Force Deficits After Active Stretches of Rat Skeletal Muscles with Reduced Collagen Cross-Links

Details

• Personal Author:
  Stauber WT ; Willems MET
• Description:
  Sprague Dawley rats ( n=6, age 87 days) were injected 2x daily for 43 days with P-aminopropionitrile (BAPN, 333 mg*kg-1*day-1 i.p.) which inhibits the enzyme, lysyl oxidase, responsible for collagen cross-links. Age-matched saline-injected rats served as controls (C, n=6). Isometric forces before dorsiflexion (a = 30000 degrees -s*-2, ankle position 90 degrees to 40 degrees) with repeated stretches (20) of active plantar flexor muscles at 80 Hz (contraction time 1.1 s, rest periods 3 min) were measured. Isometric forces were measured at 90 degrees, before and 1 hr after the stretches at 5, 10, 20, 40, 60 and 80 Hz. Relative weights of soleus, plantaris and gastrocnemius muscles were not different between groups. Significant reductions in collagen cross-links, pyridinoline, (mol/mol collagen) were found in tendon (22.9%), plantaris (17.1%), and soleus (7.4%) with no changes in collagen content (hydroxyproline) as determined by HPLC. In gastrocnemius medialis, pyridinoline cross-links were 4.4% lower but this did not pass significance (P = 0.2). Groups had similar isometric forces at 5, 10, 20, 40, 60 and 80 Hz before the stretches. Isometric force deficits that developed followed similar courses for BAPN- and C-rats. Before the last stretch, deficits were 51.1 % +/- 2.4% (C) and 54.7 % +/- 4.6% (BAPN). After 1 hr of rest following the stretches, deficits were similar at 80, 60, 40 and 20 Hz but were 26% and 29% larger at 10 and 5 Hz in BAPN-rats (P < 0.05). Isometric force deficits after active stretches of rat plantar flexor muscles with reduced collagen cross-links, pyridinoline, were larger only at low stimulation frequencies. [Description provided by NIOSH]
• Subjects:
  Animals Laboratories Musculoskeletal System Occupational Health Safety
• Keywords:
  Animal Studies Laboratory Animals Muscles Skeletal System
• ISSN:
  0031-9376
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Abstract or Summary
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  43
• Issue:
  4
• NIOSHTIC Number:
  nn:20029760
• Citation:
  Physiologist 2000 Aug; 43(4):367
• Federal Fiscal Year:
  2000
• NORA Priority Area:
  Disease and Injury: Musculoskeletal Disorders of the Upper Extremities
• Performing Organization:
  West Virginia University, Morgantown, West Virginia
• Peer Reviewed:
  False
• Start Date:
  19920101
• Source Full Name:
  The Physiologist
• End Date:
  20050531
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:6aa305cc7aae510ffb2ac1f459146167d8c5e778a47a4e3d115d21f714f0de48fec19e84b35b63c74f16739554b014bd9b9c61b9e904951b7dcfdbde3077295e
• Download URL:
  https://stacks.cdc.gov/view/cdc/190677/cdc_190677_DS1.pdf
• File Type:
  [PDF - 225.74 KB ]