Effects of purified components of jellyfish toxin (Stomolophus meleagris) on adenosine triphosphatase activities.

Toxin from the jellyfish Stomolophus meleagris was found to stimulate both Na⁺-K⁺ and mitochondrial Mg²⁺ ATPase activities at low toxin concentrations and to inhibit these ATPase activities at higher (> 0·2 mg/ml) concentrations. Using discontinuous membrane partition chromatography the toxin was fractionated into six fractions. Of these six fractions, one strongly activated when five inhibited mitochondrial Mg²⁺ ATPase. One fraction strongly activated, a second mildly activated, while the other four inhibited Na⁺-K⁺ ATPase about 50 per cent. Only two fractions affected oligomycin-insensitive ATPase, and both of these exhibited a mild stimulation. It is concluded that the ability of this toxin to alter membrane permeability to Na⁺ is due, at least in part, to components in the toxin which act directly on ATPase.     

Effects of purified components of jellyfish toxin (Stomolophus meleagris) on active sodium transport.

Using preparative isoelectric focusing and discontinuous membrane partition chromatography, three fractions which alter sodium transport were isolated from venom of the jellyfish Stomolophus meleagris. A fraction which inhibited sodium transport was partially purified and found to possess a molecular weight of approximately 50,000 and an isoelectric point of 3·30. This component, which appeared to affect active sodium transport at the enzyme level, was also found to produce hemorrhage and necrosis in mice. Two fractions were purified which increased sodium transport in a passive manner and possessed molecular weights of 10,000–50,000, and greater than 300,000, respectively, and have isoelectric points of 4·15 and 5·30. The fraction of 300,000 mol. wt contained most of the toxicity. It is concluded that the immediate pharmacological response to jellyfish toxin possibly is due to components which increase sodium transport, while the apparent delayed response is probably due to a component of the toxin which acts in a cardiotonic, ouabain-like manner.     

Isolation and in vitro partial characterization of hemolytic proteins from the nematocyst venom of the jellyfish Stomolophus meleagris

Jellyfish venom contains various toxins and can cause itching, edema, muscle aches, shortness of breath, blood pressure depression, shock or even death after being stung. Hemolytic protein is one of the most hazardous components in the venom. The present study investigated the hemolytic activity of the nematocyst venom from jellyfish Stomolophus meleagris. Anion exchange chromatography, DEAE Sepharose Fast Flow, and gel filtration chromatography, Superdex200 had been employed to isolate hemolytic proteins from the nematocyst venom of jellyfish S. meleagris. Hemolysis of chicken red blood cells was used to quantify hemolytic potency of crude nematocyst venom and chromatography fractions during the purification process. Native-PAGE profile displayed one protein band in the purified hemolytic protein (SmTX); however, two protein bands with apparent molecular weights of ～45 kDa and 52 kDa were observed in the reducing SDS–PAGE analysis. Approximately 70 μg/mL of SmTX caused 50% hemolysis (HU₅₀) of the erythrocyte suspension. The hemolytic activity of SmTX was shown to be temperature and pH dependent, with the optimum temperature and pH being 37 °C and pH 5.0. The present study is the first report of isolation and partial characterization of hemolytic proteins from the nematocyst venom of the jellyfish S. meleagris. The mechanism of the hemolytic activity of SmTX is not clear and deserves further investigation.     

Cardiac effects of toxin A-III from the heteronemertine worm Cerebratulus lacteus (Leidy)

Reversible and irreversible (cytolytic) effects of pure Cerebratulus toxin A-III, a heteronemertine polypeptide toxin, upon canine cardiac Purkinje fibers were investigated using standard microelectrode techniques and a fluorometric assay for measuring release of cell protein. Sublytic concentrations (0·25-1·0 μg/ml) of A-III reversibly depolarized the resting membrane if the duration of exposure was brief. Tetrodotoxin and saxitoxin at concentrations which block the Purkinje fiber sodium channel failed to prevent the A-III induced resting membrane depolarization. The amplitude and duration of the action potential were also reversibly reduced by low concentrations of A-III. The Ca²⁺-dependent slow response observed in TEA-Tyrode was also blocked without alteration of the resting potential. Increasing [Ca²⁺]₀ reduced the effectiveness of A-III in altering transmembrane potentials. Higher concentrations (> 2 μg/ml) of A-III irreversibly damaged Purkinje cells, causing release of intracellular macromolecular constituents. Toxin A-III actions upon cardiac tissue were very similar to those reported by Ho et al. (1975) for an elapid snake cardiotoxin.     

