Abstract: A novel organoselenium compound, WB (1,2-[bis(1,2-benzisoselenazolone-3(2H)-ketone)]pentane) has indicated anti-tumor activity. Its pharmacokinetic data has never been determined. By using the H22 tumor bearing mouse model, the tissue distribution of WB after single and four consecutive doses (both were 120 mg/kg/d) was explored. The selenium content of the tissues was used as an indicator of WB absorption, distribution and metabolism. The selenium in the heart, liver, spleen, kidneys, lungs, stomach, pancreas, brain, colon, intestine, testes, plasma, and tumor were determined by generation atomic fluorescence spectrometry (AFS). With single or multiple oral administration of WB, the selenium content significantly increased in the liver, stomach, colon, and intestine. The selenium content in the spleen, lungs, pancreas, testes, plasma and tumor also increased compared with the controls; but no significant changes were found in the brain and kidney. WB and its metabolites distributed predominantly in the colon, liver, stomach and intestine, which resulted in a significant increase in the selenium content in both groups. There was no observed significant accumulation of WB in the vital organs.

Key words: Organoselenium compound, Antitumor, Tissue distribution, Hydride generation atomic fluorescence spectrometry