Proventricular Glands in Fowl

Some researchers have already described the fowl proventriculus. However, we believed there was a need for detailed carbohydrate histochemicaT nvestigations on the same glands. Moreover, some researchers had erred about the lamina muscularis mucosae. The results of these investigations are as follows.1. The proventricular glands consist of both superficial and profound gastric glands.2. The superficial glands are distributed in the lamina propria mucosae while the profound glands exist in the tela submucosa.3. The superficial glands are simple, branched tubular glands. The columnar glandular cells are arranged in a simple layer and react strongly to PAS, AB (pH 2.5 and 0.5). These appear to be dark purple when they are stained with PAS-AB (pH 2.5). Some other methods have also been tried (Table 1).4. Judging from the data 3), the superficial gastric glands contain neutral, weak and strong acids, sulfuric and acid mucopolysaccharides, sialomucin, and II and III neutral mucus type.5. Glandulur cells in the body and basal portions of the superficial gastric glands contain a large number of fine pepsinogen granules.6. Judging from the data of 3)-5), we believe that the superficial gastric glands are undifferentiated gastric glands and that they are same kinds of glands that are found in mammals.7. A large number of profound gastric glands fill the tela submucosa. They are compound tubular glands, and are composed of many glandular alveoli. Their columnar glandular cells are arranged in a simple layer.8. These glandular cells react moderately to PAS, negatively to M3 (pH 2.5 and 0.5) and PAS-AB (pH 2.5). Moreover, we observed some other reactions (Table 1).9. Judging from the data 8), the profound gastric glands contain a small quantity of neutral polysaccharide; however, sulfuric and acid mucopolysaccharides, and type II and DI neutral mucous are found in extremely small quantities and have no sialomucin, or either weak or strong acid mucopolysaccharides.10. The alveolar cells in the above glands contain a large number of coarse pepsinogen granules.11. Judging from the data 8)-10), profound gastric glands possess the characteristics of differentiated gastric glands.12. Our investigations showed that the differentiated gastric glands in many kinds of mammals (including humans) and reptiles are simple, branched tubular glands, which exist in the lamina propria mucosae. At the same time, the glands in birds are compound tubular glands which gather in the tela submucosa. Namely, the construction and region of the same glands in birds are very different from those in mammals and reptiles.13. Some researchers believe that the profound gastric glands of fowl are in the lamina propria mucosae, while others believe that these glands exist between the two strata of the muscularis mucosae. However, both are mistaken.v14. The gastric glands in mammals (including humans) possess parietal cells, while the above-mentioned glands of birds and reptiles do not have these parietal cells.