Voluntary resistance exercise training with obese and lean Zucker rats

Details

• Personal Author:
  Bryner RW ; Hall I ; Peterson JM ; Wirth, Oliver
• Description:
  PURPOSE: Fatty Zucker rats have been used to examine the effects of obesity, and diabetes on the physiological mechanisms associated with exercise-induced musculosketetal adaptation. Because many volitional exercise models use operant conditioning techniques that rely on dietary restrictions to sufficiently motivate voluntary behavior, a study was conducted to determine if obese Zucker rats could be trained to perform a voluntary weight-lifting movement without altering their diet. METHODS: Using a custom-designed hind limb loading apparatus, eight 6-weekold male genetically obese Zucker rats (fa/fa) and eight Zucker lean rats (+/fa) were trained with positive reinforcement to enter a vertical tube, insert their head into a neck ring, and repeatedly lift and lower their body weight in a movement that targeted the plantar flexor muscle group. Training sessions were conducted 5 days per week and each lasted until at least 50 lifting and lowering movements were performed or 1.5 hrs. One 45-mg sucrose pellet was given as a reinforcer, after every second lift. Food and water were available in the home cage at all times. RESULTS: As expected, mean body weights increased rapidly in the obese rats from 201 g at 6 weeks old to 789 g at 23 weeks old. During the same period mean body weights of the Zucker leans increased from 183 g to 457 g. All rats successfully acquired the weight-lifting movement. However, of the obese Zucker rats only 2 were able to approach the goal of 50 lifts per session with a mean of 47 lifts per session. The mean lifts per session for the remaining 6 obese rats ranged from 5 to 25. 5 of 8 lean Zucker rats were able to approach the 50-lifts/session goal with a mean range of 47-51. The 3 other lean rats recorded means of 28, 30, 35, lifts per session, respectively. CONCLUSIONS: Results demonstrate that genetically obese Zucker rats can be trained to perform a voluntary movement for reward. However, food reward was unable to continually motivate the Zucker obese rats towards a goal of 50-body weight lifts per day. Conversely, it was sufficient to elicit continual lifting of Zucker leans. In summary the procedures used in this study were not sufficient to maintain a consistent lifting pattern in obese Zucker rats. [Description provided by NIOSH]
• Subjects:
  Animals Behavior Body Weight Diet Laboratories Musculoskeletal System Occupational Health Safety
• Keywords:
  Body-weight Dietary-effects Laboratory-animals Muscles Musculoskeletal-system Physical-capacity Physical-exercise Physical-fitness Physical-reactions Physiological-effects Physiological-factors Physiological-function Physiology Weight-factors

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• ISSN:
  0195-9131
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  37
• Issue:
  5
• NIOSHTIC Number:
  nn:20044038
• Citation:
  Med Sci Sports Exerc 2005 May; 37(5)(Suppl 1):S189
• Email:
  rbryner@hsc.wvu.edu
• Federal Fiscal Year:
  2005
• Peer Reviewed:
  False
• Source Full Name:
  Medicine and Science in Sports and Exercise
• Supplement:
  1
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:9dc88320627d26800a1a6c7dabfd0c4677281de382c9692da50bb03d72c9898f6adda7ebce6cf93a4ac30b2eb6d36240db3648cc189583e28d9618f75664ab7c
• Download URL:
  https://stacks.cdc.gov/view/cdc/199892/cdc_199892_DS1.pdf
• File Type:
  [PDF - 38.86 KB ]