Contractile effects of jellyfish toxin extracted from Carybdea rastonii on isolated rabbit aorta

Effects of the toxic component of jellyfish (Carybdea rastonii) (pCrTX) on the smooth muscle tension of isolated rabbit thoracic aorta were examined. pCrTX, at concentrations higher than 10(-7) g/ml, caused slowly developing tension that reached its maximum after about 1 hr. This contraction was partially inhibited by pretreatment of the tissue with phentolamine (5 X 10(-6) M) or indomethacin (10(-5) M). The contraction induced by pCrTX was partially inhibited by nicardipine (10(-7) M) and markedly augmented by Bay k8644 (10(-6) M). In low-Na+ solution, the rate of rise of the pCrTX-induced contraction was significantly reduced. Removal of external Ca2+ inhibited the pCrTX-induced contraction by about 30%, while chlorpromazine, trifluoperazine, prenylamine and papaverine (10(-4) M) completely inhibited the contraction. pCrTX itself did not cause any contraction in saponin-skinned smooth muscle and had no effect on the Ca2+-induced contractile tension. It has been reported that pCrTX-induced contraction is attributable to the release of endogenous catecholamines and also to the increase in Ca2+ influx in smooth muscle (Azuma et al., 1986). The present results confirmed the previous suggestion and further suggested that a portion of the contraction is due to release of prostaglandin(s) and also to the direct effect on smooth muscle which is not dependent on Ca2+ influx.     

Apoptosis induced by box jellyfish (Chiropsalmus quadrigatus) toxin in glioma and vascular endothelial cell lines.

This study was made to investigate whether Chiropsalmus Quadrigatus toxins (CqTX), which isolated from box jellyfish C. Quadrigatus venom, could induce apoptosis in human U251 and rat C6 malignant glioma cells and transformed vascular endothelial ECV 304 cell lines. Cell viability was estimated by MTT assay. Apoptosis was evaluated using TdT (terminal deoxynucleotidyl transferase)-mediated dUTP nick-end labeling (TUNEL) method and DNA gel electrophoresis. Furthermore, the expression of p53 protein was examined immunohistochemically in the U251 cells. After the CqTX treatment, the growth of all cell lines was inhibited, the fragmented DNA was observed and some cells became TUNEL positive. The expression of p53 protein was increased in the tested U251 cells. The results suggested that CqTX induced apoptosis in these cell lines. The promotion of the p53 expression might be one mechanism of apoptosis induced by CqTX in the glioma cells.     

Cardiovascular effects of Nemopilema nomurai (Scyphozoa: Rhizostomeae) jellyfish venom in rats

Over the past few years, populations of the giant jellyfish Nemopilema nomurai (Scyphozoa: Rhizostomeae) have increased dramatically in the waters of China, Korea, and Japan without any definitive reason. This has resulted in severe damage to fisheries in the areas. During a pilot study, we observed that the venom of N. nomurai produced a functional cardiac depression in mice. However, the mechanism of action was not examined. In the present study, we investigated the cardiovascular effects of nematocyst-derived venom from N. nomurai in anesthetized rats. Venom (0.1-2.4 mg protein/kg, i.v.) produced dose-dependent hypotension (65+/-12% of initial at a cumulative dose of 3 mg/kg) and bradycardia (80+/-5% of initial at a cumulative dose of 3 mg/kg). At the highest dose, this was characterized by a transient decrease in blood pressure (phase 1) followed by a return to basal level and then a slower decrease in blood pressure (phase 2). Venom also produced a decrease in rate and force of contraction in the rat isolated atria. Interestingly, venom induced a contraction of isolated aortic rings which was blocked by felodipine but not by prazosin, suggesting the contraction is mediated by calcium channel activation. These results suggest that the negative inotropic and chronotropic effects of the venom of N. nomurai may be due to a direct effect on the heart.     

Isoform-specific effects of a novel BmK 11(2) peptide toxin on Na channels.

BmK 11(2) is a 7216Da polypeptide toxin purified from the venom of the scorpion Buthus martensii Karsch. Nanomolar concentrations of the toxin prolong amphibian nerve action potentials without attenuation of the amplitude. The pharmacological action of the toxin and its sequence similarity to other alpha-scorpion toxins suggest that BmK 11(2) selectively alters voltage-gated Na channels. In order to test whether BmK 11(2) preferentially modulates the gating or kinetics of certain channel isoforms, we applied BmK 11(2) to muscle, heart and neuronal Na channels. 100nM BmK 11(2) increased the peak current amplitude of skeletal muscle (micro1) and neuronal (N1E-115) Na currents by 40 and 20%, respectively, and reduced the cardiac Na (hH1) current by 15%. The toxin slowed current decay of all isoforms, most prominently in N1E-115 (tau(BmK)/tau(Control)=12), micro1 (11), and less so for hH1 (1.3). BmK 11(2) shifted the voltage dependence of activation of micro1 and N1E-115 currents. BmK 11(2) had no effect on steady-state inactivation, use-dependent availability, and the kinetics of entry into slowly recovering inactivated states.     

