鱼类生长和生长激素分泌活动的调节（综述）

本文综述近十年来在鱼类生长激素分泌和鱼体生长的神经内分泌调节方面取得的研究进展,阐明脑（各种神经内分泌因子）－脑垂体（分泌生长激素）－肝脏（产生类胰岛素生长因子）轴调控鱼类生长的作用,并在此理论基础上提出可供养鱼生产实践应用的基本途径。     

EFFECTS OF DOWNHILL AND UPHILL EXERCISES OF EQUIVALENT SUBMAXIMAL INTENSITIES ON SELECTED BLOOD CYTOKINE LEVELS AND BLOOD CREATINE KINASE ACTIVITY

The study was aimed at comparing the effects of concentric (CONC) and eccentric (ECC) exercises of equivalent (in terms of relative work load expressed as a percentage of VO₂max) moderate intensity on selected blood cytokine levels and blood creatine kinase (CK) activity. Twenty recreationally active healthy young male volunteers were randomized between two groups that performed a single 1 h bout of CONC (uphill running) or ECC (downhill running) exercise at 60% of the respective individual VO₂max. Venous blood taken 1 h before, at the end, and 24 h after the exercise was processed for plasma and analyzed for CK activity and IL-6, IL-1β and TNFα levels. There was no between-group difference in these cytokines prior to or just after the exercise, and in pre-exercise CK activity. The cytokines elevated significantly and similarly in both groups during the exercise, with no significant change in CK activity. Twenty-four hours later, CK activity and IL-6 were at pre-exercise levels in the CONC group, but showed further major increases in the ECC group, resulting in marked between-group differences in these indices. Changes in IL-1β and TNFα levels during the recovery period showed only minor differences between the study groups and produced no significant between-group difference in these cytokines. However, IL-1β level normalized in the ECC but not in the CONC group. The study suggests that moderate intensity ECC exercise compared to CONC exercise of equivalent relative work load results in considerably greater muscle damage and its related elevation in circulating IL-6, but it does not cause a major systemic inflammatory response.     

黄颡鱼重组生长激素的制备及对其鱼苗生长的影响

生长激素在渔业生产中具有重要的应用价值, 通过制备黄颡鱼(Pelteobagrus fulvidraco)同源重组生长激素并用于促生长实验, 从而为建立鱼苗快速培育方法提供理论依据。根据已知黄颡鱼生长激素(PfGH)基因cDNA序列, 利用IPTG诱导和SDS-PAGE分析方法, Western印迹表明在IPTG终浓度1.0 mmol/L、温度17℃和培养时间14h的条件下, 黄颡鱼生长激素基因在大肠杆菌中大量表达, 获得重组生长激素蛋白。然后, 随机选取黄颡鱼分为4组放入室内水族箱中进行养殖, 每箱35尾, 体质量为(0.850.01) g, 每组设3个平行, 水体循环净化。用制备的重组生长激素浓度分别为0、1、5和10 mg/L对黄颡鱼进行浸泡处理, 每周一次, 0为对照组。在养殖4周后, 对各组增重率和特定生长率进行比较, 结果表明1 mg/L组增重率和特定生长率分别比对照组提高了29.67% (P0.05)和11.90% (P0.05), 5 mg/L组增重率和特定生长率分别比对照组提高了21.32% (P0.05)和8.83% (P0.05), 各组间体成分等均无明显差异。停用生长激素4周后, 各组黄颡鱼的生长性能、体成分等均无显著差异。研究表明通过原核表达可以获得黄颡鱼重组生长激素, 用于促进鱼苗生长培育的最佳浸泡浓度为1 mg/L。       

