Age-related blood flow changes in the rat intrinsic laryngeal muscles.

ABSTRACT

CONCLUSIONS: These results indicate that a deceased laryngeal blood flow (BF) could be one contributing factor to age-related phonatory and airway dysfunction. OBJECTIVE: Studies of non-laryngeal muscles suggest that decreased BF may contribute to an age-related decline in muscle performance. We hypothesized that there is an age-related BF decrease to the intrinsic laryngeal muscles. MATERIALS AND METHODS: Intrinsic laryngeal muscle BF was measured in young (3-6 months old; n=11) and old (28-30 months old; n=21) male Fischer 344 rats during quiet respiration using the radiolabeled microsphere technique. RESULTS: BF to the posterior cricoarytenoid (PCA) was very high even during this submaximal recruitment, consistent with its specialization for oxidative metabolism and fatigue resistance. The results demonstrated significant (p<0.05) age-related BF decreases in the thyroarytenoid (young, 163; old, 64 ml/min/100 g), cricothyroid (young, 104; old, 52 ml/min/100 g), and PCA (young, 404; old, 235 ml/min/100 g).