The Effect of Chronic Exercise on Vascular and Kidney Responses in the Wistar-Kyoto Rat

One of the leading causes of cardiovascular disease is hypertension. Failure of the kidney to remove excess sodium and water from the body as blood pressure rises can result in hypertension. Regular exercise has been proven to reduce blood pressure in both humans and rats. In addition, exercise has been shown to reduce the development of atherosclerotic plaques, body weight, resting heart rate, and alter hormone levels towards normal homeostasis levels. Previous research has not examined the effect of exercise on kidney sodium excretion in response to hypertension. The current study involved a total of forty Wistar-Kyoto (WKY) rats, twenty males and twenty females, which were randomly placed into either exercise or sedentary groups. The exercise group was provided a running wheel from weaning to 12-14 weeks of age. The sedentary group had no exercise. At 12-14 weeks of age the rats were anesthetized (Inactin, 100 mg/ kg). A breathing tube was surgically placed into the trachea, and catheters were placed into the carotid artery (to monitor blood pressure and heart rate) and jugular vein (for infuse of saline to maintain fluid balance). A collecting tube was inserted into the bladder for urine collection. After a 15 minute baseline period, which included a urine collection, blood pressure was artificially raised by tying off the celiac, mesenteric, and lower abdominal aorta. Blood pressure was monitored, and urine was collected for four additional 15-minute intervals. The sodium and potassium excretion in the urine were analyzed and compared between the two groups of rats