应激过程中骨骼肌内热休克蛋白(HSPs)的变化及其调控机制

在应激反应时,细胞可快速产生一系列蛋白质,这些蛋白质即被称为热休克蛋白(HSP)。人们认为HSPs是一种分子伴侣,在保持细胞稳态当中起着十分广泛的作用。骨骼肌中所表达的HSPs包括小分子HSP家族(泛素、alpha B-晶体蛋白、HSP20、HSP27),HSP70、HSP60、HSP90等。骨骼肌是一个非常复杂的系统,其中的收缩蛋白是由各种不同的肌肉纤维类型所组成,每一种肌纤维均具有其各自的生化组成和功能特征。HSPs 的表达与肌纤维的类型有关。在肌病或体育锻炼过程中HSPs有明显的变化,然而HSP的诱导及调控的分子机制以及它在维持肌肉功能方面的作用尚未完全明了。本文主要阐述了骨骼肌中HSP的变化及其调控的分子生物学机制。     

光对美洲蛙肌肉纤维衍射强度的分布研究

肌原纤维是由粗丝和细丝重迭而成的Ａ带和只含细丝的Ⅰ带组成，形成了天然光栅，因此可用光学方法探讨肌原纤维分子结构及其动力学问题。试验表明，单色光通过美洲蛙肌原纤维后，衍射光左右两端为非对称性，且左右条纹锋值间隔随肌原纤维节长度增大而减小。肌肉运动有张有弛，于是肌原纤维长度有变异，共变异与非对称有关。当肌原纤维长度增加时，左右两端强度差异变大，而相对应条纹的锋值间隔距离变小。这一现象与布拉格方程和折射     

鱼组织中氟喹诺酮类药的HPCE多残留检测方法的建立

建立了以伊诺沙星为内标,环丙沙星、恩诺沙星、沙拉沙星、二氟沙星在鱼组织中的毛细管电泳多残留检测方法。研究了缓冲溶液的类型,pH值,有机试剂添加等电泳条件.得到最佳的缓冲溶液是含10ml/L乙腈的pH5.0的磷酸氢二钠-柠檬酸缓冲溶液。用C18固相萃取柱浓缩和净化处理,用二极管阵列检测器进行检测(275nm)。结果,四种药物在组织中的溶度25￣400μg/kg范围内R>0.999,线性关系良好。环丙沙星,恩诺沙星,沙拉沙星和二氟沙星回收率分别为75.2%,79.7%,80.1%,79.2%。恩诺沙星的检测限低于25μg/kg,其余的检测限均为25μg/kg,,方法的日内变异系数小于13.5%,日间变异系数小于12.3%。该方法简单快速,经济环保,适用于大量阳性样本的筛选。     

饥饿对于花[鱼骨]肌肉和血清主要生化指标的影响

于20.50±2.15℃的条件下,在室内1 m3的水泥池中进行了为期42 d的饥饿实验,分别在实验开始后的1、7、14、28、42 d取样,以观察饥饿对花背部肌肉和血清主要生化指标的影响。结果表明:花对饥饿忍受能力较强,在实验期间无死亡现象;在饥饿初期花首先快速利用肌肉脂肪作为能量供给,后期则主要以肌肉蛋白作为能量来源,肌肉的水分含量不断升高,灰分含量则以不规则的锯齿状变化;花血清中的血糖对饥饿特别敏感,在14 d内显著下降(P<0.05),之后,保持在动态的恒定水平,而总蛋白质、甘油三脂、总胆固醇、谷丙转氨酶、谷草转氨酶、碱性磷酸酶则在饥饿实验中以波浪状变化并呈下降趋势。     

加米霉素注射液特殊安全性试验研究

通过豚鼠、大白兔的皮肤致敏、皮肤刺激、肌肉刺激、红细胞溶血试验,考察加米霉素注射液的安全性。试验用新西兰大白兔8只进行皮肤刺激,染毒剂量为加米霉素注射液0.5 mL/只(规格:150 mg/mL);用白化豚鼠进行皮肤致敏试验,按0.5 mL/kg剂量,以豚鼠背部左侧皮肤进行染毒;用新西兰大白兔24只,进行肌肉刺激试验,在右侧股四头肌注入6、12、30 mg/kg bw,左侧股四头肌注入同样体积的灭菌0.9%氯化钠溶液作对照;用新西兰大白兔2只,进行红细胞溶血试验,采用体外试管法进行,采心脏血50 mL,制成血细胞悬液,加入受试药物原液温育3 h。结果显示,皮肤刺激试验:受试物加米霉素注射液各个时间点的刺激反应积分均值为0;皮肤致敏试验:受试药物组和阴性对照组豚鼠的皮肤过敏反应率为0;肌肉刺激试验:给予受试物各个时间点的刺激反应积分均值为0;红细胞溶血试验:受试药物及阴性对照在3 h内红细胞全部下沉,上清液体均为澄明,溶液中未见棕红色或红棕色絮状沉淀。试验表明加米霉素注射剂无皮肤刺激性、不出现过敏反应、无肌肉刺激性、无溶血和凝聚作用,临床上可以肌肉注射使用。     

