Résumé
A histochemical study of labial glands was performed to compare the different stages of differentiation with those of lingual glands previously studied. Labial glands of 8 to 32 week old human fetuses were analyzed with Hematoxylin/eosine, PAS, Cason, Alcian blue, Toluidine blue, methenamine/silver, TEM and Ruthenium red techniques. At 8-10 weeks various differentiation phases of cell cords originated in the epithelium of the labial mucosa were observed. Acinar buds had PAS positive, alcianophilic and metachromatic material in the lumen of 14 week labial glands. The excretory ducts featured similar characteristics. At 24 weeks groups of mucous and seromucous acini were identified and the mucosubstances increased in the 32 week old fetuses. These results show that the labial glands are histophysiologically differentiated at an earlier stage of development (14 weeks) as compared to lingual glands (20 weeks). However, mucosubstance production would begin during the early phases of embryogenesis for both labial and lingual glands.