Seawater teleosts: evidence for a sodium-potassium exchange in the branchial sodium-excreting pump

The net sodium extrusion rate by the gill of the seawater-adapted euryhaline flounder is identical to the potassium influx. The excretion of sodium is blocked in K(+)-free seawater solutions. The instantaneous sodium outflux readjustment pattern of flounders transferred from seawater to solutions of various sodium chloride or potassium chloride concentrations is consistent with the hypothesis of a linkage between Na(+) outflux and K(+) influx through a common exchange carrier. External Na(+) and K(+) compete for this comnmonz carrier. It is suggested that the exchange diffusion mechanism (linkage of sodium influx and outflux) and the high internal sodium turnover rate which characterizes all seawater teleosts are the results of this competitive process. The sodium-potassium dependent adenosine triphosphatase system occurring in the gill of the seawater teleosts may play a central role in this sodium-potassium exchange pump.     

Steelhead migration: potential temperature effects as indicated by gill adenosine triphosphatase activities

Yearling steelhead trout held in fresh water at cold temperatures (6.5 degrees or 10 degrees C) showed an increase in gill microsomal Na(+), K(+)-stimulated adenosine triphosphatase activity during parr-smolt transformation, whereas trout held in warm water (15 degrees or 20 degrees C) did not. Adenosine triphosphatase activity increased and other indications of transformation were observed in fish transferred from warm to cold water, whereas the reverse occurred on transfer from cold to warm water.     

海水和淡水养殖凡纳滨对虾肠道和鳃的菌群结构分析

运用Miseq高通量测序技术,分析凡纳滨对虾虾苗及其在海水和淡水2种养殖条件下生长到体长9~10 cm时的肠道和鳃的菌群结构。结果显示:虾苗、肠道和鳃样品在门水平上菌群均以厚壁菌门和变形菌门为主,但丰度差异较大;在属水平上,虾苗菌群以乳球菌属(36.1%)、未成功分属的γ–变形菌纲的菌株(25.5%)、芽孢杆菌属(13.5%)、Solibacillus(7.9%)、假单胞菌属(5.0%)和节杆菌属(2.5%)为主,鳃的菌群以乳球菌属、芽孢杆菌属、Solibacillus、假单胞菌属和节杆菌属为主,肠道菌群在海水养殖中的以发光杆菌属(22.9%)、弧菌属(18.2%)、乳球菌属(13.3%)、纤维弧菌属(8.0%)、希瓦氏菌属(5.5%)和芽孢杆菌属(5.4%)为主,而在淡水养殖中的以希瓦氏菌属(57.4%)、乳球菌属(18.8%)和芽孢杆菌属(6.3%)为主,弧菌丰度小于0.1%。养殖条件对凡纳滨对虾鳃中菌群结构影响较小,但对肠道菌群结构影响较大。     

急性盐度胁迫对紫石房蛤(Saxidomus purpurata)鳃组织结构及4种酶活性的影响

为探明急性盐度胁迫对狭盐性贝类紫石房蛤(Saxidomus purpurata)组织形态结构及生理生化的影响,研究了急性高盐(盐度35)和低盐(盐度15)胁迫下紫石房蛤鳃组织显微结构、Na+/K+-ATP酶和体腔液、鳃组织中SOD、CAT和POD 3种非特异性免疫因子的变化。鳃组织结构变化结果显示,与自然海水对照组相比,急性盐度胁迫实验组紫石房蛤鳃丝间距均呈现显著差异。盐度胁迫3 h起,低盐胁迫组紫石房蛤鳃丝皱缩程度和鳃间距与自然海水组相比总体呈现随胁迫时间增加而增大的趋势;高盐胁迫组鳃丝则表现为先皱缩后饱满,鳃间距呈逐渐缩小后逐步增大的趋势;低盐胁迫各时间点,鳃丝形态结构变化较相对应的高盐胁迫组明显。紫石房蛤鳃组织Na+/K+-ATP酶在急性低盐胁迫下活力升高,急性高盐胁迫下活力降低。24 h低盐和高盐度急性胁迫对紫石房蛤SOD、CAT和POD酶活力的影响呈现组织特异性。体腔液中以SOD率先对盐度胁迫产生应答,鳃组织中则以POD的响应最为快速。急性高盐胁迫下紫石房蛤体腔液中SOD和CAT活力在胁迫1 h、3 h后无明显变化,胁迫5 h后显著上升;胁迫7 h后显著下降;胁迫24 h后又显著上升,变化趋于一致(P0.05)。急性低盐胁迫下紫石房蛤体腔液中CAT和POD酶活力分别在7 h和3 h显著下降至最低点,之后逐步趋于对照组水平(P0.05)。结果提示,急性盐度胁迫下紫石房蛤体腔液和鳃组织中SOD、CAT和POD 3种非特异性免疫因子及鳃组织中Na+/K+-ATP酶的响应方式不同,紫石房蛤可能通过改变鳃组织形态结构从而适应外界盐度的骤然变化。     

