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【摘要】 目的 觀察腎上腺素能受體拮抗劑普萘洛爾和哌唑嗪對慢性輕度不可預知應激模型(CUMS)大鼠行為學及急應激暴露后血清皮質酮水平(CORT)、中樞海馬誘導型一氧化氮合酶(iNOS)表達的影響，探討其應激保護作用。方法 健康成年Wistar雄性大鼠32只，隨機分為4組：空白對照組、CUMS組、普萘洛爾組和哌唑嗪組。CUMS造模前后，用曠場實驗測各組大鼠的行為學變化。造模結束后，應激動物接受1.0?mA，5?s，持續(xù)60次的急性電擊刺激，2?h?后斷頭處死。放射免疫分析法測大鼠血清皮質醇含量換算成皮質酮含量;Western blot測中樞海馬中iNOS表達量。結果 與對照組比較，普萘洛爾組大鼠水平運動得分、豎立次數和修飾次數減少(P<0.05)，中樞海馬iNOS表達量明顯增加(P<0.01);哌唑嗪組大鼠與對照組比較無明顯差異，血清CORT水平明顯高于普萘洛爾組(P<0.05)。結論 哌唑嗪可明顯改善CUMS模型大鼠的行為學改變，有利于應激個體再次遭遇急性應激時CORT的調動，減輕應激導致中樞海馬損傷的程度。普萘洛爾可緩解應激時的焦慮水平，但不能扭轉應激對中樞海馬的損傷。
【關鍵詞】 慢性輕度不可預知應激;應激;皮質酮;一氧化氮合酶;大鼠，Wistar醫(yī).學.全.在.線m.zxtf.net.cn
YANG Lejin, LIU Xin, JIANG Hong, FAN Shujuan, LU Yanxia, LIU Meng, PAN Fang
(Department of Medical Psychology, School of Medicine, Shandong University, Jinan 250012, China)
To explore the effects of adrenoceptor antagonists, propranolol and prasozin on chronic unpredictable mild stress (CUMS) rats, serum corticosterone (CORT)level and hippocampal inducible nitric oxide synthase level(iNOS) following acute stress. Methods Thirtytwo Wistar male rats were randomly divided into four groups： the control group, the CUMS group, the propranolol group and the prasozin group. The behavior of all rats was determined in an openfield test before and after CUMS. Animals were sacrificed by decapitation 2h after an acute stress of 1.0?mA, 5?s, persisting 60 times. The content of serum CORT was evaluated by cortisol RIA, and iNOS was measured by western blot. Results Compared with the controls, the propranolol group exhibited a decreased square crossing number, rearing score and grooming number(P<0.05) and an increased iNOS level in the hippocampus(P<0.01). There was no statistical difference between the prasozin group and the control group. Serum corticosterone of the prasozin group was higher than that of the propranolol group(P<0.05). Conclusions Prasozin could improve the behavior of CUMS rats and upregulates the CORT level after exposure to acute stress, it also reverses impairment of the hippocampus produced by stress. Although propranolol could alleviate anxiety in stress, it could not reverse the impairment of the hippocampus produced by stress.
Key words: Chronic unpredictable mild stress; Stress; Corticosterone; Nitric oxide synthase; Rats, Wistar
