The effects of mild stress to gastrointestinal motility and oxytocin in hypothalamic paraventricular nucleus of rats / 中华行为医学与脑科学杂志

ABSTRACT

Objective To study the changes of gastrointestinal movement function in rats with chronic unpredictable mild stress(CUMS) and explore the mechanisms underlying it.Methods The rats were divided into stress model group and control group.The stress model rats were induced by 21-day chronic unpredictable mild stress as well as social-isolated fed.The rate of ink propulsion of gastrointestinal tract and the contraction of intestinal canal in rats were observed.Immunohistochemistry was adopted to detect the expression of OT in rats.Results (1) After the models were induced,weight-gain and sucrose preference of model group ((69.97 ± 9.81) g,(49.05± 5.98) g) were lower than those in control group ((116.27 ± 13.60) g,(83.51 ± 3.08) g) (P ＜ 0.001),and both the crossing-score and rearing-score ((24.00 ± 13.52),(3.90 ± 2.51)) were lower than those in control group ((53.60 ± 27.98),(11.50 ± 8.85)) in the open-field test.(2) The rate of ink propulsion of model group ((67.33 ± 6.24) ％) was decreased when compared to the control group ((76.83 ± 10.00) ％) (P ＜ 0.05),and the intestinal canal contraction amplitude and contraction frequency ((1.37 ± 0.18) g,(0.58 ± 0.02) S-1) were lower than those in control group ((1.88 ± 0.13) g),(0.62 ± 0.04) S-1) (P ＜ 0.05).(3) Compared with the control group (6.07 ± 3.71),OT immunoreactive substance was increased in model group (59.17 ± 16.08) of rats (P＜0.001).Conclusion Chronic stress can cause the decrease in gastrointestinal movement function of rats.These changes may be related to the increased expression of OT in paraventricular nucleus.