Open AccessL‐Methionine Induces Stage‐Dependent Changes of Differentiation and Oxidative Activity in Sea Urchin Embryogenesis
Author(s) -
Pagano Giovanni,
Bonassi Stefano,
Biase Antonella De,
Degan Paolo,
Deeva Irina B.,
Doronin Yuri K.,
Iaccarino Mario,
Oral Rahime,
Warnau Michel,
Korkina Ludmila G.
Publication year - 1997
Publication title -
pharmacology & toxicology
Language(s) - English
Resource type - Journals
eISSN - 1600-0773
pISSN - 0901-9928
DOI - 10.1111/j.1600-0773.1997.tb00043.x
Subject(s) - methionine , fertilisation , embryogenesis , developmental toxicity , reactive oxygen species , biology , andrology , embryo , sea urchin , biochemistry , chemistry , genetics , microbiology and biotechnology , pregnancy , fetus , amino acid , medicine , reproductive technology
This study was to investigate developmental toxicity of some selected low molecular weight antioxidants, by utilising sea urchin embryos and gametes as model system. Sea urchin embryos or sperm were exposed at different developmental stages to L‐methionine or some selected low molecular weight antioxidants: a) N‐acetylcysteine; b) L‐carnosine; c) L‐homocarnosine, and d) L‐anserine. L‐methionine displayed developmental toxicity at levels ≥10 −5 M, whereas the other agents tested were mostly active at levels ≥10 −4 M. When embryos were exposed to 10 −4 M L‐methionine or N‐acetylcysteine at different developmental stages, the most severe effects were exerted by early exposures (0 to 2 hr after fertilisation), whereas later exposures turned to lesser or no effects. Cytogenetic analysis of L‐methionine‐exposed embryos showed a significant mitogenic effect and increase of mitotic aberrations. Fertilisation success was decreased by L‐methionine (10 −6 M to 10 −3 M) added at the moment of fertilisation, with increasing developmental and cytogenetic abnormalities in the offspring. The formation of reactive oxygen species in embryos and gametes was determined by: a) analysing the DNA oxidative product, 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG), and b) luminol‐dependent chemiluminescence. The results showed that: 1) 8‐OHdG levels were increased during embryogenesis; 2) fertilisation was associated with a double‐wave luminol‐dependent chemiluminescence emission; 3) luminol‐dependent chemiluminescence was maximal in cleavage, declining down to zero in plutei, and 4) an embryotoxic L‐methionine or N‐acetylcysteine level (10 −4 M) turned to a decrease in reactive oxygen species formation. The data suggest that L‐methionine‐ or N‐acetylcysteine‐induced developmental toxicity is confined to early stages. A role for oxidative activity is suggested in modulating cell differentiation and embryogenesis, consistent with antioxidant‐induced damage to early life stages.