Stereological estimates indicate that aging does not alter the capillary length density in the human posterior cricoarytenoid muscle

• Published in: Journal of applied physiology (1985) 2007-11, Vol.103 (5), p.1815-1823
• Main Authors: Lyon, Michael J, Steer, Linda M, Malmgren, Leslie T
• Format: Article
• Language: English
• Subjects: Adult; Age Factors; Aged; Aged, 80 and over; Aging; Aging - pathology; Biological and medical sciences; Blood vessels; Capillaries - pathology; Female; Fundamental and applied biological sciences. Psychology; Humans; Laryngeal Muscles - blood supply; Laryngeal Muscles - pathology; Male; Microscopy, Confocal; Middle Aged; Muscle Fibers, Fast-Twitch - pathology; Muscle Fibers, Slow-Twitch - pathology; Muscular Atrophy - pathology; Musculoskeletal system; Research Design; Tissues
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/japplphysiol.00030.2007

1 Otolaryngology and Communication Sciences, and 2 Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York Submitted 8 January 2007 ; accepted in final form 30 July 2007 Studies of some human skeletal muscles demonstrate an age-related capillarity decrease. An age-related decrease in blood flow to the posterior cricoarytenoid muscle (PCA) in rats has been reported, as well as a decreased ability to abduct the vocal folds. We, therefore, hypothesized that decreased muscle capillarity may contribute to PCA dysfunction in the elderly. Using immunological and stereological techniques, human PCAs (ages 18–98 yr; 28 men, 23 women) were examined for age-related changes in muscle fiber-type-specific and/or total capillary length density. While analysis shows no age-related changes in total muscle or fiber-type-specific capillary length densities ( L V cap ), there are significant age-related increases in L V cap within the interstitial tissue ( P = 0.001) and in the ratio of the type I L V cap to type I surface ( P = 0.002), with a strong trend for type II L V cap ( P = 0.055). There is also an age-related decrease in the muscle fiber surface density for both type I and II fibers ( P < 0.001 and 0.04, respectively). Data also show that women have a significantly higher type II L V cap ( P = 0.039), regardless of age. In addition, with the exception of female type I L V cap , all measured variables are significantly higher for type I fibers ( P < 0.001), independent of age or sex. While data indicate there are age-related changes of capillary-muscle fiber relationships within the PCA, they do not support the hypothesis of an age-related loss of capillarity. blood supply; larynx; microvascular; blood-tissue exchange Address for reprint requests and other correspondence: Michael J. Lyon, Dept. of Otolaryngology and Communication Sciences, SUNY Upstate Medical Univ., 750 East Adams St., Syracuse, New York 13210 (e-mail: lyonm{at}upstate.edu )