Abstract
Adriamycin (or doxorubicin) is an active and broad spectrum chemotherapeutic agent. Unfortunately, its clinical use is severely restricted by a dose-limiting cardiotoxicity which has been linked to the formation of superoxide. Enzymatic one-electron reduction of adriamycin forms adriamycin semiquinone radical, which rapidly reacts with oxygen to form superoxide and adriamycin. In this way, adriamycin provides a kinetic mechanism for the one-electron reduction of oxygen by flavoenzymes such as NADPH-cytochrome P450 reductase and mitochondrial NADH dehydrogenase. We demonstrate here that the endothelial isoform of nitric oxide synthase (eNOS) reduces adriamycin to the semiquinone radical. As a consequence, superoxide formation is enhanced and nitric oxide production is decreased. Adriamycin binds to eNOS with a K(m) of approximately 5 μM, as calculated from both eNOS-dependent NADPH consumption and superoxide generation. Adriamycin stimulated superoxide formation is not affected by calcium/calmodulin and is abolished by the flavoenzyme inhibitor, diphenyleneiodonium. This strongly suggests that adriamycin undergoes reduction at the reductase domain of eNOS. A consequence of eNOS-mediated reductive activation of adriamycin is the disruption of the balance between nitric oxide and superoxide. This may lead eNOS to generate peroxynitrite and hydrogen peroxide, potent oxidants implicated in several vascular pathologies.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 11293-11297 |
| Number of pages | 5 |
| Journal | Biochemistry |
| Volume | 36 |
| Issue number | 38 |
| DOIs | |
| State | Published - Sep 23 1997 |
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ASJC Scopus subject areas
- Biochemistry
Cite this
Endothelial nitric oxide synthase-dependent superoxide generation from adriamycin. / Vásquez-Vivar, Jeannette; Martasek, Pavel; Hogg, Neil; Masters, Bettie Sue Siler; Pritchard, Kirkwood A.; Kalyanaraman, B.
In: Biochemistry, Vol. 36, No. 38, 23.09.1997, p. 11293-11297.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Endothelial nitric oxide synthase-dependent superoxide generation from adriamycin
AU - Vásquez-Vivar, Jeannette
AU - Martasek, Pavel
AU - Hogg, Neil
AU - Masters, Bettie Sue Siler
AU - Pritchard, Kirkwood A.
AU - Kalyanaraman, B.
PY - 1997/9/23
Y1 - 1997/9/23
N2 - Adriamycin (or doxorubicin) is an active and broad spectrum chemotherapeutic agent. Unfortunately, its clinical use is severely restricted by a dose-limiting cardiotoxicity which has been linked to the formation of superoxide. Enzymatic one-electron reduction of adriamycin forms adriamycin semiquinone radical, which rapidly reacts with oxygen to form superoxide and adriamycin. In this way, adriamycin provides a kinetic mechanism for the one-electron reduction of oxygen by flavoenzymes such as NADPH-cytochrome P450 reductase and mitochondrial NADH dehydrogenase. We demonstrate here that the endothelial isoform of nitric oxide synthase (eNOS) reduces adriamycin to the semiquinone radical. As a consequence, superoxide formation is enhanced and nitric oxide production is decreased. Adriamycin binds to eNOS with a K(m) of approximately 5 μM, as calculated from both eNOS-dependent NADPH consumption and superoxide generation. Adriamycin stimulated superoxide formation is not affected by calcium/calmodulin and is abolished by the flavoenzyme inhibitor, diphenyleneiodonium. This strongly suggests that adriamycin undergoes reduction at the reductase domain of eNOS. A consequence of eNOS-mediated reductive activation of adriamycin is the disruption of the balance between nitric oxide and superoxide. This may lead eNOS to generate peroxynitrite and hydrogen peroxide, potent oxidants implicated in several vascular pathologies.
AB - Adriamycin (or doxorubicin) is an active and broad spectrum chemotherapeutic agent. Unfortunately, its clinical use is severely restricted by a dose-limiting cardiotoxicity which has been linked to the formation of superoxide. Enzymatic one-electron reduction of adriamycin forms adriamycin semiquinone radical, which rapidly reacts with oxygen to form superoxide and adriamycin. In this way, adriamycin provides a kinetic mechanism for the one-electron reduction of oxygen by flavoenzymes such as NADPH-cytochrome P450 reductase and mitochondrial NADH dehydrogenase. We demonstrate here that the endothelial isoform of nitric oxide synthase (eNOS) reduces adriamycin to the semiquinone radical. As a consequence, superoxide formation is enhanced and nitric oxide production is decreased. Adriamycin binds to eNOS with a K(m) of approximately 5 μM, as calculated from both eNOS-dependent NADPH consumption and superoxide generation. Adriamycin stimulated superoxide formation is not affected by calcium/calmodulin and is abolished by the flavoenzyme inhibitor, diphenyleneiodonium. This strongly suggests that adriamycin undergoes reduction at the reductase domain of eNOS. A consequence of eNOS-mediated reductive activation of adriamycin is the disruption of the balance between nitric oxide and superoxide. This may lead eNOS to generate peroxynitrite and hydrogen peroxide, potent oxidants implicated in several vascular pathologies.
UR - http://www.scopus.com/inward/record.url?scp=19244383998&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=19244383998&partnerID=8YFLogxK
U2 - 10.1021/bi971475e
DO - 10.1021/bi971475e
M3 - Article
C2 - 9333325
AN - SCOPUS:19244383998
VL - 36
SP - 11293
EP - 11297
JO - Biochemistry
JF - Biochemistry
SN - 0006-2960
IS - 38
ER -