Response of fish immune cells to in vitro organotin exposures

Effect of in vitro and in vivo organotin exposures on the immune functions of murray cod (Maccullochella peelii peelii)

“…This effect was an expected result from in vivo DBT exposure, as the literature agrees that DBT is a potent thymolytic compound that reduces the number of T-lymphocytes in test animals [34]. Previous experiments have also found that DBT is more effective at killing lymphocytes than TBT [23,34]. In this in vivo study, TBT also reduced the number of lymphocytes but only at the highest exposure of 2.5 mg/ kg, which indicates that DBT is the more potent immunosuppressant.…”

“…Numerous studies have reported TBT and DBT as immunotoxins in fish, and our group has previously reported organotininduced immunotoxicity in rainbow trout and in the Australian freshwater native silver perch (Bidyanus bidyanus) [23]. In vitro studies using isolated spleen and head kidney cells from juvenile rainbow trout showed that TBT and DBT suppressed mitogen-stimulated lymphoproliferation at concentrations Ն50 g/L.…”

“…To obtain serum, the blood was placed in microfuge tubes and centrifuged at 800 g for 15 min at 4ЊC. The head kidney cells were isolated using the method previously described by O'Halloran et al [23]. Briefly, cells were disrupted from the head kidney tissue and passed through a 250-m nylon mesh.…”

“…Previous reports from our group have shown that in vitro doses of TBT and DBT reduced the PHA-stimulated proliferation of head kidney lymphocytes isolated from both rainbow trout and silver perch [10,23].…”

“…In vitro studies using isolated spleen and head kidney cells from juvenile rainbow trout showed that TBT and DBT suppressed mitogen-stimulated lymphoproliferation at concentrations Ն50 g/L. The results also indicated that DBT was the more potent immunosuppressant [23]. Furthermore, extensive in vitro studies have reported that TBT can either suppress or increase the phagocytic activity (i.e., chemiluminescence) of oyster toadfish (Opsanus tau) macrophages, depending on the dose given [24,25].…”