Habitual, moderate exercise is associated with improved health, including reductions in illness. These benefits may stem, in part, from immune function improvements. We have previously reported that daily wheel running increases serum and peritoneal natural IgM (nIgM) in pathogen-free Sprague-Dawely rats. B-1 cells, which primarily reside in the peritoneal cavity, produce nIgM in the absence of...

This study extended to treadmill exercise training our prior report (Dishman RK, Warren JM, Youngstedt SD, Yoo H, Bunnell BN, Mougey EH, Meyerhoff JL, Jaso-Friedmann L, and Evans DL. J Appl Physiol 78: 1547-1554, 1995) that activity wheel running abolished the suppression of footshock-induced natural killer (NK) cell cytolysis. Twenty-four male Fischer 344 rats were assigned to one of three gro...

The behavioral consequences of uncontrollable stress, or learned helplessness (LH) behaviors, are thought to involve hyperactivity of serotonergic (5-HT) neurons in the dorsal raphe nucleus (DRN). Other brain regions implicated in LH and capable of affecting 5-HT systems, such as the bed nucleus of the stria terminalis (BNST), amygdala, and habenula, could contribute to DRN 5-HT hyperactivity d...

The onset of the daily wheel running bout precedes dark onset by several hours in the early runner genetic variant of mice. Here, we test the hypothesis that timed daily administration of a melatonin agonist, ramelteon, or a benzodiazepine, triazolam, normalizes the timing of daily wheel-running rhythms in early runner mice. The daily profiles of wheel-running activity of early runner mice were...

Motivation and ability both underlie voluntary exercise, each with a potentially unique genetic architecture. Muscle structure and function are one of many morphological and physiological systems acting to simultaneously determine exercise ability. We generated a large (n = 815) advanced intercross line of mice (G4) derived from a line selectively bred for increased wheel running (high runner) ...

Studies that have found a positive influence of moderate, nonexhaustive exercise on life expectancy contradict the rate-of-living theory, which predicts that high energy expenditure in exercising animals should shorten life. We investigated effects of exercise on energy metabolism and life span in male mice from lines that had been selectively bred for high voluntary wheel-running activity and ...

To evaluate the effects of lutein-fortified milk administration on running exercise, a voluntary wheel-running model was performed in rats. Four-week-old F344 rats were administered test milk (10 mL/kg) daily following a 4-h fasting period, and their running distances were measured each day for a 9-week period. Total weekly running distance significantly increased from the sixth week until the ...

Otsuka Long-Evans Tokushima fatty (OLETF) rats lacking cholecystokinin-A receptors are hyperphagic, obese, and diabetic. Although exercise attenuates OLETF rats' obesity, the mechanisms underlying the effects of exercise are unclear. In this study, we determined the effects of running wheel activity on patterns of body weight gain, food intake, and hypothalamic gene expression. We demonstrate t...