Free access to running wheels abolishes hyperphagia in human growth hormone transgenic rats.
Obesity is a major health problem, and increased food intake and decreased physical activity are considered as two major factors causing obesity. Previous studies show that voluntary exercise in a running wheel decreases not only body weight but also food intake of rats. We previously produced human growth hormone transgenic (TG) rats, which are characterized by severe hyperphagia and obesity. To gain more insight into the effects on physical activity to food consumption and obesity, we examined whether voluntary running wheel exercise causes inhibition of hyperphagia and alteration of body composition in TG rats. Free access to running wheels completely abolished hyperphagia in TG rats, and this effect persisted for many weeks as far as the running wheel is accessible. Unexpectedly, though the running distances of TG rats were significantly less than those of wild type rats, it was sufficient to normalize their food consumption. This raises the possibility that rearing environment, which enables them to access to a running wheel freely, rather than the amounts of physical exercises is more important for the maintenance of proper food intake.
Department of Veterinary Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Mugiko
M
Komatsuda
Keitaro
K
Yamanouchi
Takashi
T
Matsuwaki
Masugi
M
Nishihara
D000375:Aging; D000818:Animals; D001835:Body Weight; D005247:Feeding Behavior; D005786:Gene Expression Regulation / Q000502:physiology*; D019382:Human Growth Hormone / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D006963:Hyperphagia / Q000235:genetics / Q000378:metabolism* / Q000517:prevention & control*; D009043:Motor Activity / Q000502:physiology*; D010805:Physical Conditioning, Animal; D051381:Rats; D055647:Rats, Transgenic
D019382:Human Growth Hormone