The effects of a purified toxic extract of Prymnesium patelliferum on transport of ions through the plasma membrane of synaptosomes

Meldahl, Anne‐Sophie; Fonnum, Frode

doi:10.1016/0041-0101(95)00038-n

Cited by 11 publications

(6 citation statements)

References 35 publications

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“…Cultures of both P. parvum and P. patelliferum were toxic to Artemia, and crude lipid extracts had toxic effects on human erythrocytes and synaptic vesicles of rat brains (Meldahl et al, 1994). An extract of P. patelliferum has been shown to have two different effects on the transport of neurotransmitters across nerve membranes: (1) it inhibits the sodium-dependent uptake of L-glutamate and GABA (γ-aminobutyric acid), and (2) it enhances the calcium-dependent release of acetylcholine (Meldahl and Fonnum, 1995). An extract of P. patelliferum at a concentration of 5 × 10 4 cells/ml caused a rapid inhibition of glutamate accumulation in the synaptosomes.…”

Section: A Chrysochromulina Sppmentioning

confidence: 98%

“…An extract of P. patelliferum at a concentration of 5 × 10 4 cells/ml caused a rapid inhibition of glutamate accumulation in the synaptosomes. The effect on this transport system is probably due to impairment of one or more gradients (sodium, potassium, and calcium) and depolarization of the plasma membrane (Meldahl et al, 1994(Meldahl et al, , 1995. The toxic extract of P. patelliferum increases the permeability of synaptosomes to Ca 2+ , Na + , and K + , and this effect may be responsible for the plasma membrane depolarization and the disturbance of neurotransmitter processes (Meldahl and Fonnum, 1995).…”

Section: A Chrysochromulina Sppmentioning

confidence: 99%

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The Effects of Harmful Algal Blooms on Aquatic Organisms

Landsberg

2002

Reviews in Fisheries Science

1,135

807

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Section: A Chrysochromulina Sppmentioning

confidence: 98%

Section: A Chrysochromulina Sppmentioning

confidence: 99%

The Effects of Harmful Algal Blooms on Aquatic Organisms

Landsberg

2002

Reviews in Fisheries Science

1,135

807

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“…For example, Meldahl & Fonnum (1995) studied how purified toxin extracted from P. patelliferum affects rat brain synaptosomes. They found that the algal extract increased the permeability to Na + , Ca + and K + in the synaptosomal membrane and that membrane depolarization and inhibition of the net uptake of L-glutamate also occurred.…”

Section: Activity and Survival Of Copepodsmentioning

confidence: 99%

Toxic haptophyte Prymnesium parvum affects grazing, survival, egestion and egg production of the calanoid copepods Eurytemora affinis and Acartia bifilosa

Sopanen¹,

Koski²,

Kuuppo³

et al. 2006

Mar. Ecol. Prog. Ser.

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Nitrogen-and phosphorus-depleted or NP-balanced toxic haptophyte Prymnesium parvum was fed to 2 dominant copepod species of the northern Baltic Sea (Eurytemora affinis and Acartia bifilosa), and their ingestion, egg and faecal pellet production rates and mortality were measured. The copepods were incubated in 5 different cell concentrations of P. parvum for 3 consecutive days; the cryptophyte Rhodomonas salina was used as a control for non-toxic, nutritionally high-quality food. Toxicity (haemolytic activity) of P. parvum was measured before and after the incubations. The haemolytic activity of P. parvum was the highest in cultures grown under nutrient deficiency. The toxicity decreased after 1 d incubation in all treatments, in both the presence and absence of copepods. Neither of the copepod species ingested P. parvum, irrespective of the nutrient treatment (toxicity) or cell concentration, and the pellet and egg production rates were correspondingly low. Although there was no significant increase in mortality in P. parvum treatments, copepods that were exposed to P. parvum in any concentration or nutrient treatment soon became inactive. It was evident that the toxicity of even nutrient-replete P. parvum had an indirect and sublethal influence on copepods, although this could not be measured as short-term increased mortality. Our results suggest a strong reduction in secondary production of copepods in an event of a P. parvum bloom.

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“…Glutamate uptake in synaptosomes is dependent on the electrochemical gradient of Na + and K + generated by the Na + /K + -ATPase (Danbolt, 2001). Meldahl and Fonnum (1995) suggested that the prymnesium toxin induces a nonselective Na + influx, diminishing the driving force for uptake. They also showed that the toxin increases the Ca 2+ and Na + influx, through the plasma membrane of synaptosomes.…”

Section: Discussionmentioning

confidence: 99%

A TOXIC EXTRACT OF THE MARINE PHYTOFLAGELLATEPRYMNESIUM PARVUMINDUCES CALCIUM-DEPENDENT RELEASE OF GLUTAMATE FROM RAT BRAIN SYNAPTOSOMES

Mariussen

Nelson

Fonnum

2005

Journal of Toxicology and Environmental Health, Part A

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Blooms of the marine phytoflagellate Prymnesium parvum produced mass mortality of fish in Norway and many other parts of the world. The effects of a purified algae extract of P. parvum on transmitter release from rat brain synaptosomes were studied to characterize its toxic action. Synaptosomes are detached nerve terminals and represent a simple system that has retained the machinery for uptake, synthesis, storage, and release of neurotransmitters. A crude methanol extract of P. parvum was purified by reverse-phase column for fast protein liquid chromatography (FPLC). The purified extract stimulated Ca2+-dependent spontaneous release of glutamate in a concentration-dependent manner. The release was increased by addition of extracellular Ca2+. The release of glutamate was suppressed by the Ca2+-channel blockers flunarizine (10 microM), diltiazem (10 microM), and verapamil (10 microM). The stimulation of release of glutamate from rat brain synaptosomes induced by the toxin may be due to an ionophorelike property of the algae extract such as previously reported for the potent algal toxin maitotoxin. At high concentrations the toxin primarily acts as a powerful lytic agent.

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The effects of a purified toxic extract of Prymnesium patelliferum on transport of ions through the plasma membrane of synaptosomes

Cited by 11 publications

References 35 publications

The Effects of Harmful Algal Blooms on Aquatic Organisms

The Effects of Harmful Algal Blooms on Aquatic Organisms

Toxic haptophyte Prymnesium parvum affects grazing, survival, egestion and egg production of the calanoid copepods Eurytemora affinis and Acartia bifilosa

A TOXIC EXTRACT OF THE MARINE PHYTOFLAGELLATEPRYMNESIUM PARVUMINDUCES CALCIUM-DEPENDENT RELEASE OF GLUTAMATE FROM RAT BRAIN SYNAPTOSOMES

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