催产素对于应激孕鼠母性攻击行为的影响及其机制的探究

Effect and mechanism of oxytocin on maternal aggression in stress model rats during pregnancy period

目的观察不同剂量催产素对应激孕鼠母性攻击行为的影响以探讨其保护性作用机制。方法将40只Wistar孕鼠随机分为低、中、高剂量催产素组和生理盐水组,每组各10只,待孕期第14天至分娩日给予强迫游泳实验,每日1次,其中低、中、高剂量催产素组每次应激前于腹腔分别给予0.3、1.0、2.0mg/kg催产素(均稀释成1mL的溶液);生理盐水组应激前给予等体积生理盐水。并于分娩后第3天进行攻击行为观察,比较各组行为指标如撕咬次数、攀压次数、攻击次数、攻击持续时间、攻击潜伏期等的差异。之后分别用HE染色和免疫组织化学法检测大鼠视上核、室旁核催产素神经元核团损伤变化以及催产素表达状况。结果在撕咬次数方面,中、高剂量催产素组均明显高于生理盐水组,差异有统计学意义(P<0.01);攻击总数方面,高剂量催产素组高于生理盐水组,差异有统计学意义(P<0.05);攻击持续时间方面,中、高剂量催产素组低于生理盐水组,差异有统计学意义(P<0.05);攻击潜伏期方面,中、高剂量催产素组显著高于生理盐水组,差异有统计学意义(P<0.01)。HE染色显示,视上核中可见,4组之间在核团神经元核染、数量、密度方面比较差异有统计学意义(P<0.01);室旁核中可见,生理盐水组与高剂量催产素组在核团灰密度分布方面比较差异有统计学意义(P<0.05),低、中剂量催产素组和生理盐水组3组间差异无统计学意义(P>0.05)。免疫组织化学结果显示,视上核中低剂量催产素组与生理盐水组灰度值比较差异无统计学意义(P>0.05),高剂量催产素组与生理盐水组比较差异有统计学意义(P<0.01);室旁核中,中剂量催产素组与生理盐水组灰度值比较差异有统计学意义(P<0.01),低剂量催产素组和生理盐水组比较差异无统计学意义(P>0.05)。结论应激会明显损害孕鼠的攻击能力,使用催产素可调节应激对母性攻击行为的影响,可以调节脑部催产素神经核团的表达水平,减缓催产素神经元胞核的肿胀、溶解。

Objective To investigate the effect and protective mechanism of different‐dose of oxytocin on maternal ag‐gression in stress model rats during pregnancy period .Methods Female Wistar rats（n=40） were randomly divided into four groups named group A（n=10） ,group B（n=10） ,group C（n=10） and group D（n=10） .During the intervals from 14th day to due day groups（A ,B ,C） were intraperitoneally injected with 1 mL dilated solution of 0 .3 ,1 .0 ,2 .0 mg/kg of oxytocin respec‐tively before the forced swimming once a day ;meanwhile ,group D as control group was given equal volume of normal saline . Some indexes of maternal aggression were tested ,such as biting times ,keep‐down times ,attack times ,attack duration and la‐tent period ,on the 3rd day of parturition .HE staining and immunohistochemical method were used to test changes of oxytocin nuclei injury and oxytocin expression level .Results Regarding biting times group B and C were significantly different from group D（P〈0 .01）;for attack times group C was different from group D（P〈0 .05）;as to attack duration group B and C were different from group D （P〈0 .05）;for attack latent period group B and group C were significantly different from group D（P〈0 .01） .HE staining showed that in supraoptic nuclei（SON） the four groups were significantly different in staining ,numbers and density（P〈0 .01）;in paraventricular nuclei（PVN） ,group C was different from group D（P〈0 .05） ,while there was nonbsp;difference in group A ,B and D（P〉0 .05） .Immunohistochemical method showed in SON gray density there was no difference in both group A and D（P〉0 .05）;group C was significantly different from group D（P〈0 .01）;in PVN gray density ,group B was significantly different from group D （P〈 0 .01） ,while there was no difference in group A and D （P〉0 .05） . Conclusion Stress would obviously impair maternal aggression of pregnant rats;different doses of oxytocin could regulate such behavior as influenced by stress and meditate rat brain nuclei oxytocin expression level so that swelling and dissolution of nuclei could be attenuated .