Objective: The purpose of this study was to observe the changes of c-Fos protein expression in supraoptic nucleus (SO) and paraventricular nuclei (PVN) to investigate the dysfunction mechanism in blood, osmotic pressure and thermoregulation of climacteric period following different ambient temperature stimulation to ovariectomized rats. Methods: Rats of ovariectomy group(OVX group) and Sham operation group(Sham group) were placed in incubators at 4 ℃, 10 ℃, 25 ℃, 33 ℃ and 38 ℃ for 2 hours respectively, and then remove their brains after anesthesia. c-Fos expression was detected by immunohistochemical method. Results: Comparison of c-Fos protein expression- positive cell densities in OVX and Sham groups under the same temperature: SO has markedly low strong positive cell densities under 4 ℃, 10 ℃ and 38 ℃; PVN has low strong positive cell densities under 4 ℃, 10 ℃, 33 ℃ and 38 ℃. The c-Fos protein expression-positive cell densities in SO and in PVN of Sham group and OVX group under different temperatures share the same change rule, i.e. below 25 ℃ the cell densities decrease as the temperature rises, while above 25 ℃ they increase as the temperature rises. Under different temperatures,the strong positive cell densities of Sham group in SO and PVN are significantly different between adjacent temperatures;the strong positive cell densities of OVX group in SO share the same rules,except between 4 ℃ and 10 ℃ and between 33 ℃ and 38 ℃ ;while OVX group in PVN have difference only between 25 ℃and 33 ℃. Conclusions: Under the same temperature stimuli, the expression of c-Fos protein of different groups in SO and in PVN differs. Under different temperature stimuli, the range of excitatory neurons in SO and in PVN narrows and the densities decrease, which may possibly resulting in abnormalities of blood and osmotic pressure and thermoregulation and further leading to a series of climacteric symptoms such as dizziness, fluctuation of blood pressure and hot flashes.%目的:以不同温度刺激去卵巢大鼠,观察下丘脑视上核(SO)和室旁核(PVN)细胞c-Fos蛋白表达的变化,探讨更年期妇女血压、渗透压以及体温调节功能异常的可能机制.方法:将去卵巢(OVX)和假手术(Sham)大鼠分别置于4,10,25,33和38℃5个温度等级的培养箱内,2 h后取脑.采用免疫组织化学法检测各实验组SO和PVN的c-Fos蛋白的表达.结果:同一温度刺激后,SO表达c-Fos蛋白强阳性细胞的密度4,10和38℃时OVX组较Sham组明显低.PVN表达c-Fos强阳性细胞的密度4,10,33和38℃时较Sham组低.不同温度刺激下,OVX组与Sham组SO和PVN表达c-Fos蛋白阳性细胞的密度变化规律相似:低于25℃时,细胞密度随着温度升高而减小;高于25℃时,随着刺激温度升高而增大.不同温度刺激下,Sham组表达c-Fos蛋白强阳性细胞的密度SO和PVN相邻温度之间差异均有统计学意义;OVX组SO除了4℃与10℃、33℃与38℃外,其他各相邻温度组间差异均有统计学意义.OVX组PVN只有25℃与33℃之间差异有统计学意义.结论:同一温度刺激下,实验组SO和PVN细胞c-Fos蛋白表达不同;不同温度刺激下,SO和PVN对外界温度刺激的敏感范围缩小,敏感细胞密度降低.以上变化可能引起机体血压、渗透压以及体温调节异常,出现头晕、血压不稳和潮热等一系列更年期相关症状.
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