EFFECTS OF AEROBIC EXERCISE ON THE CIRCADIAN RHYTHM OF HEART RATE AND BLOOD PRESSURE

Although the effects of aerobic exercise on resting heart rate, heart rate variability, and blood pressure have been investigated, there are scant data on the effects of aerobic exercise on the circadian rhythm of such cardiovascular parameters. In this study, we investigated the effects of aerobic exercise on the 24?h rhythm of heart rate and ambulatory blood pressure in the morning, when cardiovascular events are more common. Thirty-five healthy young subjects were randomized to control and aerobic exercise groups. Subjects in the latter group participated in their respective exercise program for two months, while those in the former group did not exercise. Twenty-four-hour electrocardiogram and ambulatory blood pressure monitoring data were obtained at baseline and at the end of the exercise intervention. The control group showed no changes, while the aerobic exercise group showed a significant decrease in heart rate (73.7?±?6.6?bpm to 69.5?±?5.1?bpm, p?<?0.005) and sympathetic activity such as LF/HF ratio (2.0?±?0.7 to 1.8?±?0.6, p?<?0.05) throughout the 24?h period, particularly in the daytime. The decrease in the heart rate was most prominent in the morning. However, heart rate and LF/HF ratio showed no statistical changes during the night. No significant changes were observed in blood pressure. These findings suggest aerobic exercise exerts beneficial effects on the circadian rhythm of heart rate, especially in the morning. (Author correspondence: hshio@kobe-u.ac.jp)     

促黄体素释放激素类似物和多巴胺对鲤鱼幼鱼和性成熟雌鱼生长激素分泌的作用

以性腺未发育的５～６月龄幼鲤和１龄性成熟雌鲤为材料,研究年龄对促黄体素释放激素类似物和多巴胺能药物刺激的鲤鱼ＧＨ分泌的影响。结果表明：５～６月龄幼鱼血清基础ＧＨ水平明显低于１龄性成熟鱼;５～６月龄幼鱼对ＬＨＲＨＡ、ＤＡ和ＡＰＯ刺激的ＧＨ分泌的反应性也明显低于１龄性成熟鱼;ＤＡ和ＡＰＯ在５～６月龄幼鱼和１龄性成熟鱼都不能增强ＬＨＲＨＡ对ＧＨ分泌的刺激作用;ＤＯＭ不影响５～６月龄幼鱼和１龄性成熟鱼的血清ＧＨ水平。     

不同的下丘脑肽和神经递质对鲤鱼促性腺激素和生长激素分泌活动的影响

以１龄性腺发育中期鲤鱼为材料,采用腹腔（ｉ．ｐ）注射的方法,研究不同的下丘脑肽和神经递质对鲤鱼促性腺激素（ＧｔＨ）和生长激素（ＧＨ）分泌的影响。结果表明：促甲状腺激素释放激素（ＴＲＨ）、Ｌ－多巴（Ｌ－ＤＯＰＡ）、甲基睾酮（ＭＴ）、γ－氨基丁酸（ＧＡＢＡ）、促黄体素释放激素类似物（ＬＨＲＨ－Ａ）和三碘甲状腺原氨酸（Ｔ３）都能显著刺激ＧｔＨ的分泌,但最大效应时间各不相同。ＴＲＨ和ＬＨＲＨ－Ａ能促进ＧＨ的分泌,Ｌ－ＤＯＰＡ、ＭＴ、ＧＡＢＡ对血清ＧＨ水平没有明显影响;Ｔ３则对ＧＨ分泌有一定的抑制作用。这说明鲤鱼ＧｔＨ和ＧＨ的分泌除了受各自的下丘脑释放因子和释放抑制因子的双重神经内分泌调控外,还受多种其它相同和不同调节因子的影响,也反映了鲤鱼ＧｔＨ和ＧＨ分泌的神经内分泌调控的复杂性。     

儿茶酚胺类药物对草鱼生长激素分泌的影响

本文研究了儿茶酚胺类药物对草鱼生长激素水平的影响。腹腔注射儿茶酚胺合成抑制剂α－甲基－对－酪氨酸（α－ＭＰＴ,５μｇ／ｇｂ·ｗ和５０μｇ／ｇｂ·ｗ）显著降低草鱼鱼种血清生长激素水平,腹腔注射儿茶酚胺能神经毒素６－羟多巴胺（６－ＨＯＤＡ,５μｇ／ｇｂ·ｗ和５０μｇ／ｇｂ·ｗ）也显著降低草鱼鱼种血清生长激素水平。阿卟吗啡（ＡＰＯ,７．１ｍｇ／Ｋｇｂ·ｗ和１２．５ｍｇ／Ｋｇｂ·ｗ）通过背大动脉插管注入草     

