Research for the regulation of voluntary exercise and energy metabolism by appetite-regulating factors

我们建立了一种新的动物模型，即自发性跑德岛四国大鼠，它表现出高自发性跑轮和低血浆总胃饥饿素水平。本研究的目的是利用sport动物模型，研究胃饥饿素（Ghrelin）和肥胖抑制素（Obestatin）对自主轮跑和能量代谢的体内影响。我们将运动大鼠分为两组，分别肌肉注射生理盐水、胃饥饿素或胃饥饿素+肥胖抑制素6天(100。g/ kg BW/ day)。在胃饥饿素组，自愿跑轮明显减少。胃饥饿素组的食物摄入量、体重和腹部内脏脂肪显著增加。肥胖抑制素抑制了胃饥饿素诱导的食物摄入、体重和腹部内脏脂肪的增加，但对自愿跑轮没有任何影响。我们的研究结果表明，Ghrelin和Obestatin可能在自愿运动或食欲方面发挥不同的途径。一些食欲调节因子可能调节自发运动或能量代谢。

We established a new animal model called SPORTS(Spontaneously-Running Tokushima-Shikoku) rats, which show high voluntary wheel running and low level of plasma total Ghrelin. The aim of this study was to investigate the in vivo effect of Ghrelin and Obestatin, which are appetite-regulating factors generated from prepro-Ghrelin, on voluntary wheel running and energy metabolism using the SPORTS animal model. We divided SPORTS rats into two groups, which were intramuscularly administrated Saline, Ghrelin, or Ghrelin+ Obestatin for six days(100. g/ kg BW/ day). Voluntary wheel running was significantly decreased in Ghrelin groups. Food intake, body weight, and abdominal visceral fat were significantly increased in Ghrelin groups. Obestatin suppressed Ghrelin-induced food intake, body weight, and abdominal visceral fat gains, but did not have any effect on voluntary wheel running. Our results suggest that Ghrelin and Obestatin may exert different pathway on the voluntary exercise or appetite. Some appetite-regulating factors may regulate voluntary exercise or energy metabolism.