Tri-n-butyltin-induced cytotoxicity on rat thymocytes in presence and absence of serum.
Influence of fetal bovine serum (FBS) on cytotoxicity induced by tri-n-butyltin (TBT), an environmental pollutant, on rat thymocytes was examined to reveal how FBS modifies TBT cytotoxicity. As the medium FBS concentration was increased from 0 to 10%, the cytotoxicity of TBT was dose-dependently reduced when the cells were incubated with 1 microM TBT for 3 h. Almost complete inhibitions of TBT-induced changes in cell viability and population of cells with exposed phosphatidylserine (cells undergoing apoptosis) were observed when the FBS concentration was 10%. Thus, the cytotoxicity induced by 3 h incubation with TBT in FBS-free medium may be different from that in medium containing 10% FBS. However, even in presence of 10% FBS, TBT at concentrations ranging from 10 to 300 nM exerted cytotoxic action on rat thymocytes when the cells were incubated with TBT for 24 h. TBT dose-dependently increased the population of shrunken cells, of which more than 30% were stained with propidium. TBT at 30 nM or more significantly increased the population of cells with hypodiploid DNA, indicating TBT-induced apoptotic cell death. Thus, in the presence of 10% FBS, the prolonged incubation (24 h) of rat thymocytes with TBT at nanomolar concentrations induced apoptosis rather than necrosis.
Umebayashi
C
C
Laboratory of Cell Signaling, Faculty of Integrated Arts and Sciences, The University of Tokushima, 770-8502, Japan.
Oyama
Y
Y
Chikahisa-Muramastu
L
L
Nakao
H
H
Nishizaki
Y
Y
Nakata
M
M
Soeda
F
F
Takahama
K
K
D000818:Animals; D017304:Annexin A5; D017209:Apoptosis / Q000187:drug effects; D002417:Cattle; D002452:Cell Count / Q000379:methods; D048430:Cell Shape / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects*; D016895:Culture Media, Serum-Free / Q000494:pharmacology*; D003581:Cytodiagnosis / Q000379:methods; D004171:Diploidy; D004305:Dose-Response Relationship, Drug; D011419:Propidium; D051381:Rats; D017208:Rats, Wistar; D012710:Serum Albumin, Bovine / Q000494:pharmacology*; D013950:Thymus Gland / Q000737:chemistry / Q000166:cytology / Q000187:drug effects*; D013997:Time Factors; D014220:Trialkyltin Compounds / Q000009:adverse effects* / Q000037:antagonists & inhibitors
D017304:Annexin A5; D016895:Culture Media, Serum-Free; D014220:Trialkyltin Compounds; D012710:Serum Albumin, Bovine; D011419:Propidium; C011559:tributyltin