolic disorders. The aim of the present study was to detect the retained alterations at the level of arterial function caused by a 5-week-lasting period of IF in adult male Wistar-Kyoto rats after their switching back to ordinary feeding (4 weeks of ad libitum regimen). The rats were administered a diet containing normal or high percentage of fat. Control rat groups were fed continuously ad libitum. The decreased weekly calorie intake in rats during IF period was associated with the discontinuation of body weight gain, irrespective of the type of diet; moreover, rats fed with a high-fat diet had significantly increased systolic blood pressure in comparison with the other groups. At the end of the experiment, large and small arteries were isolated from the rats and arterial rings with intact or removed perivascular adipose tissue (PVAT) were prepared for isometric tension recording. In the rat groups exposed to IF period, the aorta rings with intact PVAT showed a significant increase in relaxation responses when compared to groups without IF. The effect of IF was also manifested in the increase in sensitivity of arterial preparations to noradrenaline which was, however, mostly attenuated by the enhanced anticontractile influence of PVAT. These results indicate that the improvement of PVAT properties could represent one of the mechanisms by which IF-induced beneficial effects on vascular function might be preserved even after the return to ad libitum regimen.