侧脑室注射促甲状腺激素释放激素对大鼠睡眠—觉醒的影响

采用多导睡眠描记术研究了例脑室注射促甲状腺激素释放激素(TRH)对正常大鼠和去甲状腺大鼠睡眠-觉醒的影响。在正常大鼠,TRH引起觉醒增加,浅慢波睡眠(SWS_1)、深慢波睡眠(SWS_2)和总睡眠时间(TST)均减少,异相睡眠(PS)消失,SWS_1、SWS_2和PS的潜伏期均显著延长,给药后立即产生效应并在1h内达高峰。去甲状腺对大鼠的睡眠-觉醒无明显影响,注射TRH后引起的效应与正常大鼠相似。结果提示TRH有促进大鼠觉醒的作用,对各睡眠时相均有抑制作用,其作用部位可能在下丘脑以外的中枢结构。     

日粮添加塞曼特罗（CIM）对大鼠生长胴体组成及GH水平的影响

选用２４只２月龄ＳＤ处女鼠配对分组,实验组日粮添加１０μｇ／ｇ塞曼特罗（ＣＩＭ）,试验期３０天。与对照组比较,ＣＩＭ显著提高大鼠生长速度（２７．３０％,Ｐ＜０．０１）和胴体比率,降低腰胁部脂肪重,提高腓肠肌、比目鱼肌和趾浅屈肌的鲜重和ＲＮＡ合量及ＰＮＡ／ＤＮＡ值,同时提高大鼠垂体和血清ＧＨ水平分别达３６．７０％（Ｐ＜０．０１）和２３．７７％（Ｐ＜０．０５）,降低血清脲氮含量。表明ＣＩＭ可显著促进大鼠生长,降低体脂含量,促进肌肉肥大,促进蛋白沉积。其作用机理可能还与其促进ＧＨ的合成和分泌有关。     

急性力竭运动对大鼠胃肠传输速率及回肠肌间神经丛氮能神经的影响

目的：研究力竭运动对大鼠胃肠动力的影响及其肠神经机制。方法：24只大鼠随机分成对照组和急性力竭运动组,建立力竭运动大鼠模型,测定胃肠传输速率,用酶组织化学方法和计算机图像分析技术对两组大鼠回肠肌间神经丛内氮能神经元的数目和一氧化氮合酶（NOS）的表达进行测定。结果：急性力竭运动组大鼠胃肠传输速率明显延迟,回肠肌间神经丛内氮能神经元的数目明显增多和NOS的表达显著增强（P〈0．05和P〈0．01）。结论：大鼠力竭运动后小肠肌问神经丛内氮能神经元的数目增多和NOS的表达增强可能是导致胃肠传输速率延迟的重要原因之一。     

大鼠急性运动对血清睾酮、睾丸组织丙二醛和超氧化物歧化酶的影响

本实验分别在大鼠衰竭跑后即刻、0.5、1、3及24h同时检测了血清睾酮(T)、黄体生成素、睾丸组织脂质过氧化物丙二醛和超氧化物歧化酶。结果表明,大鼠衰竭跑后恢复30min时,伴随着睾丸组织丙二醛含量的明显升高及超氧化物歧化酶活性的显著降低,血清T水平也明显降低。提示,长时间衰竭跑后血清T浓度的降低很可能与缺血-再灌引起睾丸组织氧自由基剧增及脂质过氧化损伤,从而降低了酶的活性和抑制了T的合成有关。氧自由基清除剂能减轻和预防该损伤,并能有效地防止运动后血清T的降低。     

甲状腺素对雄性去势大鼠垂体分泌LH的反应性及其在血浆中浓度的影响

本文观察了雄性去势大鼠注射T_4后对血浆和垂体组织LH含量的影响及垂体对不同剂量的LHRHa的反应性。结果表明血浆LH含量与去势对照组相比,7.5μg组的第3、6、9天明显低(P<0.05),2.5和5.0μg组各天则无差异(P>0.05)。各组对100ng/100克体重LHRHa的反应比对500ng的要大,T_4 7.5μg组对LHRHa最大反应出现的时间比2.5和5.0μg组的推迟60min。垂体重量和LH含量各组无差异(P>0.05)。结果提示:7.5μg T_4对雄性去势大鼠的LH分泌和对垂体的LHRHa反应均显示抑制作用。     

