根田鼠粪便皮质酮的检测效能

为验证根田鼠粪便皮质酮的可检测效能,本研究检测根田鼠粪便皮质酮含量的昼夜变化,并检测急性应激后和慢性应激期间根田鼠粪便皮质酮含量变化,及其慢性应激个体的HPA 轴负反馈功能。结果表明,根田鼠粪便皮质酮水平具有明显的似昼夜节律,粪便中皮质酮含量的最高点出现在08:00 和24:00,最低点在12:00 和16:00;在终止急性应激12 h 后,根田鼠粪便皮质酮含量显著增加,且有性别间差异;慢性应激根田鼠粪便皮质酮含量始终保持在高水平;再次急性应激,慢性应激根田鼠个体的粪便皮质酮含量较对照个体升高的时间延后。上述结果说明,根田鼠的粪便皮质酮含量能够反映机体所处的生理状态及应激水平,因此,该方法可用于野外根田鼠种群的相关研究并具有可靠性。     

慢性应激不同方式对大鼠血清皮质酮的影响

目的：比较慢性应激不同方式对生理状态大鼠血清皮质酮水平的影响,研究机体慢性应激反应的整体性适应特征。方法：采用连续4周的适宜游泳、束缚和二者复合的三种应激方式后,测定大鼠血清皮质酮基础含量,分析不同慢性应激方式对皮质酮水平的影响。结果：血清皮质酮水平与对照组比较,复合组无显著性差异;游泳组虽升高但无显著性;束缚组升高有显著性意义。结论：束缚可致大鼠血清皮质酮水平增高;初步认定游泳与束缚复合慢性应激方式可能对机体的整体适应性能具有积极意义。     

外源性皮质酮对雄性根田鼠交配行为的作用

本文研究了皮质酮对雄性根田鼠交配行为的作用。实验个体分别注射0.10 ug/ g体重、0. 60 ug / g体重和1.00 ug/ g体重剂量的皮质酮,1 h后测定每只雄性根田鼠的交配行为。结果显示,3 个处理组动物具有射精能力的个体比率及其爬跨、抽动和射精潜伏期与对照组动物相比均无显著差异,爬跨和抽动频次也无显著变化。不同处理组个体的血浆睾酮含量无显著差异。因此,皮质酮没有影响雄性根田鼠的交配行为和性激素的分泌。该结果提示,哺乳动物在急性应激条件下所分泌的皮质酮可能不参与对性行为的调控。     

小脑电刺激对家鸽乙酰胆碱酯酶活力的影响

选用成年健康家鸽,对小脑进行连续电刺激后,分别抽取家鸽外周血清及全脑测定乙酰胆碱酯酶活力变化,以探讨鸟类小脑刺激与乙酰胆碱酯酶活力变化之间的相关性.结果 表明:在刺激小脑皮层后,家鸽外周血清中乙酰胆碱酯酶活力显著上升(P＜0.05);而在刺激小脑皮层后,脑组织中乙酰胆碱酯酶活力显著降低(P＜0.05).推测电刺激引起外周组织乙酰胆碱释放,从而引起肌肉强直,血清中胆碱酯酶的活力升高.而电刺激小脑使抑制性神经元功能兴奋,脑中胆碱能神经元功能减弱,乙酰胆碱的释放减少,脑组织中胆碱酯酶的活力降低.     

变压器噪声暴露对豚鼠应激、肝肾及免疫功能的影响

目的:探讨短时间内变压器噪声暴露对豚鼠应激、肝肾及免疫功能的影响。方法:取32只健康成年(5-6月龄)豚鼠随机分为实验组和对照组,每组16只。实验组给予录制的变压器噪声(声压级范围40.8-55 d B SPL,频谱范围150-2000 Hz)连续暴露28天,10小时/天(晚10点到早上8点),对照组在相同条件下饲养,无噪声暴露。噪声暴露结束后,对实验豚鼠的应激、肝肾及免疫功能进行定量评估比较。结果:噪声暴露28天后实验组豚鼠的应激状态指标(ACTH、血清皮质醇)与对照组比较差异无统计学意义(P0.05),主要肝肾功能指标与对照组比较差异无统计学意义(P0.05),免疫相关指标(Ig G、Ig A、Ig E、IL-1、IL-2)比较差异无统计学意义(P0.05)。结论:声压级范围为40.8-55 d B SPL、频谱范围为150~2000 Hz的变压器噪声连续暴露28天(10小时/天)对成年豚鼠应激、肝肾及免疫功能无明显影响。     

