The Effect of 12 Weeks of Endurance Training on Plasma Levels of Acylated Ghrelin, PYY3-36, Food Intake and Weight of Obese Male Rats

Due to an increase in obesity, the aim of the present study was to examine the effect of 12 weeks of endurance training on body weight, food intake, plasma acylated ghrelin and PYY3-36 in obese male rats. 16 male Wistar rats were fed for 9 weeks with a high fat diet (derived from soybean oil) until they reached mean weight of 319±30 g. The rats were randomly divided into control group (n=8) and training group (n=8) (60 minutes of running on a treadmill (grade=0) per session, 15 to 30 m./min., 5 days per week for 12 weeks). The rats were provided with standard food and water ad libitum and every two days, food intake and weight were measured and recorded. Blood samples were collected 24 hours after the last training session and 8 hours of overnight fasting. The ELISA method was used to measure plasma concentration of mentioned hormones. Independent t test showed that the 12 weeks of endurance training significantly decrease in the weight of training group (P=0.001) compared with the control group. During the training period, the mean food intake of training group was significantly lower than control group (p=0.028). There was no significant difference in plasma concentration of acylated ghrelin between the two groups, but plasma levels of PYY 3-36 in the exercise group was significantly higher (p=0.016). It seems that one of the mechanisms of weight loss as a result of endurance training is reduced food intake by increasing plasma levels of PYY3-36.