新型柱前衍生-高效液相荧光检测法检测水产品中河豚毒素

在稀碱条件下,河鲀毒素(TTX)与次溴酸钠和尿素于一定温度下反应生成具有荧光性能的物质,该反应与已报道的TTX在强碱下生成C-9碱的碱解不同。本研究拟对该衍生反应所需条件进行详细研究,并尝试依据该反应建立一种新型的河鲀毒素荧光检测方法。荧光扫描光谱显示,产物最大激发波长(EX)为233 nm,最大发射波长(EM)为370 nm。该反应对p H要求比较严格,反应最适p H在11.6~11.9之间。对样品进行衍生检测获得最强荧光信号的条件为:次溴酸钠0.036~0.09 mol/L、尿素10~50 g/L、碳酸钠0.2~0.3 mol/L,温度75℃。样品检测结果显示,此衍生反应具有高度专一性,信号强度与TTX含量成正比,在0.01~10μg/m L质量浓度范围内线性方程为y=109.17x+0.3965,线性相关系数为0.999。依据该衍生反应建立柱前衍生–高效液相色谱荧光检测法检测水产品中河鲀毒素含量,检测限达到20μg/kg,平行样品检测相对标准偏差为0.44%~7.25%,准确度高。对河鲀、虾虎鱼和织纹螺产品检测表明,该反应特异性强,不易出现假阳性,可用于河鲀毒素检测的确证。     

暗纹东方鲀肝脏热去毒效果的研究

本文对暗纹东方肝脏热去毒效果的研究表明：1．河毒素在高于120℃的温度下不稳定,温度越高,稳定性越差;2．长江野生暗织东方肝脏在150℃加热4min、大运河中暗纹东方及人工养殖暗纹东方肝脏分别在150℃加热3．5min、3min,毒素基本去除。     

东海区黄鳍东方鲀寄生异尖线虫的鉴定及河鲀毒素检测

通过检查东海区283尾野生黄鳍东方鲀(Takifugu xanthopterus)样本,发现具有河鲀毒素的黄鳍东方鲀也受到线虫的感染。11月份黄鳍东方鲀体内异尖线虫感染情况最严重。通过形态学特征和线粒体DNA鉴定,黄鳍东方鲀组织内寄生的线虫为派氏异尖线虫(Anisakis pegreffii)。免疫组学分析发现异尖线虫体内含有河鲀毒素,进一步的高效液相色谱-质谱检测结果显示异尖线虫体内河鲀毒素含量为425 ng/g,这是首次发现寄生在东方鲀体内的线虫具有河鲀毒素。     

Frequent occurrence of the tetrodotoxin-bearing horseshoe crab <Emphasis Type="Italic">Carcinoscorpius rotundicauda</Emphasis> in Vietnam

Tetrodotoxin (TTX) was detected by HPLC and LC-MS/MS in specimens of the horseshoe crab Carcinoscorpius rotundicauda collected from Tan Hai village, Vung Tau province, Vietnam, where cases of poisoning due to the consumption of horseshoe crab have frequently been reported. The soft tissue from 10 out of the 12 specimens analyzed showed considerable levels of TTX, making them unsafe for human consumption (81.2 ± 50.3 MU/g). Paralytic shellfish poisoning (PSP) toxins were also detected in all of the specimens, but the levels were low. These findings show that the frequency of occurrence of C. rotundicauda specimens with a high level of TTX is significantly high, and that the TTX is responsible for the food poisonings caused by the consumption of C. rotundicauda in this area.     

Analytical challenges: determination of tetrodotoxin in human urine and plasma by LC-MS/MS

Tetrodotoxin (TTX) is a powerful sodium channel blocker found in puffer fish and some marine animals. Cases of TTX poisoning most often result from puffer fish ingestion. Diagnosis is mainly from patient's signs and symptoms or the detection of TTX in the leftover food. If leftover food is unavailable, the determination of TTX in the patient's urine and/or plasma is essential to confirm the diagnosis. Although various methods for the determination of TTX have been published, most of them are for food tissue samples. Dealing with human urine and blood samples is much more challenging. Unlike in food, the amount of toxin in the urine and blood of a patient is generally extremely low; therefore a very sensitive method is required to detect it. In this regard, mass spectrometry (MS) methods are the best choice. Since TTX is a very polar compound, there will be lack of retention on conventional reverse-phase columns; use of ion pair reagent or hydrophilic interaction liquid chromatography (HILIC) can help solve this problem. The problem of ion suppression is another challenge in analyzing polar compound in biological samples. This review will discuss different MS methods and their pros and cons.     

