Nitric Oxide Does Not Downregulate Rho-Kinase (ROCK-2) Expression in Rat Coronary Endothelial Cells

• Published in: Journal of cardiovascular pharmacology Vol. 51; no. 2; pp. 140 - 147
• Main Authors: Tiftik, R Nalan, Erol, Ayşe, Çnar, Mehtap G, Kubat, Havva, Ark, Mustafa, Ülker, Sibel, Büyükafşar, Kansu
• Format: Journal Article
• Language: English
• Published: United States Lippincott Williams & Wilkins, Inc 01-02-2008
• Subjects: 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine - analogs & derivatives; 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine - pharmacology; Amides - pharmacology; Animals; Calcimycin - pharmacology; Cells, Cultured; Coronary Vessels - cytology; Coronary Vessels - enzymology; Down-Regulation; Endothelial Cells - enzymology; Gene Expression Regulation, Enzymologic; In Vitro Techniques; Male; Microcirculation - cytology; Microcirculation - enzymology; NG-Nitroarginine Methyl Ester - pharmacology; Nitric Oxide - physiology; Nitric Oxide Donors - pharmacology; Nitric Oxide Synthase - antagonists & inhibitors; Nitroglycerin - pharmacology; Nitroprusside - pharmacology; Pyridines - pharmacology; Rats; Rats, Wistar; rho-Associated Kinases - antagonists & inhibitors; rho-Associated Kinases - biosynthesis; Sodium Nitrite - pharmacology; Triazenes - pharmacology
• ISSN: 0160-2446; 1533-4023
• DOI: 10.1097/FJC.0b013e31815e4089

Rho kinase (ROCK) and nitric oxide (NO) are important targets in cardiovascular diseases. Therefore, we investigated the possible influence of NO on Rho kinase (ROCK-2 isoform) expressions in cultured rat coronary microvascular endothelial cells. The cells were isolated from Wistar rats on a Langendorff system, and were incubated overnight (~16 h) with an NO generator, A-23187 (10 to 10 M), NO donors, such as sodium nitroprusside (10 to 10 M), glyceryl trinitrate (10 to 10 M), 2,2′-(hydroxynitrosohydrazono)bis-ethanimine (10 to 10 M), and NaNO2 (10 to 10 M) or a nitric oxide synthase (NOS) inhibitor, N-nitro-L-arginine methylester (2×10 M), or two ROCK inhibitors, (+)-(R)-trans-4-(1-aminoethyl)- N-(4-pyridyl) cyclohexanecarboxamide dihydrochloride monohydrate (Y-27632, 10 M) and fasudil (10 M) in the absence or presence of thrombin (4 U/mL). ROCK-2 and endothelial NOS (eNOS) expressions were detected by Western blotting. Moreover, nitrite/nitrate levels were detected by Griess method in the presence of the ROCK inhibitors. The NO donors and the NO generator had no significant effects on ROCK-2 expression. Y-27632 and fasudil did not alter eNOS expression and NO production. Nitrite/nitrate levels were 4.4 ± 0.32 μM in control and 4.0 ± 0.93 μM and in Y-27632 group. These results demonstrate that prolong NO donation could not suppress the expression of ROCK-2 protein, and the ROCK inhibitor did not change e-NOS expression and NO production in the cultured rat coronary microvascular endothelial cells.