Dynamic functional and ultrastructural changes of gastric parietal cells induced by water immersion-restraint stress in rats.
OBJECTIVE
To investigate the dynamic functional and ultrastructural changes of gastric parietal cells induced by water immersion-restraint stress (WRS) in rats.


METHODS
WRS model of Sprague-Dawley (SD) rats was established. Fifty-six male SD rats were randomly divided into control group, stress group and post-stress group. The stress group was divided into 1, 2 and 4 h stress subgroups. The post-stress group was divided into 24, 48 and 72 h subgroups. The pH value of gastric juice, ulcer index (UI) of gastric mucosa and H(+), K(+)-ATPase activity of gastric parietal cells were measured. Ultrastructural change of parietal cells was observed under transmission electron microscope (TEM).


RESULTS
The pH value of gastric juice decreased time-dependently in stress group and increased in post-stress group. The H(+), K(+)-ATPase activity of gastric parietal cells and the UI of gastric mucosa increased time-dependently in stress group and decreased in post-stress group. Compared to control group, the pH value decreased remarkably (P = 0.0001), the UI and H(+), K(+)-ATPase activity increased significantly (P = 0.0001, P = 0.0174) in 4 h stress subgroup. UI was positively related with stress time (r = 0.9876, P < 0.01) but negatively with pH value (r = -0.8724, P < 0.05). The parietal cells became active in stress group, especially in 4 h stress subgroup, in which plenty of intracellular canalicular and mitochondria were observed under TEM. In post-stress group, the parietal cells recovered to resting state.


CONCLUSIONS
The acid secretion of parietal cells is consistent with their ultrastructural changes during the development and healing of stress ulcer induced by WRS and the degree of gastric mucosal lesions, suggesting gastric acid play an important role in the development of stress ulcer and is closely related with the recovery of gastric mucosal lesions induced by WRS.
Li
Yu-Mei
YM
Department of Gastroenterology, Hospital of Zhejiang Armed Police Forces Crops, Jiaxin, Zhejiang Province, China. li.yumei@sohu.com
Lu
Guo-Ming
GM
Zou
Xiao-Ping
XP
Li
Zhao-Shen
ZS
Peng
Gui-Yong
GY
Fang
Dian-Chun
DC
D000818:Animals; D004195:Disease Models, Animal; D005744:Gastric Acid / Q000378:metabolism / Q000502:physiology; D005753:Gastric Mucosa / Q000201:enzymology / Q000473:pathology / Q000503:physiopathology / Q000648:ultrastructure; D017506:H(+)-K(+)-Exchanging ATPase / Q000032:analysis / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D007101:Immersion / Q000009:adverse effects; D008297:Male; D008854:Microscopy, Electron; D010295:Parietal Cells, Gastric / Q000378:metabolism* / Q000648:ultrastructure; D051381:Rats; D017207:Rats, Sprague-Dawley; D012149:Restraint, Physical / Q000009:adverse effects; D012720:Severity of Illness Index; D013276:Stomach Ulcer / Q000201:enzymology / Q000473:pathology / Q000503:physiopathology / Q000523:psychology; D013312:Stress, Physiological / Q000473:pathology* / Q000503:physiopathology*
D017506:H(+)-K(+)-Exchanging ATPase