The effect of chronic nitric oxide synthases inhibition on regulatory proteins in rat hearts.
The aim of the present study was to characterize the effects of chronic nitric oxide synthase (NOS) inhibition on the alterations of regulatory myocardial proteins of intracellular signaling pathways (mitogen-activated protein kinase (MAPK) and Akt kinase cascades) and matrix metalloproteinases (MMP). Chronic NO deficiency (NOD) was induced by NG-nitro-L-arginine methyl ester (L-NAME, 40 mg/kg/day, 4 weeks). Protein levels and activation of protein kinases were determined using specific antibodies, activities of MMP were analyzed by zymography in gels containing gelatin as a substrate. The development of NOD was associated with decreased activation of endothelial NOS (eNOS) and down-regulation of protein level of inducible NOS (iNOS). Investigation of kinase pathways revealed that the activation of extracellular signal-regulated kinases (ERK) and the levels of upstream activators of ERK (aFGF, H-Ras) were decreased after L-NAME treatment. Western blot analysis revealed that chronic application of L-NAME also decreased the activation of Akt kinase as compared with control hearts. Study of MMPs showed that in L-NAME-treated rat hearts activities of tissue MMP-2 were decreased. It is concluded that development of NOD resulted in inhibition of ERK and Akt kinase pathways and these changes suggest the involvement of these cascades in responses of myocardium to NOD. The results also point to the possible relationship between ERK and Akt kinase pathways and activation of eNOS and/or MMP-2.
Spániková
Anna
A
Institute for Heart Research, Centre of Excellence for Cardiovascular Research, Slovak Academy of Sciences, Dúbravská cesta 9, P.O. Box 104, 840 05 Bratislava, Slovak Republic.
Simoncíková
Petra
P
Ravingerová
Tána
T
Pechánová
Olga
O
Barancík
Miroslav
M
D000818:Animals; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects*; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism*; D009206:Myocardium / Q000201:enzymology / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III; D051058:Oncogene Protein v-akt / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors
D004791:Enzyme Inhibitors; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; D019869:Phosphatidylinositol 3-Kinases; D051058:Oncogene Protein v-akt; D020929:Mitogen-Activated Protein Kinase Kinases; D020778:Matrix Metalloproteinase 2; C522363:Mmp2 protein, rat