Roles of vitamin A and macula flava in maintaining vocal folds.
OBJECTIVE
Vitamin A plays important roles in development, growth, and regeneration. Vitamin A-storing stellate cells have been identified in several organs. The functional roles of vitamin A in the vocal folds are still unknown, although vitamin A-storing vocal fold stellate cells have been observed in the macula flava of human and rat vocal folds. The purpose of this study was to investigate the roles of vitamin A in vocal folds.


METHODS
Vitamin A-deficient rats were generated, and the vocal folds were examined histologically. Messenger RNA was extracted from the vocal folds and analyzed by real-time polymerase chain reaction.


RESULTS
Immunohistochemical analysis of normal vocal folds revealed expression of retinoic acid receptor a in vocal fold stellate cells. The cells in the macula flava of vitamin A-deficient rats showed a larger nucleus/cytoplasm ratio than did those of vitamin A-sufficient rats, but messenger RNA expression of major extracellular matrix components in the macula flava of vitamin A-deficient rats did not present a remarkable change except for procollagen type I. Expression of hyaluronic acid, collagen types I and III, and elastin did not show a significant change in vitamin A-deficient rat vocal folds.


CONCLUSIONS
These results indicate that vitamin A is not essential to maintaining the extracellular matrix of normal adult vocal folds, although vocal fold stellate cells participate in vitamin A storage.
Tateya
Tomoko
T
Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Japan.
Tateya
Ichiro
I
Surles
Rebecca Lynn
RL
Tanumihardjo
Sherry
S
Bless
Diane M
DM
D000818:Animals; D005260:Female; D018507:Gene Expression Regulation, Developmental; D011247:Pregnancy; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D018168:Receptors, Retinoic Acid / Q000096:biosynthesis / Q000235:genetics; D000072482:Retinoic Acid Receptor alpha; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014801:Vitamin A / Q000494:pharmacology*; D014802:Vitamin A Deficiency / Q000188:drug therapy / Q000235:genetics; D014815:Vitamins / Q000494:pharmacology*; D014827:Vocal Cords / Q000187:drug effects / Q000196:embryology* / Q000378:metabolism
C000607071:RARA protein, human; D012333:RNA, Messenger; C000607073:Rara protein, rat; D018168:Receptors, Retinoic Acid; D000072482:Retinoic Acid Receptor alpha; D014815:Vitamins; C082925:retinoic acid receptor beta; D014801:Vitamin A