The ability of phosphodiesterase-5 inhibitors sildenafil and ordonafil to reverse L-NAME induced cardiac hypertrophy in the rabbit: possible role of calcineurin and p38.
Phosphodiesterase 5 inhibitors (PDE-5Is) can suppress and (or) reverse pressure overload induced myocardial hypertrophy. This study investigated the suppressive effect of 2 PDE-5Is (sildenafil and ordonafil) on N-nitro-l-arginine methyl ester (L-NAME)-induced cardiac hypertrophy in rabbit heart, and examined their possible mechanism of action. L-NAME increased left ventricular thickness to 6.1± 0.18 mm from 4.6 ± 0.13 mm (p < 0.05), which regressed after treatment with either sildenafil or ordonafil to 5.1 ± 0.1 mm and 4.8 ± 0.2 mm, respectively (p < 0.05). Phenylephrine increased neonatal rat ventricular myocyte cell surface area to 131% ± 3% of the control value, which was associated with significant increment in ERK1/2 to 143% ± 5% of the control value (p < 0.05). Ordonafil and sildenafil decreased cell surface area to 95% ± 3% and 90% ± 1% of the control value, respectively. Both drugs decreased ERK1/2 to 88% ± 4% of the control value. Calcineurin activity was significantly decreased after 1 h of treatment with 0.1 mg·L(-1) ordonafil (1.15 ± 0.05, p < 0.05). For sildenafil (0.1 mg·L(-1)), calcineurin activity significantly decreased only after 24 h of incubation (22%). Also p38 activation was attenuated by ordonafil and sildenafil (0.1 mg·L(-1)). It is suggested that both drugs have the ability to reverse L-NAME-induced cardiac hypertrophy and suppress phenylphrine-induced myocyte hypertrophy, and that these effects may be mediated through the attenuation of calcineurin and its downstream signaling pathways (p38) in neonatal rat ventricular myocytes.
Department of Anatomy, Cell Biology, and Physiological Sciences, American University of Beirut, Lebanon.
Asad
A
Zeidan
Aiad
A
Siam
Abdulaziz
A
Al Kaabba
Mukhallad
M
Mohammad
Said
S
Khatib
D000818:Animals; D019703:Calcineurin / Q000378:metabolism*; D006332:Cardiomegaly / Q000139:chemically induced / Q000201:enzymology / Q000473:pathology / Q000517:prevention & control*; D048429:Cell Size / Q000187:drug effects; D005260:Female; D008297:Male; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*; D058986:Phosphodiesterase 5 Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D010879:Piperazines / Q000494:pharmacology* / Q000627:therapeutic use; D011687:Purines / Q000494:pharmacology / Q000627:therapeutic use; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000494:pharmacology* / Q000627:therapeutic use; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
C475878:JPM8 compound; D058986:Phosphodiesterase 5 Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate; D048051:p38 Mitogen-Activated Protein Kinases; D019703:Calcineurin; D019331:NG-Nitroarginine Methyl Ester