Dynamic functional and ultrastructural changes of gastric parietal cells induced by water immersion-restraint stress in rats

Figure 1 pH value of gastric juice in all groups. ^bP < 0.01 vs normal group; ^dP < 0.01 vs stress 4 h group.

Figure 2 Ulcer index (UI) of gastric mucosa in all groups. ^bP < 0.01 vs normal group; ^dP < 0.01 vs stress 4 h group.

Figure 3 H⁺, K⁺-ATPase activity of parietal cells in all groups. ^aP < 0.05 vs normal group; ^cP < 0.05 vs stress 4 h group.

Figure 4 Ultrastructural change of parietal cells. A: Gastric parietal cells presented resting state, abundant tubulovesicles and few intracellular canaliculi lined with rare microvilli could be found in the cytoplasm in normal group (×12 000); B: Parietal cells presented pre-secreting state, intracellular canaliculi lined with short microvilli were observed, plenty of vesicles were located around the canaliculi and accumulated on the apical plasma membrane in 1 h WRS group (×12 000); C: Parietal cells presented secreting state with decreased vesicles and increased intracellular canaliculi lined with elongated microvilli in 2 h WRS group; D: Parietal cells presented active secreting state and cytoplasm was almost devoid of vesicles and intracellular canalicular lumen contained numerous elongated microvilli in 4 h WRS group (×12 000); E - G: at 24, 48 and 72 h at the end of WRS for 4 h, Parietal cells returned to resting state with abundant tubulovesicles and few canaliculi in cytoplasm in post-stress group swollen mitochondria, vacuolar degeneration, crista-fragmentation, concentrated karyotin, roughness of nuclear envelopes and dilated perinuclear space were observed ( ×15 000).