Postnatal development of rat vocal folds.
OBJECTIVE
In this study we aimed to determine the feasibility of using a rat model for the study of postnatal vocal fold (VF) development.


METHODS
Eighteen male rats that were 3 days old, 3 weeks old, or 8 months old were analyzed histologically with Alcian blue stain used for detecting hyaluronic acid, elastin-van Gieson stain for elastin, Oil Red O and gold chloride stains for vitamin A-containing lipid droplets, and immunohistochemistry for vimentin (general fibroblast marker) and collagen types I and III.


RESULTS
The macula flava (MF) was observed as a mass of cells that expressed vimentin intensively in the cytoplasm. The MF showed denser hyaluronic acid and collagen type I than did the midmembranous portion of the VF lamina propria. Clear developmental changes were evident in the MF and other regions. The vimentin-positive cells of the 3-day-old MF were mainly oval-shaped and had less cytoplasm, whereas those of the 8-month-old MF were spindle- and stellate-shaped and had more cytoplasm, similar to that reported in humans. Vitamin A-containing lipid droplets were limited to the 3-week-old and 8-month-old MFs and were not present in the 3-day-old VF.


CONCLUSIONS
These results suggest that a rat model is useful in studying VF development and that vitamin A is related to the maturity of the VF.
Division of Otolaryngology-Head and Neck Surgery, University of Wisconsin-Madison, Madison, Wisconsin, USA.
Tomoko
T
Tateya
Ichiro
I
Tateya
Alejandro
A
Munoz-del-Rio
Diane M
DM
Bless
D000818:Animals; D000831:Animals, Newborn; D024042:Collagen Type I / Q000378:metabolism; D024061:Collagen Type III / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism*; D005500:Follow-Up Studies; D006820:Hyaluronic Acid / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344; D014746:Vimentin / Q000378:metabolism; D014801:Vitamin A / Q000378:metabolism; D014827:Vocal Cords / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism
D024042:Collagen Type I; D024061:Collagen Type III; D014746:Vimentin; D014801:Vitamin A; D006820:Hyaluronic Acid