Arsenobetaine and arsenocholine: Two marine arsenic compounds without embryotoxity

Abstract
The embryotoxicity of carboxymethyl(trimethyl)arsonium bromide [arsenobetaine,(CH3)3As+CH2COO] and of 2‐hydroxyethyl(trimethyl)arsonium bromide [arsenobetaine, (CH3)3As+CH2CH2OHBr] was explored. Sprague‐Dawley rat embryos with intact yolk sacs were removed on day 11 of gestation and grown in a culture medium for 24 h in the presence and absence of rat liver (S‐9) homogenate. Solutions of arsenobetaine or arsenocholine in dimethyl sulfoxide [DMSO, (CH3)2SO] (0.03 cm3) were added to the media to achieve concentrations of 20 m̈g arsenic compound per cm3 of medium. After 24 h the circulation and heart beat were monitored (indicator of embryolethality); in addition the crown‐to‐rump lengths were measured and the neural structures (somites) and limb buds observed (indicator of embryotoxicity). No evidence for embryotoxicity or embryolethality was found in the absence or the presence of S‐9. These results indicate that arsenobetaine, the most common arsenic compound found in seafood at concentrations from several micrograms to several hundred micrograms arsenic per gram, lacks subacute and acute prenatal toxicity.