Calcium-dependent contractile response of arterial smooth muscle to a jellyfish toxin (pCrTX: Carybdea rastonii).

The purpose of the present experiments was to investigate the pharmacological mechanisms of the vasoconstriction caused by the toxin (pCrTX) which had been partially purified from the tentacles of the jellyfish Carybdea rastonii ('Andonkurage'). pCrTX (0.1 to 10 micrograms ml-1) produced a tonic contraction of rabbit aortic strips, which was nearly abolished in Ca2+-free medium and was significantly reduced by verapamil or diltiazem. pCrTX stimulated 45Ca2+-influx and this effect was markedly attenuated by verapamil. pCrTX-induced vasoconstriction was significantly attenuated by phentolamine, 6-hydroxydopamine (6-OHDA) and in low Na+-medium, but not by bretylium, guanethidine, reserpinization or tetrodotoxin (TTX). pCrTX continuously and significantly increased the 3H-efflux from [3H]-noradrenaline preloaded aortic strips and this effect was completely inhibited by pretreatment with 6-OHDA and in Ca2+-free medium, but not by phentolamine, bretylium, guanethidine or TTX. A single exposure to pCrTX for 30 min greatly reduced the contractile responses to tyramine, nicotine and transmural electrical stimulation, but not those to noradrenaline or KC1. In addition, incorporation of [3H]-noradrenaline was reduced. Pretreatments with chlorphenylamine or indomethacin failed to modify the contractile response to pCrTX. These results suggest that the pCrTX-induced vasoconstriction is caused by a presynaptic action, releasing noradrenaline from the intramural adrenergic nerve terminals, and by a postsynaptic action, which consists at least in part of stimulation of the transmembrane calcium influx. Both pre- and postsynaptic actions depend on the external calcium concentration. The data further suggest that pCrTX damages the noradrenaline uptake and/or storage mechanisms without damaging postsynaptic contractile systems.     

水母毒素心血管活性研究进展

简要介绍水母毒素的心血管毒性及其作用机制,重点讨论了Ca2+通道、儿荼酚胺受体、胆碱能受体等与水母毒素心血管效应的关系.     

Investigations into the cardiotoxicity of a toxin from the nematocysts of the jellyfish, Cyanea capillata.

The action of Cyanea toxin-containing material on active cation transport enzymes from human erythrocyte membranes and on the beating behaviour of cultured neonatal rat heart cells has been examined. The heat labile cardiotoxic principle had no specific effects on the activity of enzymes involved in active transport of Na⁺, K⁺ and Ca²⁺ which would account for the cardiotoxicity previously ascribed to marked disturbances in the distribution of these ions. Exposure to Cyanea toxin produced predictable effects in single cultured heart cells and each treated cell went through the same progression of arrhythmic changes which consisted of an initial increase in rate, followed by variations in rate, rapid fluttering, an intermediate dormant period, fibrillation (asynchronous rapid contractions) and a final cessation of all activity. Arrhythmic changes were compatible with the toxin-induced electrophysiological changes previously described for rat atrial tissue.     

Cardiac effects of sodium stibogluconate.

Sodium stibogluconate although potentially cardiotoxic is the drug of choice for Kalaazar and cutaneous leishmaniasis due to Leishmania braziliensis. Increasing use of this drug in the British Army has necessitated a formal evaluation of its cardiac side-effects. Consequently a detailed study of the cardiac effects of sodium stibogluconate was undertaken in 22 male soldiers using for the first time modern non-invasive techniques. Intravenous sodium stibogluconate 600 mg daily for 10 days did not affect blood pressure, heart rate, left ventricular contractile function or rhythm. Electrocardiography showed a reversible reduction of T wave amplitude.     

Pharmacologically distinct cardiovascular effects of box jellyfish (Chironex fleckeri) venom and a tentacle-only extract in rats

Using a recently developed technique to extract jellyfish venom from nematocysts, the present study investigated the in vivo cardiovascular effects of Chironex fleckeri venom and tentacle extract (devoid of nematocysts). In anaesthetised rats, venom (10 microg/kg, i.v.) produced a transient pressor response (23+/-4 mmHg) followed, in two of five animals, by cardiovascular collapse. Tentacle extract (100 microg/kg, i.v.) produced a more prolonged hypertensive effect (31+/-3 mmHg) without cardiovascular collapse. Prazosin (50 microg/kg, i.v.) did not have any significant effect on the cardiovascular effects produced by venom. However, prazosin significantly attenuated the pressor response produced by tentacle extract. Ketanserin (1 mg/kg, i.v.) did not have any significant effect on the cardiovascular response of the anaesthetised rat to venom (10 microg/kg, i.v.; 25+/-1 mmHg). Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) was performed to compare the two jellyfish samples used in the present study. In addition to ensuring reproducibility of future studies and allow comparison with previous research. We show, for the first time, that a pure venom sample extracted from C. fleckeri nematocysts and a tentacle extract have cardiovascular effects in the anaesthetised rat which are different and pharmacologically distinct.     