DDT: disrupted osmoregulatory events in the intestine of the eel Anguilla rostrata adapted to seawater

The drinking of seawater and absorption of water along with sodium across the intestinal epithelium are well-known osmoregulatory events in marine teleosts. The insecticide DDT impairs fluid absorption in intestinal sacs from eels adapted to seawater. Furthermore, this functional impairment has an enzymatic basis; DDT also inhibits the (Na(+) and K(+)) activated, Mg(2+)-dependent adenosine triphosphatase in homogenates of the intestinal mucosa. Thus, the extreme sensitivity of teleosts to organochlorine pollutants may involve the disruption of osmoregulatory transport mechanisms.     

牙鲆对海水中铜的吸收、积累和排放规律

研究了牙鲆Paralichthysolivaceus内脏、肌肉、鳃组织对海水中Cu的吸收、积累和排放规律,以及海水中总有机碳(TOC)浓度和不同种类配体对Cu吸收的影响。试验结果表明,当Cu浓度为0 5mg/L时,各组织内Cu蓄积量随暴露时间的增加而增大,第13d均达到吸收平衡,各组织Cu蓄积量为内脏(971 89mg/kg干重)>肌肉(204 99mg/kg干重)>鳃(90 04mg/kg干重)。试验进行13d后,将牙鲆移入清洁海水中排放,结果表明,随着排放时间的增加,各组织Cu蓄积量下降,第8d接近排放平衡,各组织Cu排出率为肌肉(89%)>鳃(86 5%)>内脏(83 7%)。海水中TOC浓度及不同种类的配体对牙鲆吸收、蓄积Cu有明显影响,当TOC浓度相同时,孔石莼Ulvapertusa分泌物比牙鲆分泌物更能降低Cu的生物有效性;当配体相同时,随着TOC浓度的升高,各组织Cu蓄积量均明显下降,表明海水中TOC能降低Cu的生物有效性;海水中Cu2+的表观络合容量(ACu)随着TOC浓度的增加有明显上升趋势,并与TOC浓度呈线性相关。     

日粮中锰对公鸡胆固醇含量及ATP酶活性的影响

摘要经添加锰0(Ⅰ组)、50(Ⅱ组)、100(Ⅲ组)和300(Ⅳ组)PPM日粮处理后的种用公鸡,检测其胆固醇含量和三磷酸腺苷酶(ATP酶)活性。结果表明,缺锰或高锰日粮使肝脏、睾丸匀浆中胆固醇含量下降,血清、肝脏和睾丸匀浆中ATP酶活性降低。结果提示,日粮中锰含量的高低对胆固醇的合成有影响作用,而这种影响作用同锰引起的ATP酶活性的改变以及ATP供能速率的变化有关。     

Sodium and potassium effects on skeletal muscle microsomal adenosine triphosphatase and calcium uptake

The relationship between the (Na(+) and K(+))-activated adenosine triphosphatase enzyme system implicated in sodium-transport by cell membranes and the calcium-activated adenosine triphosphatase, which is generally associated with calcium uptake, was examined in microsomes from skeletal muscle. Whereas sodium and potassium did not modify the relatively low adenosine triphosphatase activity seen in the absence of calcium, a pattern similar to that of the sodium-transport enzyme system was seen afer the addition of CaCl(2). The calcium-activated adenosine triphosphatase was stimulated equally by sodium or potassium alone, but both the rate and extent of calcium uptake were enhanced more by potassium than by sodium at concentrations below 0.12 mole per liter. In the absence of either of these ions addition of calcium failed to activate adenosine triphosphatase although significant amounts of calcium were taken up by the microsomes.     

Central neuron initiation of periodic gill movements

In Aplysia periodic spontaneous gill movements are controlled by activity endogenous to the abdominal ganglion. These movements were still observed when only the ctenidio-genital nerve was left intact between the ganglion and the gill. One kind of spontaneous gill movement (one per 5 minutes at 15 degrees C) was correlated with the expression of activity of interneuron II; others were not. With reference to this kind of spontaneous gill movement, four types of central neurons in the ganglion send processes to the gill via the nerve. Two cell types (ii, iii) are inhibited and the other two (i, iv) are excited. Two types (i, ii) elicited gill movement-one type activating large gill areas elicited spontaneous gill movements, and the other activating specific gill regions did not participate in the spontaneous gill movements. The value of this preparation in studying the role of central neurons eliciting specific patterned movements and the temporal organization of their activity is shown.     