人参皂甙Rb1对大鼠心肌缺血再灌注后血管再生的影响

目的观察人参皂甙Rb1对大鼠缺血再灌注后血管再生和心肌VEGF蛋白表达的影响,并对其作用机制作初步探讨。方法结扎sD大鼠左冠状动脉前降支,将大鼠随机分为Rb1治疗组、单纯手术组及假手术组。手术2周,4周后分别测定有关心功能指标,TFC和伊文思兰染色测定梗死区、缺血区的面积比值,免疫组化方法检测心肌VEGF的表达量,Ⅷ因子和SAM染色观察微血管密度和功能血管再生情况。结果人参皂甙Rb1治疗组心功能好转,心肌微血管密度和功能血管数量明显高于单纯手术组,差异有显著统计学意义（P〈0．01）,缺血区和梗死区的范围也明显缩小,差异有统计学意义（P〈0．05）,VEGF的表达量也高于单纯手术组,差异有显著统计学意义（P〈0．01）。结论人参皂甙Rb1有促进缺血心肌血管生成、保护缺血心肌、缩小梗死面积、改善心功能的作用。     

阉割和睾丸酮替代对雄性老年大鼠下丘脑和血浆促黄体生成素释放激素水平的影响

应用放射免疫分析(RIA)技术比较了年青(2—3月龄)和老年(24—26月龄)雄性大鼠下丘脑和血浆促黄体生成素释放激素(LHRH)水平及其在睾丸切除(ORDX)和睾丸酮(T)替代下LHRH水平的变化。老年大鼠血浆T水平明显降低,下丘脑LHRH含量亦呈明显下降趋势,但血浆LHRH水平与年青大鼠十分接近。在ORDX和T替代下,两组动物血浆T水平没有明显差别,但老年大鼠下丘脑和血浆LHRH的变化率却不同程度地低于年青大鼠。上述结果提示,老年雄性大鼠下丘脑LHRH神经元系统的负反馈能力明显削弱,这也许是下丘脑-垂体-睾丸轴呈增龄性衰变的重要原因之一。     

DIFFERENTIAL EFFECTS OF PHOTOPHASE IRRADIANCE ON METABOLIC AND URINARY STRESS HORMONE CONCENTRATIONS IN BLIND AND SIGHTED RODENTS

The effects of different photophase irradiance levels on the daily rhythms of energy expenditure (DEE, calculated from oxygen consumption, VO₂) and urinary metabolites of stress hormones in sighted (Microtus socialis) and blind (Spalax ehrenbergi) rodents were compared. Five groups of each species were exposed to different irradiance levels (73, 147, 293, 366, and 498 μW/cm²) under short photoperiod (8L:16D) condition with constant ambient temperature 25?±?2°C for 21 days before assessments. As light intensity increased from 73 μW/cm², both species reduced DEE, especially among M. socialis. Cosinor analysis revealed significant ultradian rhythms in VO₂ of M. socialis with period length being inversely related to irradiance level. Conversely, in S. ehrenbergi, robust 24 h VO₂ rhythms were detected at all irradiances. In M. socialis, significant 24 h rhythms in urinary output of adrenaline were detected only at 293 μW/cm², whereas for cortisol, unambiguous rhythms were detected at 73 and 147 μW/cm². Distinct adrenaline daily rhythms of S. ehrenbergi were observed at 73 and 293 μW/cm², whereas this species exhibited significant rhythms in cortisol at 147 and 293 μW/cm². Changes in photophase irradiance levels affected stress hormone concentrations in a dose-dependent manner. There were significant negative and positive correlations of M. socialis and S. ehrenbergi stress hormones, respectively, with increasing irradiance. Our results indicate photophase light intensity is another environmental factor that can significantly affect entrainment of mammalian daily rhythms. Both low and high irradiance conditions can trigger stress responses, depending on the species' natural habitat. (Author correspondence: zubidat3@013.net.il)     

