Silver nanoparticles and silver ions indistinguishably decrease sperm
motility in Pacific oysters (Magallana gigas) after short-term direct
exposure
Fátima Fernández-García, Ana Carvalhais, Ana Marques, Isabel B. Oliveira, Sofia Guilherme, Helena Oliveira, Catarina C V Oliveira, Elsa Cabrita, Juan F. Asturiano, Mário Pacheco, Cláudia Mieiro
Abstract
The present study aimed to evaluate the reprotoxicity of environmental
(0.25 μg.L-1) and supra-environmental (25 μg.L-1 and 250
μg.L-1) levels of silver nanoparticles (Ag NP) on the Pacific oyster
(Magallana gigas), by determining
sperm quality. For that, we evaluated sperm motility, mitochondrial function
and oxidative stress. To determine whether the Ag toxicity was related to the
NP or its dissociation into Ag ions (Ag+), we tested the same
concentrations of Ag+. We observed no dose-dependent responses for
Ag NP and Ag+, and both impaired sperm motility indistinctly without
affecting mitochondrial function or inducing membrane damage. We hypothesize that the toxicity of Ag NP is mainly due to adhesion to the sperm
membrane. Blockade of membrane ion channels may also be a mechanism by which Ag
NP and Ag+ induce toxicity. The presence of Ag in the marine
ecosystem is of environmental concern as it may affect reproduction in oysters.
Environmental Toxicology and Pharmacology