雌性三角帆蚌外鳃组织形态周年变化及低氧胁迫对外鳃组织形态和酶活性影响

通过石蜡切片观察雌性三角帆蚌外鳃组织形态周年变化,并探究低氧环境对雌性三角帆蚌外鳃组织形态及酶活性的影响。结果表明,雌性三角帆蚌外鳃鳃瓣1月最薄,至5月增至最厚,较1月显著增厚173.86%,随后鳃瓣逐渐变薄,其鳃小腔宽度随鳃瓣厚度增厚也显著增大,至6月增至最宽较1月显著增宽171.22%,随后鳃小腔逐渐变窄,且3—6月在雌性三角帆蚌外鳃发育为育儿囊,其中发现大量早期胚胎。在低氧环境下,乳酸脱氢酶(LDH)活性在1～5 d逐渐升高,第5天达到最大值,较对照组显著提升131.1%,5～9 d缓慢下降;超氧化物歧化酶(SOD)活性在1～7 d逐渐下降,在第7天达到最小值,较对照组显著降低40.53%,7～9 d缓慢上升;过氧化氢酶(CAT)活性在1～7 d逐渐上升,7～9 d无明显变化,第7天活性最高,较对照组显著提升91.34%,琥珀酸脱氢酶(SDH)活性在1～9 d呈下降趋势,最低值出现在第9天,较对照组显著降低68.9%;低氧胁迫5 d后,外鳃侧纤毛较对照组增宽了79.58%,外鳃小水管较对照组增宽了248.73%。本研究分别为怀卵期雌性三角帆蚌外鳃组织结构变化和低溶氧对雌性三角帆蚌...     

Actomyosin-like protein isolated from mammalian brain

A protein with characteristics similar to actomyosin has been isolated from whole brain of rat and cat. It is soluble in 0.6 molar potassium chloride and insoluble in 0.1 molar potassium chloride. It superprecipitates with magnesium ions and adenosine triphosphate. It has adenosine triphosphatase activity stimulated by either magnesium or calcium ions. Both superprecipitation and adenosine triphosphatase activity are inhibited by p-chloromercuribenzoate and Mersalyl but not by ouabain.     

Renal concentrating mechanism: possible role for sodium-potassium activated adenosine triphosphatase

Sodium-potassium activated adenosine triphosphatase activity was found to be almost twice as high in renal medulla as in cortex. Infusion of digoxin, a specific inhibitor of the enzyme, into one renal artery of the dog resulted in unilateral natriuresis, impaired concentrating capacity, and reduction of the enzyme activity in both cortex and medulla. It is suggested that the sodium-potassium adenosine triphosphatase plays an important role in urine concentration mechanisms.     

力竭性运动对日本黄姑鱼SOD和AKP酶活性的影响

[目的]研究力竭性运动前后日本黄姑鱼血清、鳃丝和肝脏中SOD酶活性、AKP酶活性和蛋白质水平的变化规律。[方法]以日本黄姑鱼为研究对象,采用超氧化物酶(SOD)测试盒和碱性磷酸酶(AKP)测试盒和考马斯亮蓝结合法分别对其SOD酶、AKP酶活性和蛋白含量进行测定。[结果]力竭性运动后,日本黄姑鱼SOD和AKP活性都急剧下降,血清、鳃丝和肝脏中SOD酶活性大小顺序是血清肝脏鳃丝,AKP酶活性的高低顺序为鳃丝肝脏血清,蛋白含量变化不显著。[结论]该研究为日本黄姑鱼的疾病防治提供理论依据和实践基础。     

Tritiated digoxin binding to (Na+ + K+)-activated adenosine triphosphatase: possible allosteric site

Tritiated H(3)-digoxin specifically binds to a cardiac (Na(+) + K(+))-activated adenosine triphosphatase. In the presence of adenosine triphosphate and other nucleoside di- and triphosphates, binding is stimulated by sodium ion, the apparent rate constant being similar to that reported for phosphorus-32 incorporation from adenosine triphosphate and for the adenosine triphosphatase activity. In the presence of magnesium, manganese, inorganic phosphate, or other ions, sodium ion inhibits binding. The data support an allosteric type of sodium-potassium ion pump.     

鳙鳃凝集素的稳定性及细胞凝集作用

[目的]为了探明鳙鳃凝集素在各种条件下的稳定性及其细胞凝集活性。[方法]测定经各种条件处理过的鳙鳃凝集素样品的血凝活性,评价其稳定性;通过镜检测定鳙鳃凝集素对微藻细胞及各种微生物细胞的凝集作用。[结果]琥珀酰化修饰、胰蛋白酶水解、SDS及β-巯基乙醇处理均使鳙鳃凝集素活性大大降低;在设定的处理浓度下,二甲基亚砜、NaC l及三氟乙酸对其活性没有影响;鳙鳃凝集素能专一地凝集雨生红球藻及哈维氏弧菌和鳗弧菌。[结论]鳙鳃凝集素稳定性受各种因素影响,能够选择性地凝集雨生红球藻及2株鱼类病原弧菌。     

Actin-myosin interaction: inhibition of the myosin adenosine triphosphatase by actin

In the absence of magnesium ion, the addition of actin to myosin in a 1 :4 ratio has a strong inhibitory effect on the adenosine triphosphatase activity, in contrast to the well-known activating effect of actin in the presence of magnesium ion. This finding suggests that both effects result from a conformational change in the active site of the myosin adenosine triphosphatase.     

