Mussels as sentinels of organotin pollution: Bioaccumulation and effects on P450-mediated aromatase activity

Citation

Morcillo Y, Albalat A & Porte C (1999) Mussels as sentinels of organotin pollution: Bioaccumulation and effects on P450-mediated aromatase activity. Environmental Toxicology and Chemistry, 18 (6), pp. 1203-1208. https://doi.org/10.1002/etc.5620180619

Abstract
Organotin pollution has been monitored in mollusks from the Catalan coast (Spain). Tributyltin (TBT) was the major compound detected, ranging from 200 to 1,100 ng/g wet weight as Sn. Tributyltin metabolites and triphenyltin (TPhT) were also detected, although to a lesser extent. Virtually organotin-free mollusks were obtained in the Alfacs Bay (Ebro Delta). Aromatase activity was determined in the digestive gland of a selected number of samples by measuring the tritiated water release from [1β-3H]-androstenedione. Enzyme activity was linear as a function of incubation time and protein content of the microsomal fraction. It was determined at a substrate concentration of 10 μM, and it exhibited a typical Michaelis-Menten kinetic, with an apparent constant, Km, of 32 ± 3 μM. Low aromatase activity (217-264 fmol/h/mg protein) was seen in mussels sampled in TBT-polluted environments compared with mussels from the virtually organotin-free point (345 fmol/h/mg protein). These results support the hypothesis of a TBT-mediated inhibition of cytochrome P450-aromatase activity in mussels, although no significant changes on tissue titers of testosterone/estradiol were observed.

Keywords
Organotin compounds; Mollusks; Biomonitoring; Aromatase activity

Journal
Environmental Toxicology and Chemistry: Volume 18, Issue 6