氮素对花铃期干旱再复水后棉花根系生长的影响

于2005~2006年在江苏南京农业大学卫岗试验站进行盆栽试验, 设置正常灌水(土壤含水量为田间持水量的75%左右)和棉花(Gossypium hirsutum)花铃期土壤短期干旱处理(将正常灌水的棉花自然干旱持续8 d, 以棉株出现萎蔫症状为标准, 之后复水至正常灌水水平), 每个处理再设置3个氮素水平(0、3.73、7.46 g N·pot^-1, 分别相当于0、240、480 kg N·hm^-2), 研究氮素对花铃期干旱及复水后棉花根系生长的影响。结果表明, 花铃期干旱条件下, 土壤相对含水量迅速减少, 并随氮素水平的提高而降低。在干旱处理结束时, 与正常灌水处理相比, 干旱处理棉花根重与氮素累积量显著降低, 但干物质根冠比(R/S)与氮素累积量根冠比(R_N/S_N)增大; 根系超氧化物歧化酶(SOD)和过氧化物酶(POD)活性明显升高, 而过氧化氢酶(CAT)活性降低, 同时, 丙二醛(MDA)含量相应增大。花铃期短期干旱亦显著降低棉花根系活力与叶片净光合速率。施氮可提高干旱处理棉花根重与氮素累积量, 降低SOD活性, 增强POD与CAT活性, 但以240 kg N·hm^-2水平最有利于根系生长, 其内在生理机制表现为R/S与R_N/S_N最小, 膜脂过氧化程度最低, 而根系活力最强, 其叶片的净光合速率亦最高。复水后, 干旱处理棉花根重与氮素累积量显著高于正常灌水处理; 内源保护酶活性相应变化, 其根系MDA含量与正常灌水处理已无显著差异; 根系活力显著高于正常灌水处理。施氮有助于增加复水后棉花根重与氮素累积量, 提高POD与CAT活性, 降低膜脂过氧化程度, 增强棉花根系活力, 从而提高叶片净光合速率。综合分析认为, 过量施氮或施氮不足均不利于棉花根系生长, 两年的试验结果表明, 在本试验设置的3个氮素水平中, 花铃期干旱胁迫下以240 kg N·hm^-2, 且基施50%, 初花期追施50%较适宜。     

THE EFFECTS OF EXHAUSTIVE EXERCISE ON THE ACTIVITY LEVELS OF CATALASE IN VARIOUS TISSUES OF MALE AND FEMALE RATS

The effects of exhaustive exercise on the activity levels of catalase (EC 1.11.1.6) in various tissues of male and female Sprague—Dawley rats (Rattus norvegicus) were investigated. Both the male and female rats were subdivided into an experimental group and a control group consisting of eight rats each. One group of each sex was subjected to a swimming session of 1h (experimental group) while the other group of each sex served as sedentary control groups. The tissues investigated were liver, heart, kidney and lung. The activity levels of catalase in all the tissues investigated were significantly (P< 0.05) elevated in both male and female rats as a result of exercise. The average increase in the activity levels of catalase in the various tissues investigated for both male and female rats was 417% (males 404%; females 430%). The male and female rats exhibited comparable activity levels of catalase in all the tissues investigated. The higher activity levels of catalase as a result of exercise might be indicative of a compensatory measure to counteract the possible detrimental effects associated with oxidative stress.     

性类固醇激素对鲤鱼脑垂体生长激素基因表达的影响

建立核糖核酸酶保护法，检测性类固醇激素对鱼鱼脑垂体生长激素基因表达水平的影响。根据已知的鲤鱼生长激素ｃＤＮＡ设计ＰＣＲ引物，亚克隆克建新的含鲁鱼生长激素ｃＤＮＡ片段的质粒，并以此作为模板，体外转录合成鲁鱼生长激素的反义ＲＮＡ探针，用以检测鲤鱼脑垂体中的生长激素ｍＲＮＡ水平，处于性腺成熟早期的雌性鲤鱼埋植雌二醇５天或１０天后，血液中生长激素水平均显著高于对照组，但其脑垂体的生长激素ｍＲＮＡ水平均没有