In experiments involving primates, e.g. before and after spaceflight, needle biopsies were thought to be a logical and feasible means of obtaining metabolic and morphological information from skeletal muscles. However, the feasibility of obtaining consistent, repeatable biopsies from individual muscles had to be demonstrated prior to the acceptance of this procedure. To study this approach, the architectural properties and the fiber type distributions at three levels and two regions along the proximodistal axis of the soleus, medial gastrocnemius and tibialis anterior of adult rhesus monkeys were determined. In each muscle, biopsies were taken from specific regions where the fiber type distribution was determined. Within each region of each muscle the fiber type populations were similar at the three levels studied. The percentage of fast or oxidative fibers in the biopsies and in the regions of the same muscle were highly correlated i. e. r = 0.98 for both comparisons. In addition based on normalized values (z scores) 25/26 and 22/26 biopsies were within the 95% confidence interval, i.e. the biopsies were a representative sample of the mean fiber type population of that region of the muscle. In all muscles the mean fiber lengths were no more than one third the length of the muscle. Together, these data indicate the feasibility of obtaining independent, repeated biopsies having similar fiber types from each of the muscles studied.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.