title: N-(2-mercaptoethyl)-1,3-propanediamine (WR-1065) protects thymocytes from programmed cell death.
abstract: Gamma-irradiation, glucocorticoid hormones, and calcium ionophores stimulate a suicide process in thymocytes, known as apoptosis or programmed cell death, that involves internucleosomal DNA fragmentation by a Ca(2+)- and Mg(2+)-dependent nuclear endonuclease. In this study we report that N-(2-mercaptoethyl)-1,3-propanediamine (WR-1065) blocked DNA fragmentation and cell death in thymocytes exposed to gamma-radiation, dexamethasone, or calcium ionophore A23187. WR-1065 protected the thymocytes from radiation-induced apoptosis when incubated with cells after irradiation but not before and/or during irradiation. WR-1065 inhibited Ca(2+)- and Mg(2+)-dependent DNA fragmentation in isolated thymocyte nuclei. Our results suggest that WR-1065 protects thymocytes from apoptosis by inhibiting Ca(2+)- and Mg(2+)-dependent nuclear endonuclease action.
authors.affiliation: Office of Chair of Science, Armed Forces Radiobiology Research Institute, Bethesda, MD 20889.
authors.forename: N
authors.initials: N
authors.lastname: Ramakrishnan
authors.forename: G N
authors.initials: GN
authors.lastname: Catravas
mesh_terms: D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects*; D004249:DNA Damage; D003907:Dexamethasone / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004720:Endonucleases / Q000378:metabolism; D005720:Gamma Rays; D008274:Magnesium / Q000378:metabolism; D008297:Male; D008624:Mercaptoethylamines / Q000494:pharmacology*; D051379:Mice; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects*; D013950:Thymus Gland / Q000166:cytology* / Q000187:drug effects / Q000528:radiation effects
chemical_list: D008624:Mercaptoethylamines; C020174:N-(2-mercaptoethyl)-1,3-diaminopropane; D000001:Calcimycin; D003907:Dexamethasone; D004720:Endonucleases; D008274:Magnesium; D002118:Calcium