Linkage of stress-induced hypocalcemia, gastric lesions, and emotional behavior in Wistar-Kyoto rats.

The effects of water-restraint stress on blood calcium levels and gastric pathology and their behavioral relevance were examined in Wistar-Kyoto (WKY) and Wistar rats. The stress induced more severe hypocalcemia (0.32 mM decrease) and gastric lesions (34.6 mm in mean length) in WKY rats than in Wistar rats (0.19 mM and 17.7 mm, respectively). The magnitude of hypocalcemia correlated positively with that of gastric lesions in both strains (WKY, r = 0.59; Wistar, r = 0.69). In the forced-swimming test, WKY rats exhibited a longer immobility time (6.53 min) and a shorter struggling time (0.54 min) than Wistar rats (3.33 and 1.90 min, respectively). The severity of hypocalcemia and gastric lesions correlated positively (r = 0.59 and 0.69, respectively) with the length of immobility time in the WKY rats, while it correlated negatively (r = -0.70 and -0.61, respectively) with the length of struggling time in the Wistar rats. These results suggest that stress-induced hypocalcemia and gastric lesions are closely related and are also influenced by behavioral responsiveness in a strain-dependent manner.