title: Cloning and establishment of a line of rats for high levels of voluntary wheel running.
abstract: We generated an original Wistar line of rats that displayed increased levels of wheel running, which we named SPORTS (Spontaneously-Running-Tokushima-Shikoku). Male SPORTS rats ran voluntarily in a running wheel almost six times longer than male control Wistar rats, established without selection for their running activity. The running phenotype of female SPORTS rats was the same as female control Wistar rats. However, male offspring from the cross-mating between a female SPORTS rat and a male control rat also showed a similar level of hyper-running activity as the original SPORTS line. Compared to control rats, male SPORTS rats had lower levels of mean body weight, abdominal fat and plasma insulin after 4 weeks of running. It is likely that all these beneficial changes observed in the SPORTS rats reflected the increases in glucose disposal we observed in oral glucose tolerance tests carried out on the animals. We also found hyper-running caused a significant increase in skeletal muscle oxidative capacity, measured as the ratio of malate dehydrogenase to phosphofructokinase activity, an index of aerobic metabolism. These results indicate that the SPORTS rat may be a good animal model for determining the mechanisms responsible for up-regulation of running motivation, in addition to investigating changes in nutrient metabolism induced by high intensity exercise.
authors.affiliation: Department of Nutrition, School of Medicine, the University of Tokushima, 3-18-15, Tokushima City, 770-8503, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Morishima-Yamato
authors.forename: Fumiko
authors.initials: F
authors.lastname: Hisaoka
authors.forename: Sachiko
authors.initials: S
authors.lastname: Shinomiya
authors.forename: Nagakatsu
authors.initials: N
authors.lastname: Harada
authors.forename: Hideki
authors.initials: H
authors.lastname: Matoba
authors.forename: Akira
authors.initials: A
authors.lastname: Takahashi
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Nakaya
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001947:Breeding / Q000379:methods*; D019976:Cloning, Organism; D005260:Female; D005951:Glucose Tolerance Test; D045022:Lactate Dehydrogenases / Q000378:metabolism; D008291:Malate Dehydrogenase / Q000378:metabolism; D008297:Male; D023421:Models, Animal; D009043:Motor Activity / Q000235:genetics*; D018482:Muscle, Skeletal / Q000201:enzymology; D009210:Myofibrils / Q000201:enzymology; D010375:Pedigree; D025221:Phosphofructokinases / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012420:Running / Q000502:physiology*; D012641:Selection, Genetic
chemical_list: D001786:Blood Glucose; D045022:Lactate Dehydrogenases; D008291:Malate Dehydrogenase; D025221:Phosphofructokinases