DISTRIBUTION OF IMMUNOCOMPETENT CELLS IN VARIOUS AREAS IN THE NORMAL LARYNGEAL MUCOSA OF THE RAT

The larynx can be divided into a supraglottic, a glottic and a subglot tic area, each serving different functions. In many cases of laryngiti s the site of infection is located in one area, leaving other areas un affected. It seems reasonable to speculate that the underlying cause o f the heterogeneous infection pattern in the larynx is the different p rocessing of infectious agents. Therefore, the number and distribution of granulocytes, macrophages, dendritic cells, natural killer cells a nd T and B lymphocytes in the normal laryngeal mucosa of young rats we re studied. The results show that, with the exception of granulocytes, all subpopulations were present in different numbers. Many macrophage s and dendritic cells but only a few natural killer cells and T and B lymphocytes were located in the mucosa. Dendritic cells, natural kille r cells and T and B lymphocytes were rarely present in the vocal fold area, whereas in the subglottic area they were present in high numbers . Thus, differences in the composition of immunocompetent cell populat ions between laryngeal areas were detectable.