Investigation of EROD, CYP1A immunopositive proteins and SOD in haemocytes of Chamelea gallina and their role in response to B[a]P

CYP1A subfamily represents the main form of Cytochrome P450 involved in B[a]P detoxification, but there are no clear evidences about its presence in invertebrates. EROD activity is strictly related to CYP1A presence, at the same time P450-dependent oxidative metabolism leads to ROS production, thought to be an important mechanism of pollutant-mediated toxicity in aquatic organisms. SODs, EROD and CYP1A activities and/or expressions were detected in pooled clams haemocytes and cell-free haemolymph after 24h, 7 and 12 days of exposure to 0.5 mg/L of B[a]P. After 24 hours, B[a]P content was maximum in whole tissues. A 61kDa band was recognized in haemocytes and cell-free haemolymph by polyclonal anti-fish CYP1A, while 53.5 and 63.8 kDa CYP1A immunopositive-proteins were discriminate without differences of expression. Differently, EROD, MnSOD activity/expression and ECSOD expression decreased in haemocytes and haemolymph. C. gallina immune system presents an interesting response dose/time exposure of B[a]P and the 7 days condition highlights the major effects of xenobiotic action. The identification of basal EROD levels supports the possible presence of the CYP1A, never identified in C. gallina and more specifically never isolated in immune cells, as confirmed by CYP1A-immunopositive proteins identification.