There is a gender-related comorbidity of
pain-related and
inflammatory bowel diseases with
psychiatric diseases. Since the impact of experimental gastrointestinal
inflammation on the emotional-affective behavior is little known, we examined whether experimental
gastritis modifies anxiety, stress coping and circulating
corticosterone in male and female Him:OF1 mice.
Gastritis was induced by adding
iodoacetamide (0.1%) to the
drinking water for at least 7 days.
Inflammation was assessed by gastric histology and
myeloperoxidase activity, circulating
corticosterone determined by
enzyme immunoassay, anxiety-related behavior evaluated with the elevated plus maze and stress-
induced hyperthermia tests, and depression-like behavior estimated with the tail suspension test.
Iodoacetamide-induced
gastritis was associated with gastric mucosal surface damage and an increase in gastric
myeloperoxidase activity, this increase being significantly larger in female mice than in male mice. The rectal temperature of male mice treated with
iodoacetamide was enhanced, whereas that of female mice was diminished. The circulating levels of
corticosterone were reduced by 65% in female mice treated with
iodoacetamide but did not significantly change in male mice. On the behavioral level,
iodoacetamide treatment caused a decrease in nocturnal home-cage activity, drinking and feeding. While depression-related behavior remained unaltered following induction of
gastritis, behavioral indices of anxiety were significantly enhanced in female but not male mice. There was no correlation between the estrous cycle and anxiety as well as circulating
corticosterone. Radiotracer experiments revealed that
iodoacetamide did not readily enter the brain, the blood-brain ratio being 20:1. Collectively, these data show that
iodoacetamide treatment causes
gastritis in a gender-related manner, its severity being significantly greater in female than in male mice. The induction of
gastritis in female mice is associated with a reduction of circulating
corticosterone and an enforcement of behavioral indices of anxiety. Gastric
inflammation thus has a distinct gender-dependent influence on emotional-affective behavior and its neuroendocrine control.