In vitro effects of triphenyltin acetate (TPTA) on mouse lymphocyte proliferation

Organotin compounds (Ors) are used worldwide in industry and in agricultura l practice. In Italy, the OT mostly used is the fungicide triphenyltin acet ate (TPTA), although in past years it has been submitted to revision for oc cupational and environmental grounds. In the present study, the possible ef fect of the fungicide on cell proliferation has been investigated, using [H -3]thymidine incorporation radiometric assay. Mouse thymocytes in primary c ulture were stimulated for 24 h with T- and B-cell mitogens (concanavalin A , CON A and phytohemagglutinin, PHA or pokeweed mitogen, PWM, respectively) . Cultures were then exposed 24 h to 0, 1 and 8 muM TPTA. At the end of inc ubation, cells were pulsed with methyl-[H-3]thymidine and harvested for tot al radioactivity counts after a further 24 h of incubation. An overall dose -dependent significant (P < 0.05) reduction of proliferative response was o bserved with all mitogens tested. Interestingly, CON A proved to be more se nsitive (P < 0.05) to the TPTA toxic effect compared with PWM and PHA. TPTA is cytotoxic to mouse thymocytes in primary culture, particularly towards the mature lymphocytes (CD4(+) and CD8(+)). The present results support the hypothesis of a TPTA-induced decrease of lymphoproliferative response to T - and B-cell mitogens, previously observed with other (C) 2001 Elsevier Sci ence Ltd. All rights reserved.