title: Heavy metals affect nematocysts discharge response and biological activity of crude venom in the jellyfish Pelagia noctiluca (Cnidaria, Scyphozoa).
abstract: BACKGROUND
  Pollution of marine ecosystems and, specifically, heavy metals contamination may compromise the physiology of marine animals with events occurring on a cellular and molecular level. The present study focuses on the effect of short-term exposure to heavy metals like Zinc, Cadmium, Cobalt and Lanthanum (2-10 mM) on the homeostasis of Pelagia noctiluca (Cnidaria, Scyphozoa), a jellyfish abundant in the Mediterranean sea. This species possesses stinging organoids, termed nematocysts, whose discharge and concomitant delivery of venom underlie the survival of all Cnidaria.
  
  
  METHODS
  Nematocysts discharge response, elicited by combined chemico-physical stimulation, was verified on excised oral arms exposed to heavy metals for 20 min. In addition, the hemolytic activity of toxins, contained in the crude venom extracted from nematocysts isolated from oral arms, was tested on human erythrocytes, in the presence of heavy metals or their mixture.
  
  
  RESULTS
  Treatment with heavy metals significantly inhibited both nematocysts discharge response and hemolytic activity of crude venom, in a dose-dependent manner, not involving oxidative events, that was irreversible in the case of Lanthanum.
  
  
  CONCLUSIONS
  Our findings show that the homeostasis of Pelagia noctiluca, in terms of nematocysts discharge capability and effectiveness of venom toxins, is dramatically and rapidly compromised by heavy metals and confirm that this jellyfish is eligible as a model for ecotoxicological investigations.
authors.affiliation: Department of Human and Social Sciences, Messina, Italy.
authors.forename: Rossana
authors.initials: R
authors.lastname: Morabito
authors.forename: Silvia
authors.initials: S
authors.lastname: Dossena
authors.forename: Giuseppa
authors.initials: G
authors.lastname: La Spada
authors.forename: Angela
authors.initials: A
authors.lastname: Marino
mesh_terms: D000818:Animals; D003063:Cnidaria / Q000187:drug effects* / Q000378:metabolism; D003064:Cnidarian Venoms / Q000633:toxicity*; D006461:Hemolysis / Q000187:drug effects; D019216:Metals, Heavy / Q000494:pharmacology*; D058894:Nematocyst / Q000187:drug effects* / Q000378:metabolism
chemical_list: D003064:Cnidarian Venoms; D019216:Metals, Heavy