慢性低氧对雄性大鼠血浆皮质酮及睾酮水平的影响

目的:研究低氧对雄性大鼠性腺及相关激素水平的影响。方法:分别检测3km、5km及杭州海拔水平雄性大鼠睾丸和附睾指数、血浆皮质酮和睾酮水平。结果:3km组体重、睾酮含量均显著下降,睾丸指数、血浆皮质酮显著上升;5km组体重、附睾指数和睾酮含量均显著下降,皮质酮含量显著上升。结论:慢性低氧能显著影响雄性成年大鼠性腺及血浆睾酮水平,该结果显示哺乳动物在慢性低氧条件下生殖内分泌功能呈现抑制状态。     

噪声暴露对血中微量元素锌,铜的影响

噪声暴露对机体正常牛理机能的损害已日益被人们重视。我们曾报道噪声暴露对学习机能有严重的影响,并探讨了其作用机制。至于噪声暴露对血中微量元素的影响,国内外报道甚少。本工作对此进行探讨,这在理论上和应用上无疑都具有一定意义。     

变压器噪声暴露对SD大鼠听力及应激状态的影响研究

目的:探究短时间内低声级强度低频的变压器噪声暴露对SD大鼠听力及应激状态方面的影响。方法:选取90只SPF级健康无听力障碍的(雌雄各半)SD大鼠作为实验对象,随机分为实验A、B组和对照C组,A、B组分别给予声级上限为65 dB SPL、60 dB SPL(频谱范围:100~800 Hz)的变压器噪声,噪声暴露时程为8周,每日噪声给予时间为22点至次日8点,C组在相同条件下饲养,不给予噪声暴露。噪声暴露结束后,通过DPOAE(畸变耳声发射)、ABR(听性脑干反应)检测、耳蜗铺片及毛细胞计数对SD大鼠听力学状况进行评估;通过血清中促肾上腺皮质激素(ACTH)、血清皮质醇(CORT)对SD大鼠的应激状态进行评估。结果:在变压器噪声暴露的8周内,各组大鼠生长状况良好,体重均呈正常生理性增长,组间无明显差异(P0.05);在变压器噪声暴露8周后,对A、B、C三组大鼠的听力学指标进行两两比较,组间均无明显差异(P0.05),对大鼠血清中促肾上腺皮质激素(ACTH)、血清皮质醇(CORT)的含量进行三组间比较,组间差异均无统计学意义(P0.05)。结论:连续暴露于声压级上限65/60 dB SPL,频谱范围为100~800 Hz的变压器噪声下8周(10小时/天)对SD大鼠听力未产生明显影响,未引发SD大鼠应激状态。     

皮质酮对大鼠再生肝细胞鸟氨酸脱羧酶活性及其基因表达的影响

采用高效液相色谱和原位杂交技术研究了皮质酮对大鼠再生肝细胞鸟氨酸脱羧酶 (ODC)活性及ODCmRNA表达的影响。结果显示 ,大鼠完整肝脏中ODC水平较低 ,2 / 3肝切除 (PH)后 3h ,不同处理组ODC活性开始升高 ,6h达到最高值 ,其中 ,去肾上腺 NaCl组和糖皮质激素受体拮抗剂RU4 86处理组的酶活性高于对照组 (去肾上腺假手术组 ) ,而去肾上腺 皮质酮处理组的酶活性低于对照组 ,36h恢复到肝切除前水平 ;完整肝脏的ODCmRNA水平极低 ,PH后表达量迅速增加 ,5h达到最大值 ,不同处理组mRNA水平的高低顺序与酶活性一致 ,12h降至肝切除前水平 ;在PH前 12h给大鼠注射RU4 86 (10mg/kg体重 ) ,取得了与去肾上腺 NaCl处理鼠相似的结果。以上结果表明 ,在PH诱导的再生肝细胞中 ,ODCmRNA表达量的增加和 /或减少是造成ODC活性改变的原因之一 ,皮质酮对ODC活性及其mRNA的表达具有抑制作用 ,主要表现在肝再生的早期 ,该作用可能是通过受体实现的     

鸟类应激反应的诱发和影响因素

应激反应是动物应对环境变化或社会压力的重要机制,表现为下丘脑-垂体-肾上腺轴(HPA轴)被激活并产生糖皮质激素。鸟类的糖皮质激素主要是皮质酮。通过检测鸟类体内的皮质酮水平,可以了解鸟类的应激状态水平,进而了解诱发和影响鸟类应激反应的因素,这有助于理解鸟类如何适应环境、如何权衡生活史各阶段的能量分配等。而通过长期监测动物个体的生存和应激状况,对濒危鸟类的保育工作也具有重要参考价值。本文综述了诱发鸟类应激反应的因素,包括天气、捕食压力、食物可获得性、人为干扰和城市化以及社会压力等。归纳出影响鸟类应激反应程度的主要因素,包括光周期、生境、性别、年龄、社会等级和早期经历等8个方面。提出了应激反应在个性、认知、系统发育等领域的应用,以及慢性应激、羽毛皮质酮检测等值得关注的内容。     

