THE GLANDS OF THE STOMACH 



267 



In addition to the chief cells and situated outside of them are other so- 

 called parietal or delomorphous cells. These lie between the chief cells and 

 the membrana propria, but do not form a continuous layer. Just as in the 

 salivary glands, there are fine secretory capillaries between the gland cells. 

 Those belonging to the parietal cells surround them in a basketlike fashion 

 and are connected by cross ducts with the lumen of the 

 gland (Fig. 105). 



It has been known for a long time that the pepsin is 

 formed in the chief cells (Wassman, 1839). 



If small pieces of the fundus mucosa be digested in a 

 warm place with dilute hydrochloric acid, they dissolve leav- 

 ing only small flakes behind. Boiled white of egg digested 

 at 35 40 C. in acidulated water, to which a small piece 

 of the fundic mucosa has been added, dissolves in one to 

 one and one-half hours. 



Since it had been observed further that the pylorus 

 mucosa withstood digestion much longer on similar treat- 

 ment, and since the chief cells had not yet been discov- 

 ered, it was supposed that the fundic glands were the only 

 seat of pepsin production, and that the pyloric glands pro- 

 duced only mucus like the superficial epithelium. It has 

 since been proved that the pyloric glands also produce 

 pepsin. 



Simply to make an extract of pylorus mucosa and dem- 

 onstrate pepsin therein, would not be a fair test, for it 

 might be that the pepsin came from the gastric juice and had 

 only been absorbed by the pyloric mucosa. The matter takes 

 quite another aspect however when we discover that the 

 pyloric mucosa is not completely freed of its pepsin by 

 washing for forty-eight hours in running water. Several 

 other observations show the same thing, and conclusive evi- 

 dence is furnished by the following: By an operation the 

 pyloric portion can be isolated from the rest of the stomach 

 in the same way as has already been described for the 

 fundic portion, and a pyloric fistula be thus established 

 (Klemensiewicz, Heidenhain, Akerman). The animals re- 

 cover and exhibit no sort of disturbance in their general 

 health. From this pyloric sac a fluid is obtained which 

 always contains pepsin even if collected weeks or months 

 after the operation. There can be no question here of absorption from the gas- 

 tric juice. 



We have still to decide, however, whether the pepsin is formed in the 

 chief or the parietal cells of the fundic glands. Several facts indicate 

 the former. 



(1) If freshly isolated fundic glands be warmed in a drop of dilute hydro- 

 chloric acid under the microscope, the chief cells may be seen to disintegrate 

 rapidly, whereas the parietal cells only swell up and become transparent. 

 (2) In sheep embryos it has been observed that the parietal cells appear first 

 in the course of development and the chief cells much later. Pepsin produc- 



- 



FIG. 105. Secretion 

 capillaries s u r - 

 rounding the pa- 

 rietal cells of the 

 gastric glands in 

 a basketlike net- 

 work. The capil- 

 laries also pene- 

 trate the cells, 

 after E. Miiller. 



