Differential roles of nitric oxide synthase isozymes in cardiotoxicity and mortality following chronic doxorubicin treatment in mice.
The roles of individual nitric oxide synthases (NOS) in anthracycline-related cardiotoxicity are not completely understood. We investigated the effects of a chronic treatment with doxorubicin (DOX) on knockouts of the individual NOS isozymes and on transgenic mice with myocardial overexpression of eNOS. Fractional shortening (FS) was reduced in untreated homozygous nNOS and iNOS knockouts as well as in eNOS transgenics. DOX-induced FS decrease in wild-type mice was attenuated only in eNOS knockouts, which were found to overexpress nNOS. No worsening of contractility was observed in DOX-treated eNOS transgenics and iNOS knockouts. Although the surviving DOX-treated nNOS knockouts exhibited no further impairment in contractility, most (70%) animals died within 7 weeks after treatment onset. In comparison to untreated wild-type hearts, the nitric oxide (NO) level was lower in hearts from DOX-treated wild-type mice and in all three untreated knockouts. DOX treatment had no effect on NO in the knockouts. These data indicate differential roles of the individual NOS in DOX-induced cardiotoxicity. Protection against DOX effects conferred by eNOS deletion may be mediated by a compensatory overexpression of nNOS. NOS inhibition-based prevention of anthracycline-induced cardiotoxicity should be eNOS-selective, simultaneously avoiding inhibiting nNOS.
Deng
Shiwei
S
Department of Pharmacology, Mainz University, Obere Zahlbacher Str. 67, 55131 Mainz, Germany.
Kruger
Anke
A
Schmidt
Albrecht
A
Metzger
Annegret
A
Yan
Tiandong
T
Gödtel-Armbrust
Ute
U
Hasenfuss
Gerd
G
Brunner
Friedrich
F
Wojnowski
Leszek
L
D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000008:administration & dosage / Q000633:toxicity*; D004195:Disease Models, Animal; D004317:Doxorubicin / Q000008:administration & dosage / Q000633:toxicity*; D006331:Heart Diseases / Q000139:chemically induced* / Q000401:mortality / Q000503:physiopathology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D009200:Myocardial Contraction / Q000187:drug effects; D009569:Nitric Oxide / Q000378:metabolism*; D052248:Nitric Oxide Synthase Type I / Q000235:genetics / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000235:genetics / Q000378:metabolism; D015996:Survival Rate
D000903:Antibiotics, Antineoplastic; D009569:Nitric Oxide; D004317:Doxorubicin; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III