title: 2'-deoxyadenosine induces apoptosis in rat chromaffin cells.
abstract: We show here that 2'-deoxyadenosine (2'-dAdo) but not adenosine was toxic to chromaffin cells of 3-4-week-old rat adrenal glands. More than 75% of the cells plated in culture gradually died over a 3-day period in the presence of 100 microM 2'-dAdo plus 3 microM deoxycoformycin (DCF). Morphological observations together with bisbenzimide staining and terminal deoxynucleotidyl transferase-mediated nick and labeling showed membrane blebbing, shrinkage of cell bodies, chromatin condensation, and DNA fragmentation, suggesting apoptosis-like cell death by 2'-dAdo. Lethal effects of 2'-dAdo were potentiated by DCF, a drug that inhibits adenosine deaminase. 2'-dAdo-prompted cell death was not prevented by inhibitors of nucleoside transporter (3 microM dilazep or 1 microM nitrobenzylthioinosine), precursors of pyrimidine nucleotide biosynthesis (300 microM uridine or 100 microM 2'-deoxycytidine), or 5 mM nicotinamide. Cells incubated with 2'-dAdo (100 and 300 microM) showed a three- and ninefold, respectively, increase in content of dATP, a product known to be an inhibitor of ribonucleotide reductase, an enzyme essential for DNA synthesis. Formation of dATP was completely prevented by iodotubercidin (ITu), a drug that inhibits phosphorylation of 2'-dAdo to dATP by nucleoside kinase. It is interesting that nanomolar concentrations of ITu also completely protected chromaffin cells from 2'-dAdo lethality. Our study demonstrates for the first time that mammalian adrenal chromaffin cells undergo apoptotic cell death by a natural nucleoside and suggests that this model could be used to study apoptosis and cell function.
authors.affiliation: Department of Pharmacology, School of Medicine, Wayne State University, Detroit, Michigan 48201, USA.
authors.forename: A R
authors.initials: AR
authors.lastname: Wakade
authors.forename: X
authors.initials: X
authors.lastname: Guo
authors.forename: K C
authors.initials: KC
authors.lastname: Palmer
authors.forename: J S
authors.initials: JS
authors.lastname: Kulkarni
authors.forename: D A
authors.initials: DA
authors.lastname: Przywara
authors.forename: T D
authors.initials: TD
authors.lastname: Wakade
mesh_terms: D000241:Adenosine / Q000378:metabolism / Q000494:pharmacology; D000243:Adenosine Deaminase / Q000502:physiology; D000255:Adenosine Triphosphate / Q000378:metabolism; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D019439:Chromaffin Cells / Q000166:cytology* / Q000201:enzymology; D003839:Deoxyadenosines / Q000378:metabolism / Q000633:toxicity*; D004109:Dilazep / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004837:Epinephrine / Q000502:physiology; D009153:Mutagens / Q000633:toxicity*; D009638:Norepinephrine / Q000502:physiology; D010766:Phosphorylation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012680:Sensitivity and Specificity; D013868:Thioinosine / Q000031:analogs & derivatives / Q000494:pharmacology; D014372:Tubercidin / Q000031:analogs & derivatives / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D000316:Adrenergic alpha-Agonists; D003839:Deoxyadenosines; D004791:Enzyme Inhibitors; D009153:Mutagens; D014665:Vasodilator Agents; C034214:5-iodotubercidin; D013868:Thioinosine; D000255:Adenosine Triphosphate; D000243:Adenosine Deaminase; D004109:Dilazep; C001789:4-nitrobenzylthioinosine; D000241:Adenosine; D014372:Tubercidin; C058118:2'-deoxyadenosine; D009638:Norepinephrine; D004837:Epinephrine