Cochlear function and sodium and potassium activated adenosine triphosphatase

The maintenance of the cation gradients between endolymph and perilymph in the cochlea requires the operation of a cation pump. An adenosine triphosphatase system activated by sodium and potassium is present in high activity in the cochlear membranes (tegmentum vasculosum and stria vascularis). The cochlear microphonic potential is inhibited by perilymphatic perfusion of ouabain and erythrophleine. Since the microphonic potential depends on the high concentration of potassium ions in the endolymph, our findings strongly suggest the operation of an adenosine triphosphatase cation pump system activated by sodium and potassium, in the generation of cochlear cation gradients.     

中国鲎同工酶组织器官特异性表达

采用垂直聚丙烯酰胺凝胶电泳技术,分析了中国鲎6种组织器官（肝胰腺、心脏、肠、鳃、肌肉和黄色结缔组织）的乙醇脱氢酶（ADH）、山梨醇脱氢酶（SDH）、酯酶（EST）、过氧化氢酶（CAT）、天冬氨酸转化酶（AAT）、苹果酸脱氢酶（MDH）和苹果酸酶（ME）等7种同工酶的活性和分布,并对其酶谱的表型进行了分析.结果表明,中国鲎的同工酶系统存在不同程度的组织特异性.乙醇脱氢酶在鳃和黄色结缔组织中不表达;山梨醇脱氢酶在鳃中不表达;酯酶、过氧化氢酶和苹果酸脱氢酶在6种组织器官中均有表达,但表达活性存在差异;而天冬氨酸转化酶Aat-1位点在鳃中不表达.     

湛江市养殖墨西哥湾扇贝中14种微量元素的分布特征及其膳食暴露评估

为阐明湛江市养殖墨西哥湾扇贝中14种微量元素的含量及分布特征，并进行膳食暴露风险评估，采用电感耦合等离子体质谱法（inductively coupled plasma mass spectrometry, ICP-MS）测定了6个养殖区域扇贝全部软体部分、性腺、外套膜、消化腺、闭壳肌、鳃和海水中14种微量元素的含量，通过目标危害系数（target hazard quotient,THQ）评估有害微量元素潜在的膳食暴露风险。结果表明，全部样品中14种微量元素均有检出，含量由高到低依次为Mn>Fe>Zn>Sr>As>Cd>V>Cu>Co>Ba>Pb>Cr>Ni>Ga，并且表现出区域差异性。微量元素主要分布在扇贝的性腺、消化腺和鳃中，养殖区域海水中与扇贝中Cd的含量变化趋势相同，扇贝体内的微量元素含量存在季节性差异。扇贝中As与Cd含量间呈极显著正相关（P<0.01），可能对人体有害微量元素的复合目标危害系数（total target hazard quotient, TTHQ）值为0.208(<1)。...     

离子液体对斑马鱼急性毒性及保护酶活性的影响

[目的]探讨离子液体对斑马鱼急性毒性及保护酶活性的影响。[方法]采用半静态水体染毒法测定1,2-二甲基咪唑对斑马鱼的急性毒性,并对1,2-二甲基咪唑进行了安全性评价。同时测定了不同作用时间后斑马鱼体内不同组织(鳃、肝脏和肌肉)抗氧化酶的活性。[结果]处理96 h后,1,2-二甲基咪唑对斑马鱼的LC50和LC20值分别为120.815和111.401 mg/L。1,2-二甲基咪唑(LC20和LC50)处理的斑马鱼鳃、肝脏和肌肉的CAT活性均呈现出先诱导后抑制的趋势。1,2-二甲基咪唑(LC20和LC50)处理的斑马鱼的鳃、肝脏和肌肉的SOD活性均呈现出始终抑制的趋势。1,2-二甲基咪唑(LC20和LC50)处理的斑马鱼鳃的POD活性的影响呈现出先诱导后抑制的趋势,肝脏POD活性的影响从经过LC20浓度处理来看呈现出先诱导后抑制的趋势,从经过LC50浓度处理来看呈现出抑制——诱导——抑制的趋势,1,2-二甲基咪唑对斑马鱼肌肉POD活性呈现出始终抑制的趋势。[结论]1,2-二甲基咪唑在斑马鱼体内积累显著影响斑马鱼体内CAT、SOD和POD的活性,降低斑马鱼体内自由基的清除能力,从而对其产生毒害作用。