Acute toxicity and metabolism of arsenocholine in mice

The acute toxicity of arsenocholine was examined in mice by oral administration and intravenous injection. The LD50 values of arsenocholine were 6.5 g kg−1 for oral administration and 187 mg kg−1 for oral administration and 187 mg kg−1 for intravenous injection. Decreases of respiration and spontaneous motility were observed in the mice dosed orally at 12 g kg−1. The animals exhibited ataxia and finally showed paralysis of the hind legs within 20 min of administration. When arsenocholine was administered orally to mice at 5 or 50 mg As kg−1, the greater part of the arsenic administered was recovered in urine within 96 h. The metabolite of arsenocholine in urine was identified as arsenobetaine by high‐performance liquid chromatography‐inductively coupled plasma emission spectrometry (HPLC ICP) and fast atom bombardment mass spectrometry (FAB MS). These results suggested that the major part of orally administered arsenocholine was absorbed from the gastrointestinal tract in mice and then rapidly excreted in urine with biotransformation.