[Influence of nitric oxide on the angiotensin II-activated protein kinase C activity in cultured neonatal rat cardiomycytes].
We examined the effect of endogenous and exogenous nitric oxide (NO) on protein kinase C (PKC) activity induced by angiotensin II (Ang II) in cultured neonatal rat cardiomyocytes. The results are as follows. The activity of PKC was increased by Ang II (0.01-10 micromol/L) in a dose-dependent manner, but decreased by NO precursor L-arginine (L-Arg) (10 micromol/L-10 mmol/L) in a dose-dependent manner in cultured neonatal rat cardiomyocytes. Pretreatment with L-Arg (100 micromol/L) decreased significantly Ang II -activated PKC activity and PKC activity induced by phorbol 12-myristate 13-acetate (PMA) ( 10 micromol/L), a PKC activator. Pretreatment with N(G)-nitro-L-argingie methyl ester (L-NAME), a nitric oxide synthase (NOS) blocker, may inhibit significantly the role of L-Arg on Ang II - and PMA-activated PKC activity. The activity of PKC was also decreased by NO donor sodium nitroprusside (SNP) (10 micromol/L-1 mmol/L) in a dose-dependent manner in cultured neonatal rat cardiomyocytes. Pretreatment with SNP (10 micromol/L) decreased significantly Ang II - and PMA-activated PKC activity. These results indicate that PKC was controlled by both NO and Ang II. PKC may be a cross talk between Ang II and NO in cardiomyocytes. NO abolished the activity of PKC and impaired PKC downstream signaling transduction pathway cascades.
Fu
Shi-Gan
SG
Department of Physiology, Hainan Medical College, Haikou 571101. fushigan@yahoo.com.cn
Xie
Xie-Ju
XJ
Ji
Li-Min
LM
Liu
Pei-Qing
PQ
Pan
Jing-Yun
JY
Lu
Wei
W
D000804:Angiotensin II / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D005260:Female; D008297:Male; D032383:Myocytes, Cardiac / Q000166:cytology / Q000201:enzymology*; D009569:Nitric Oxide / Q000502:physiology*; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
D000804:Angiotensin II; D009569:Nitric Oxide; D011493:Protein Kinase C