Tetrodotoxin (TTX) as a therapeutic agent for pain

Tetrodotoxin (TTX) is a potent neurotoxin that blocks voltage-gated sodium channels (VGSCs). VGSCs play a critical role in neuronal function under both physiological and pathological conditions. TTX has been extensively used to functionally characterize VGSCs, which can be classified as TTX-sensitive or TTX-resistant channels according to their sensitivity to this toxin. Alterations in the expression and/or function of some specific TTX-sensitive VGSCs have been implicated in a number of chronic pain conditions. The administration of TTX at doses below those that interfere with the generation and conduction of action potentials in normal (non-injured) nerves has been used in humans and experimental animals under different pain conditions. These data indicate a role for TTX as a potential therapeutic agent for pain. This review focuses on the preclinical and clinical evidence supporting a potential analgesic role for TTX. In addition, the contribution of specific TTX-sensitive VGSCs to pain is reviewed.     

河豚毒素及其代谢产物的研究进展

对河豚毒素及其代谢产物的理化性质、分析方法、在动物体内的分布及产生来源等进行了简单的概述,旨在为研究含毒动物体内积累河豚毒素的机制提供一些理论根据。     

The Structural Basis and Functional Consequences of Interactions Between Tetrodotoxin and Voltage-Gated Sodium Channels

Tetrodotoxin (TTX) is a highly specific blocker of voltage-gated sodium channels. The dissociation constant of block varies with different channel isoforms. Until recently, channel resistance was thought to be primarily imparted by amino acid substitutions at a single position in domain I. Recent work reveals a novel site for tetrodotoxin resistance in the P-region of domain IV.     

Tetrodotoxin as a tool to elucidate sensory transduction mechanisms: the case for the arterial chemoreceptors of the carotid body

Carotid bodies (CBs) are secondary sensory receptors in which the sensing elements, chemoreceptor cells, are activated by decreases in arterial PO(2) (hypoxic hypoxia). Upon activation, chemoreceptor cells (also known as Type I and glomus cells) increase their rate of release of neurotransmitters that drive the sensory activity in the carotid sinus nerve (CSN) which ends in the brain stem where reflex responses are coordinated. When challenged with hypoxic hypoxia, the physiopathologically most relevant stimulus to the CBs, they are activated and initiate ventilatory and cardiocirculatory reflexes. Reflex increase in minute volume ventilation promotes CO(2) removal from alveoli and a decrease in alveolar PCO(2) ensues. Reduced alveolar PCO(2) makes possible alveolar and arterial PO(2) to increase minimizing the intensity of hypoxia. The ventilatory effect, in conjunction the cardiocirculatory components of the CB chemoreflex, tend to maintain an adequate supply of oxygen to the tissues. The CB has been the focus of attention since the discovery of its nature as a sensory organ by de Castro (1928) and the discovery of its function as the origin of ventilatory reflexes by Heymans' group (1930). A great deal of effort has been focused on the study of the mechanisms involved in O(2) detection. This review is devoted to this topic, mechanisms of oxygen sensing. Starting from a summary of the main theories evolving through the years, we will emphasize the nature and significance of the findings obtained with veratridine and tetrodotoxin (TTX) in the genesis of current models of O(2)-sensing.     

南海常见河豚鱼品种及其毒素含量的研究

本文对南海采集的河豚鱼进行了品种鉴别,并采用直接竞争酶联免疫法研究了河豚鱼的毒性。试验结果表明,南海常见的6种河豚鱼棕斑腹刺鲀、暗鳍腹刺鲀、月腹刺鲀、黄鳍东方鲀、菊黄东方鲀和黑鳃兔头鲀;TTX在河豚鱼种和鱼体不同部位间的差异极显著,月腹刺鲀的毒性最强,卵巢毒力高达251.4MU。