Comparative toxicity of alkyltin and estertin stabilizers.

Area of Science:

• Toxicology
• Organotin compounds
• Biochemistry

Background:

• Organotin compounds exhibit diverse toxicological profiles.
• Esterin organotins (CBETC, CMETC) and their hydrolysis product (CETC) were compared to dialkyltins (DBTC, DOTC).
• Understanding differential toxicity is crucial for risk assessment.

Purpose of the Study:

• To compare the oral and parenteral toxicities of estertin and dialkyltin compounds in rats.
• To investigate the in vitro lymphocytotoxic effects of these compounds.
• To elucidate the mechanisms underlying observed toxicity differences.

Main Methods:

• 2-week feeding studies with varying dietary concentrations of CBETC, CMETC, CETC, DBTC, and DOTC.
• Parenteral administration (intraperitoneal/intravenous) of selected compounds.
• In vitro studies assessing lymphocyte metabolism, viability, and blast transformation.

Main Results:

• Esterins (CBETC, CMETC) caused growth retardation and organ weight changes only at high doses (1350 ppm), with CETC showing no toxicity.
• Dialkyltins (DBTC, DOTC) induced decreased body weight gain and significant lymphoid organ atrophy (thymus, spleen) at lower doses (50-150 ppm).
• In vitro, all compounds showed dose-dependent lymphocyte stimulation, but esterins were less potent than dialkyltins at higher concentrations.

Conclusions:

• Hydrolysis of estertins to CETC in vivo may explain their lower systemic toxicity compared to dialkyltins.
• Dialkyltins exhibit significant in vivo and in vitro lymphocytotoxicity, leading to lymphoid atrophy.
• The findings highlight the importance of metabolic activation and detoxification pathways in determining organotin toxicity.