Main Title |
Tributyltin and Dexamethasone Induce Apoptosis in Rat Thymocytes by Mutually Antagonistic Mechanisms. |
Author |
Zucker, R. M. ;
Elstein, K. H. ;
Thomas, D. J. ;
Rogers, J. M. ;
|
CORP Author |
Health Effects Research Lab., Research Triangle Park, NC. ;ManTech Environmental Technology, Inc., Research Triangle Park, NC. |
Publisher |
cJul 94 |
Year Published |
1994 |
Report Number |
EPA/600/J-94/526; |
Stock Number |
PB95-148888 |
Additional Subjects |
Dexamethasone ;
Apoptosis ;
Thymus gland ;
Toxicology ;
Rats ;
Cultured cells ;
Dose-response relationships ;
Cell survival ;
Cycloheximide ;
Protein kinase C ;
Deoxyribonucleic acids ;
Reprints ;
Tri-n-butyltin methoxide ;
H 7
|
Holdings |
Library |
Call Number |
Additional Info |
Location |
Last Modified |
Checkout Status |
NTIS |
PB95-148888 |
Some EPA libraries have a fiche copy filed under the call number shown. |
|
07/26/2022 |
|
Collation |
10p |
Abstract |
We observed that rat thymocyte cultures exposed to 1.0 - 2.5 microM tri-n-butyltin methoxide (TBT) exhibited a rapid time- and concentration-dependent induction of apoptosis, with > 85% of cells exhibiting reduced DNA content within 1 hr after exposure to 2.0 - 2.5 microM TBT. Moreover, with continuous exposure to TBT, the DNA content of apoptotic nuclei increased with time, suggesting a reduced ability of DNA fragments to leave the nucleus of TBT-exposed cells following detergent-mediated cytolysis, possibly as a consequence of membrane/cytoplasm fixation. In contrast, exposure to 1.0 microM dexamethasone phosphate (DEX) resulted in a gradual time-dependent increase to approximately 45% induction of apoptosis by 6 hr (versus approximately 15% spontaneous induction in controls). However, simultaneous exposure to TBT and DEX resulted in a decreased response: TBT concentrations between 0.1 and 0.5 microM (which alone did not induce apoptosis) reduced the ability of DEX to induce apoptosis; at TBT concentrations greater than or equal to 1.0 microM, simultaneous exposure to DEX substantially decreased the extent of both TBT-induced cytotoxicity and apoptosis. Furthermore, while treatment with cycloheximide (CHX), a protein synthesis inhibitor, or H-7, a protein kinase C (PKC) inhibitor, completely blocked DEX-induced apoptosis, neither significantly reduced induction of apoptosis by TBT. |
Supplementary Notes |
Pub. in Toxicology and Applied Pharmacology, v127 n1 p163-170 Jul 94. See also PB92-164854. Prepared in cooperation with ManTech Environmental Technology, Inc., Research Triangle Park, NC. |
NTIS Title Notes |
Journal article. |
Title Annotations |
Reprint: Tributyltin and Dexamethasone Induce Apoptosis in Rat Thymocytes by Mutually Antagonistic Mechanisms. |
Category Codes |
57Y; 57F |
NTIS Prices |
PC A02/MF A01 |
Primary Description |
600/10 |
Document Type |
NT |
Cataloging Source |
NTIS/MT |
Control Number |
503415379 |
Origin |
NTIS |
Type |
CAT |