TREADMILL EXERCISE PERFORMANCE BY THE AGEING IRRADIATED RAT.
Abstract
The ability of male Sprague-Dawley rats irradiated as young adults to perform on an inclined treadmill was evaluated at 3, 10, 16, 22, and 28 months of age. Irradiated groups received whole-body sublethal (30-day) or lethal-range doses of x-rays (430 or 680 RADS) or fast neutrons (230 or 320 rads) after the first treadmill tests. In spite of reductions in treadmill speed, the proportion of the control group which completed the task declined gradually through the first two years, then decreased markedly at 28 months. The gradual progressive decrement in the proportion of the group which completed the task was also apparent in the irradiated animals but the rapid deterioration in performance ability occurred at 22 months of age. The terminal deterioration appears associated with approaching death, and its earlier appearance in irradiated groups is associated with radiation-induced lifespan shortening. For those control animals able to complete the task, there was an abrupt rise in heart rate with the onset of exercise, little or no change during the remainder of the one-hour exercise period, and a return to pre-exercise levels within a half-hour after cessation. The pattern of heart rate with exercise was not markedly affected by age and only occasional differences between irradiated and control groups were noted. Although colonic temperature increased with the initiation of exercise at all ages, the pattern during the remainder of exercise varied with age at the time of test. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 05, 1966
- Accession Number
- AD0635251
Entities
People
- Dave C. Jones
- Donald J. Kimeldorf
- Garold K. Osborn
Organizations
- Naval Radiological Defense Laboratory