KMUP-1 attenuates isoprenaline-induced cardiac hypertrophy in rats through NO/cGMP/PKG and ERK1/2/calcineurin A pathways.
OBJECTIVE
To determine whether KMUP-1, a novel xanthine-based derivative, attenuates isoprenaline (ISO)-induced cardiac hypertrophy in rats, and if so, whether the anti-hypertrophic effect is mediated by the nitric oxide (NO) pathway.


METHODS
In vivo, cardiac hypertrophy was induced by injection of ISO (5 mg.kg(-1).day(-1), s.c.) for 10 days in Wistar rats. In the treatment group, KMUP-1 was administered 1 h before ISO. After 10 days, effects of KMUP-1 on survival, cardiac hypertrophy and fibrosis, the NO/guanosine 3'5'-cyclic monophosphate (cGMP)/protein kinase G (PKG) and hypertrophy signalling pathways [calcineurin A and extracellular signal-regulated kinase (ERK)1/2] were examined. To investigate the role of nitric oxide synthase (NOS) in the effects of KMUP-1, a NOS inhibitor, N(omega)-nitro-L-arginine (L-NNA) was co-administered with KMUP-1. In vitro, anti-hypertrophic effects of KMUP-1 were studied in ISO-induced hypertrophic neonatal rat cardiomyocytes.


RESULTS
In vivo, KMUP-1 pretreatment attenuated the cardiac hypertrophy and fibrosis and improved the survival of ISO-treated rats. Plasma NOx (nitrite and nitrate) and cardiac endothelial NOS, cGMP and PKG were all increased by KMUP-1. The activation of hypertrophic signalling by calcineurin A and ERK1/2 in ISO-treated rats was also attenuated by KMUP-1. All these effects of KMUP-1 were inhibited by simultaneous administration of L-NNA. Similarly, in vitro, KMUP-1 attenuated hypertrophic responses and signalling induced by ISO in neonatal rat cardiomyocytes.


CONCLUSIONS
KMUP-1 attenuates the cardiac hypertrophy in rats induced by administration of ISO. These effects are mediated, at least in part, by NOS activation. This novel agent, which targets the NO/cGMP pathway, has a potential role in the prevention of cardiac hypertrophy.
Department and Graduate Institute of Pharmacology, Kaohsiung Medical University, Taiwan.
Jwu-Lai
JL
Yeh
Jong-Hau
JH
Hsu
Ping-Ju
PJ
Wu
Shu-Fen
SF
Liou
Chung-Pin
CP
Liu
Ing-Jun
IJ
Chen
Bin-Nan
BN
Wu
Zen-Kong
ZK
Dai
Jiunn-Ren
JR
Wu
D000818:Animals; D019703:Calcineurin / Q000378:metabolism; D006332:Cardiomegaly / Q000401:mortality / Q000517:prevention & control*; D006152:Cyclic GMP / Q000378:metabolism; D017869:Cyclic GMP-Dependent Protein Kinases / Q000378:metabolism; D004195:Disease Models, Animal; D016503:Drug Delivery Systems; D005355:Fibrosis; D007545:Isoproterenol / Q000633:toxicity; D008297:Male; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000187:drug effects* / Q000378:metabolism; D010880:Piperidines / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000187:drug effects; D015996:Survival Rate; D014970:Xanthines / Q000494:pharmacology*
D010880:Piperidines; D014970:Xanthines; C439304:KMUP 1; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D017869:Cyclic GMP-Dependent Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D019703:Calcineurin; D006152:Cyclic GMP; D007545:Isoproterenol