Related Experiment Videos
Diaphragmatic muscle fiber type development in swine
D E Mayock1, J Hall, J F Watchko
1Department of Pediatrics, University of Washington, School of Medicine, Seattle 98195.
Pediatric Research
|October 1, 1987
Summary
Swine diaphragm muscle develops distinct fiber types by 6 months, with type I fibers increasing and type IIA decreasing. Muscle fiber size grows with age, indicating continued development beyond initial differentiation.
Area of Science:
- Muscle physiology
- Developmental biology
- Histochemistry
Background:
- The diaphragm is crucial for respiration.
- Understanding diaphragmatic muscle development is key to respiratory health.
- Swine models offer insights into mammalian muscle maturation.
Purpose of the Study:
- To analyze changes in swine diaphragm muscle fiber types and size across postnatal development.
- To compare fiber type composition between costal and crural diaphragm segments.
- To establish the timeline for diaphragm muscle differentiation in pigs.
Main Methods:
- Enzyme histochemistry for adenosine triphosphatase and reduced nicotinamide adenine dinucleotide.
- Analysis of diaphragmatic muscle fiber types in costal and crural segments.
- Assessment at four postnatal ages: 1 day, 1 month, 6 months, and 3-6 years.
Main Results:
- Type I fibers increased, while type IIA fibers decreased from birth to 6 months.
- Type IIB fibers increased, and type IIC fibers were transient, disappearing by adulthood.
- Crural segments showed a higher proportion of type I fibers; all fiber types increased in cross-sectional area with age.
Conclusions:
- Swine diaphragm muscle differentiates into its adult form by 6 months of age.
- While fiber type composition stabilizes, fiber size continues to increase with body growth.
- These findings provide a developmental profile of the porcine diaphragm muscle.