Untitled - CNR

Marine research at CNRFigure 9: Histological section of a M. barbatus testis at stage IV (running).significantly either between sites or seasons,unlike GST, which appeared to be affectedby seasonality.A significant inhibition of cholinergic enzymeAChE was recorded in brain tissueof red mullets in site 3, with values around250 nmol/min/mg prot. AChE activityshowed no significant differences betweensites 1 and 2, where there have been similarvalues to those reported by Lionetto et al.[26] (70-130 nmol/min/mg prot) in harbourareas. More than organophosphate and carbamateinsecticides, the AChE can also beinhibited by heavy metals, which could explainthe values so high (almost twice) ofthis enzyme activity in site 3 highly industrializedand adjacent to the harbour of Milazzo.The results may suggest the exposureof red mullets to the AChE inhibitorcompounds in sediments in front of the refineryand the harbour area of Milazzo.Most studies on the aquatic environmenthave evaluated the content of specific endocrinedisruptors in surface waters [53,54], in effluents from sewage treatment ofcivilian discharges [55, 56] and industrialdischarges. Martin-Skilton et al. [14] investigatedgonadal changes caused by endocrinedisruption in M. barbatus in theNorth-West Mediterranean. These Authorsreported delayed gamete maturation, intersexualityand fibrosis in fish from a highlyimpacted area, near the city of Marseille.These phenomena were more evident duringthe reproductive period (spring). Inour study, however, although biomolecularanalysis revealed the induction of vitellogeningene in a single specimen from theMilazzo site, suggesting exposure to xenoestrogens,histology showed no pathologicalchanges of the gonads, such as fibrosisor feminization, or inhibition of gametematuration. Therefore, the reproductivepotential of these specimens was notaffected by exposure to contaminants. Histologicalanalysis of female gonads is currentlyunder way in order to validate furtherthe results obtained so far.2093