噪声和高温对机体健康影响的复合效应

当今社会随着经济和科技的发展,多种有害职业因素往往共同存在于同一岗位。复合因素对机体健康影响的相互作用包括四种情况:协同作用、相加作用、拮抗作用和无关作用。噪声和高温作为有害的职业因素常存在于同一岗位,那么噪声复合高温对机体健康会产生怎样的影响,这两种环境因素是否存在复合效应?文献报道不一。噪声和高温联合对听觉系统、心血管系统、神经系统的影响可能表现为协同、相加、拮抗和无关作用,对呼吸系统的影响表现为拮抗作用,目前,研究结果不一致主要原因是实验条件和暴露方法的不一致。我们认为将来的研究热点集中在噪声和高温联合产生复合效应的条件及剂量反应关系研究、机制及防治措施研究,噪声和高温联合对其他系统如消化、免疫系统是否存在复合效应也值得深入研究。     

Stress-Related Changes in Cerebral Catecholamine and Indoleamine Metabolism: Lack of Effect of Adrenalectomy and Corticosterone

The concentrations of catecholamine and indoleamine metabolites were measured in intact and adrenalectomized mice to determine whether adrenal hormones mediate or modulate the stress-induced responses. Thirty minutes of footshock resulted in significant increases of the ratios of the dopamine (DA) catabolite, dihydroxyphenylacetic acid (DOPAC), to DA in prefrontal cortex, nucleus accumbens, striatum, hypothalamus, and brainstem, and of homovanillic (HVA)/DA ratios in nucleus accumbens, striatum, amygdala, and hypothalamus. Ratios of 3-methoxy-4-hydroxyphenylethyleneglycol to norepinephrine (NE) were also increased in prefrontal cortex, nucleus accumbens, septum, amygdala, hypothalamus, hippocampus, and brainstem. The concentration of NE was decreased in amygdala. 5-Hydroxyindoleacetic acid (5-HIAA)/5-hydroxytryptamine (5-HT, serotonin) ratios and free tryptophan were also increased in every brain region. Very similar data were obtained from mice restrained for 30 min. Adrenalectomy resulted in increased HVA/DA ratios in prefrontal cortex and striatum, and 5-HIAA/5-HT in septum. The stress-related changes were largely similar in adrenalectomized mice. Significant interactions between adrenalectomy and footshock treatment occurred in prefrontal cortical DOPAC/DA and hypothalamic NE which was depleted only in adrenalectomized mice, suggesting tendencies for these measures to be more responsive in adrenalectomized mice. Corticosterone administration (0.5-2.0 mg/kg s.c.) which resulted in plasma concentrations in the physiological range did not alter the concentrations of the cerebral metabolites measured in any region. We conclude that adrenal hormones do not mediate cerebral catecholamine or indoleamine metabolism in stress, although adrenalectomy may affect HVA and 5-HIAA metabolism, and there was a tendency for catecholamines to be more sensitive to stress in adrenalectomized animals.     

维生素C多聚磷酸酯对小鼠生长、淋巴细胞转化以及血清皮质酮含量的影响

目的探讨维生素C多聚磷酸酯对小鼠生长、淋巴细胞转化及血清皮质酮含量的影响以及淋巴细胞转化和血清皮质酮含量在热应激条件下的变化。方法在4组小鼠的饲料中依次添加35%的维生素C多聚磷酸酯,添加剂量分别为0(对照组)、500(实验Ⅰ组)、2500(实验Ⅱ组)和5000mg/kg(实验Ⅲ组),在(21±1)℃下饲养4周,对照组和实验Ⅱ组各取一半小鼠经(35±1)℃热应激处理24h。用特定生长率的方法测定小鼠的生长,用噻唑蓝还原法测定淋巴细胞转化,用荧光法测定血清中皮质酮的含量。结果各组间ICR小鼠的生长、淋巴细胞转化无明显差异;实验Ⅱ组的血清皮质酮含量明显低于对照组,其他组间差异无显著性。热应激后,淋巴细胞转化无明显变化;血清皮质酮含量较应激前有显著上升,但实验Ⅱ组仍显著低于对照组。结论在饲料中添加维生素C多聚磷酸酯对小鼠的特定生长率和淋巴细胞转化均无显著影响,但会降低小鼠血清皮质酮的含量。     

大鼠胎儿期噪声暴露对成年后听觉目标探索行为的影响

环境噪声被认为是影响健康的重要因素之一,但有关胎儿期环境噪声对成年后听觉行为的影响缺少系统的研究。本研究对胎儿噪声暴露组、成年噪声暴露组和正常对照组大鼠在出生后第11周开始进行为期17d的听觉目标探索训练,观察其在水迷宫中寻找听觉目标的行为差异。以大鼠寻找平台的时间、成功率、运动轨迹为指标对其听觉目标探索行为进行比较。结果发现,噪声暴露可导致大鼠在水迷宫中的听觉目标探索行为的缺陷,在胎儿期噪声暴露比成年期噪声暴露对动物探索听觉目标的行为影响更大。该结果提示,孕期进行适当的噪声防护以保证优生优育是非常必要的。     

