title: The influence of the zona radiata on the toxicities of zinc, lead, mercury, copper and silver ions to embryos of steelhead trout Salmo gairdneri.
abstract: Eyed embryos of the steelhead trout (Salmo gairdneri) were significantly more resistant to zinc and lead but significantly less resistant to mercury, copper and silver if the zona radiata (egg capsule) was removed than if it was intact. The zona radiata appears to act as a cation exchanger and inhibits metals with high binding constants (Hg2+, Cu2+, Ag+) from entering the perivitelline fluid. Metals with low binding constants (Zn2+, Pb2+, Cd2+) rapidly penetrate the zona radiata and accumulate in the perivitelline fluid according to the Donnan equilibrium.
authors.forename: P J
authors.initials: PJ
authors.lastname: Rombough
mesh_terms: D000818:Animals; D003300:Copper / Q000633:toxicity; D004528:Egg Shell / Q000502:physiology; D005260:Female; D007854:Lead / Q000633:toxicity; D008628:Mercury / Q000633:toxicity; D008670:Metals / Q000633:toxicity*; D012487:Salmonidae / Q000196:embryology*; D012834:Silver / Q000633:toxicity; D014337:Trout / Q000196:embryology*; D015032:Zinc / Q000633:toxicity
chemical_list: D008670:Metals; D007854:Lead; D012834:Silver; D003300:Copper; D008628:Mercury; D015032:Zinc