White muscle of masu salmon,Oncorhynchus masou masou,smolts possesses a strong buffering capacity due to a high level of anserine

Masu salmon, Oncorhynchus masou masou, fry were fed with diets containing three different levels of protein for 18 weeks, and the levels of free amino acids and related compounds in the white muscle were compared among the dietary groups and between smolts and parr. The anserine level in the white muscle of smolts was always higher than that of parr, while histidine and glycine levels in the former were always lower than those in the latter, irrespective of dietary treatments. A mixed solution of crystalline anserine, histidine and glycine simulating these amino acid levels in the white muscle of the smolts had a stronger buffering capacity in the physiological pH range than that simulating those levels present in parr. These results suggest that even in freshwater conditions, the white muscle of smolts possesses a more potent buffering capacity than the muscle of parr, for anaerobic burst swimming during the downstream migration. Moreover, the white muscle of smolts fed the high-protein diet had a significantly higher level of anserine than that of smolts fed the low- or intermediate-protein diets, and the solution mimicking the white muscle of smolts fed the high-protein diet showed the strongest buffering capacity among the mixed solutions tested. Thus, a diet with high-protein level could improve qualities of smolts.     

The roles of bone and muscle as phosphorus reservoirs during the sexual maturation of female Japanese eels, Anguilla japonica Temminck and Schlegel (Anguilliformes)

We sought to determine the organs that function as phosphorus (P) reservoirs for supplying this mineral to the ovary during the sexual maturation of the Japanese eel, Anguilla japonica (Anguilliformes). The P content of the ovary increased markedly during sexual maturation despite the lack of an extrinsic P supply (e.g., diet). This phenomenon suggests that the P that accumulated in the ovary was derived from other parts of the eel. In addition, the P content of bone dramatically decreased during maturation, as did the total bone weight. This result suggests that resorption of bone occurred during the sexual maturation of the eel. Whereas the P content and mass of muscle markedly decreased during maturation, the Ca and P contents of the skin (which was scaled) did not. The total (whole-fish) P content was constant throughout maturation. Together, our results suggest that almost all of the P lost from bone and muscle is incorporated in the ovary and that bone and muscle function as P reservoirs during the sexual maturation of the Japanese eel. This revised version was published online in August 2006 with corrections to the Cover Date.     

斑鳠的含肉率及肌肉营养评价

测定了4尾斑鱯的含肉率及其营养成分,并对其营养价值进行综合评定。该鱼(鲜样)含肉率 73.37％;肌肉中含粗蛋白 19.60％,粗脂肪 0.36％,粗灰分 1.20％,水分 3.18％,无氮浸出物0.33％。干物质中水解氨基酸总量84.63％,其中必需氨基酸36.19％,占氨基酸总量的 42.77％;游离氨基酸总量 593.96mg/100g;必需氨基酸指数为 53.18。认为斑鱯是一种营养价值较高的淡水优质品种。     

陆封型大西洋鲑肌肉营养成分分析

应用生化分析方法对养殖的陆封型大西洋鲑2龄和3龄鱼肌肉中的营养成分和蛋白质中氨基酸组成及含量进行了定量分析。结果显示：2龄和3龄陆封型大西洋鲑肌肉中蛋白质含量分别为19．85％和20．20％；脂肪含量为2．74％和4．73％；水分含量为76．30％和74．74％；灰分含量为2．59％和1．95％。陆封型大西洋鲑肌肉蛋白质中含有18种氨基酸，总量分别为17．88％和18．40％，其中10种人体必需氨基酸含量为9．15％和9．96％。     

Myofibrillar proteolysis by myofibril-bound serine protease from white croaker <Emphasis Type="Italic">Argyrosomus argentatus</Emphasis>

ABSTRACT:   The modori phenomenon is defined as heat-induced myofibrillar degradation caused by endogenous serine protease(s) of fish muscle during Kamaboko fish meat gel production. This study was undertaken to analyze myofibrillar proteolysis of white croaker Argyrosomus argentatus muscle, which is an ingredient of high quality Kamaboko, by myofibril-bound serine protease (MBSP) under conditions corresponding to the modori phenomenon. White croaker MBSP was stable between pH 2–11 and below 65°C, and about 60% of its initial activity remained after incubation for 2 h under the conditions at 65°C and pH 7.5. About 60% of the enzyme activity was suppressed by 0.5 M NaCl. White croaker MBSP degraded various myofibrillar proteins between 40 and 70°C and pH 6.0–9.0, and preferentially degraded myosin heavy chain rather than other myofibrillar proteins. The enzyme degraded the myosin heavy chain most strongly at 55°C and pH 7.0, and a major part of the bands of myosin heavy chain and its degradation products disappeared for a period of 2 h. These degradation characteristics are very similar to those observed during the modori phenomenon, indicating that MBSP could be a modori-inducing protease involved in the modori phenomenon of white croaker Kamaboko production.