Abstract:
BACKGROUND: Capillaries function to provide a surface area for nutrient and waste exchange
with cells. The capillary supply of skeletal muscle is highly organized, and therefore, represents
an excellent choice to study factors regulating diffusion. Muscle is comprised of three specific
fibre types, each with specific contractile and metabolic characteristics, which influence the
capillary supply of a given muscle; in addition, both environmental and genetic factors influence
the capillary supply, including aging, physical training, and various disease processes.
OBJECTIVE: The present study was undertaken to develop and assess the functionality of a
data base, from which virtual experiments can be conducted on the capillary supply of human
muscle, and the adaptations of the capillary bed in muscle to various perturbations.
METHODS: To create the database, an extensive search of the literature was conducted using
various search engines, and the three key words - "capillary, muscle, and human". This search
yielded 169 papers from which the data for the 46 variables on the capillary supply and fibre
characteristics of muscle were extracted for inclusion in the database. A series of statistical
analyses (ANOVA) were done on the capillary database to examine differences in skeletal
muscle capillarization and fibre characteristics between young and old individuals, between
healthy and diseased individuals, and between untrained, endurance trained, endurance welltrained,
and resistance trained individuals, using SAS. RESULTS: There was a significantly
higher capillarization in the young compared to the old individuals, in the healthy compared to
the diseased individuals, and in the endurance-trained and endurance well-trained compared to
the untrained individuals. CONCLUSIONS: The results of this study support the conclusion
that the capillary supply of skeletal muscle is closely regulated by factors aimed at optimizing
oxygen and nutrient supply and/or waste removal in response to changes in muscle mass and/or
metabolic activity.