Effects of corticosterone and 2,3,7,8‐tetrachloro‐ dibenzo‐p‐dioxin on epididymal antioxidant system in adult rats

2,3,7,8‐Tetrachlorodibenzo‐p‐dioxin (TCDD), an endocrine disruptor, causes epididymal toxicity by inducing oxidative stress. Glucocorticoids have been found to influence TCDD action in vitro and in vivo. The present experiments were set up to analyze the effects of TCDD on rat epididymal antioxidant system under the influence of increased corticosterone level. Adult male Wistar/NIN rats (70–80 days old) numbering 24 (six per group) were used in the study. Corticosterone (3 mg/kg body weight per day) or TCDD (100 ng/kg body weight per day) were administered or coadministered to rats for 15 days. Treatment with corticosterone or TCDD decreased the levels of serum testosterone significantly. In caput, corpus, and cauda fractions, administration of corticosterone or TCDD increased the levels of lipid peroxidation and hydrogen peroxide and decreased the activities of superoxide dismutase and catalase significantly. Coadministration of corticosterone and TCDD to rats decreased the levels of serum testosterone significantly as compared with rats treated with TCDD alone. In caput, corpus, and cauda fractions, the levels of lipid peroxidation and hydrogen peroxide were increased and activities of superoxide dismutase and catalase were decreased significantly as compared with rats treated with TCDD alone. Stress, characterized by increased glucocorticoid levels and activity, may enhance TCDD‐induced epididymal toxicity. © 2010 Wiley Periodicals, Inc. J Biochem Mol Toxicol 24:242–249, 2010; View this article online at wileyonlinelibrary.com . DOI 10.1002/jbt.20332     

等渗NaCl和KCl胁迫对高粱幼苗生长和气体交换的影响

本文比较研究了等渗ＮａＣｌ和ＫＣｌ胁迫下,高粱幼苗生长及叶片离子含量、质膜相对透性和有关气体交换参数的变化。结果表明,在低浓度ＮａＣｌ和ＫＣｌ胁迫７天时,高粱生长、含水量和质膜相对透性与对照相比没有明显变化,而净光合速率、蒸腾速率和气孔导度已明显下降,叶肉细胞间隙ＣＯ２浓度明显增加。ＮａＣｌ胁迫下叶片Ｎａ＋含量成倍增加,而Ｋ＋和Ｃａ２＋含量无明显变化。ＫＣｌ胁迫时叶片Ｋ＋含量明显增加,Ｃａ２＋含量明显下降,而Ｎａ＋含量没有明显变化。随着ＮａＣｌ或ＫＣｌ浓度的增加,幼苗生长和叶片含水量明显下降,质膜透性和细胞间隙ＣＯ２浓度明显增加,净光合速率、蒸腾速率和气孔导度进一步下降。ＮａＣｌ胁迫下叶片Ｎａ＋含量进一步增加,Ｋ＋和Ｃａ２＋进一步下降,而ＫＣｌ胁迫下叶片Ｋ＋含量进一步增加,Ｎａ＋和Ｃａ２＋含量进一步下降。ＫＣｌ对高粱生长抑制、质膜透性、Ｃａ２＋含量下降及光合气体交换参数的影响均明显大于等渗的ＮａＣｌ。     

Effects of housing condition and early corticosterone treatment on learned features of song in adult male zebra finches

Early developmental stress can have long-term physiological and behavioral effects on an animal. Developmental stress and early corticosterone (Cort) exposure affect song quality in many songbirds. Early housing condition can act as a stressor and affect the growth of nestlings and adult song, and improvements in housing condition can reverse adverse effects of early stress exposure in rodents. However, little is known about this effect in songbirds. Therefore, we took a novel approach to investigate if housing condition can modify the effects of early Cort exposure on adult song in male zebra finches. We manipulated early housing conditions to include breeding in large communal flight cages (FC; standard housing condition; with mixed-sex and mix-aged birds) versus individual breeding cages (IBC, one male–female pair with small, IBC-S, or large clutches, IBC-L) in post-hatch Cort treated male birds. We found that Cort treated birds from IBC-S have higher overall song learning scores (between tutor and pupil) than from FC but there is no difference between these groups in the No-Cort treated birds. When examining the effects of Cort within each housing condition, overall song learning scores decreased in Cort treated birds from flight cages but increased in birds from IBC-S compared to controls. Likewise, the total number of syllables and syllable types increased significantly in Cort treated birds from IBC-S, but decreased in FC-reared birds though this effect was not statistically significant. These findings suggest that the effects of early Cort treatment on learned features of song depend on housing condition.