珍珠鸡胚胎发育的研究

本文是用肉眼和光镜研究珍珠鸡(Numlda m(?)lcagris)胚胎发育过程各阶段的形态学。珍珠鸡胚发育的规律、各器官结构形成的次序,均与鸡胚相似。胚胎在孵化的前10天增重较慢,平均每天约增重0.12g。孵化10天后,胚体重明显增快,平均每天约增重2.2g。胚体长度的变化与胚龄也有一定关系。根据珍珠鸡胚胎发育过程各阶段的形态学变化和胚重情况,可将胚胎发育过程大致分为前、中、后三期,这对孵化时的温度调节有重要参考意义。     

The in vivo cardiovascular effects of an Australasian box jellyfish (Chiropsalmus sp.) venom in rats.

Using a new technique to extract venom from the nematocysts of jellyfish, the in vivo cardiovascular effects of Chiropsalmus sp. venom were investigated in anaesthetized rats. Chiropsalmus sp. venom (150 microg/kg, i.v.) produced a transient hypertensive response (44+/-4 mmHg; n=6) followed by hypotension and cardiovascular collapse. Concurrent artificial respiration or pretreatment with Chironex fleckeri antivenom (AV, 3000 U/kg, i.v.) did not have any effect on the venom-induced hypertensive response nor the subsequent cardiovascular collapse. The cardiovascular response of animals receiving venom after the infusion of MgSO4 (50-70 mM @ 0.25 ml/min, i.v.; n=5) alone, or in combination with AV (n=5), was not significantly different from rats receiving venom alone. Prior administration of prazosin (50 microg/kg, i.v.; n=4) or ketanserin (1 mg/kg, i.v.; n=4) did not significantly attenuate the hypertensive response nor prevent the cardiovascular collapse induced by venom (50 microg/kg, i.v.). In contrast to previous work examining C. fleckeri venom, administration of AV alone, or in combination with MgSO4, was not effective in preventing cardiovascular collapse following the administration of Chiropsalmus sp. venom. This indicates that the venom of the two related box jellyfish contain different lethal components and highlights the importance of species identification prior to initiating treatment regimes following jellyfish envenoming.     

Cardiac effects of 1-alpha-acetylmethadol. IV. Mechanism of inotropic effects

1-α-Acetylmethadol (LAAM) and its major metabolites (1-α-acetylnormethadol and 1-α-acetyldinormethadol) produce a biphasic inotropic response in vitro in guinea pig atrium. Lower concentrations increase contractile height and higher concentrations decrease it. The positive inotropic response was blocked by dl-propranolol and attenuated by pretreatment of the animal with 6-OH-dopamine. These results indicate that endogenous norpinephrine mediates the positive inotropic response to LAAM and congeners. The narcotic agonist decreased the positive inotropic response to increasing concentrations of Ca²⁺. This finding suggests that LAAM decreases availability of extracellular Ca²⁺, thereby producing a negative inotropic response.     

Partial purification and characterization of a hemolysin (CAH1) from Hawaiian box jellyfish (Carybdea alata) venom.

We have isolated and characterized a novel hemolytic protein from the venom of the Hawaiian box jellyfish (Carybdea alata). Hemolysis of sheep red blood cells was used to quantitate hemolytic potency of crude venom extracted from isolated nematocysts and venom after fractionation and purification procedures. Hemolytic activity of crude venom was reduced or lost after exposure to the proteolytic enzymes trypsin, collagenase and papain. The activity exhibited lectin-like properties in that hemolysis was inhibited by D-lactulose and certain other sugars. Activity was irreversibly lost after dialysis of crude venom against divalent-free, 20mM EDTA buffer; it was optimal in the presence of 10mM Ca2+ or Mg2+. Two chromatographic purification methods, size fractionation on Sephadex G-200 and anion exchange with quaternary ammonium, provided fractions in which hemolytic activity corresponded to the presence of a protein band with an apparent molecular weight of 42kDa by SDS-PAGE. We have designated this protein as CAH1. The N-terminal sequence of CAH1 was determined to be: XAADAXSTDIDD/GIIG.