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This Article Full Text Full Text (PDF) All Versions of this Article: 296/1/L121    most recent 90318.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Perkins, W. J. Articles by Jones, K. A. Search for Related Content PubMed PubMed Citation Articles by Perkins, W. J. Articles by Jones, K. A.

Prolonged treatment of porcine pulmonary artery with nitric oxide decreases cGMP sensitivity and cGMP-dependent protein kinase specific activity

¹Departments of Anesthesiology and Physiology and Biophysics, Mayo Clinic College of Medicine, Rochester, Minnesota; and ²Department of Anesthesiology, University of Alabama, Birmingham, Alabama

Submitted 21 May 2008 ; accepted in final form 23 October 2008

A cultured porcine pulmonary artery (PA) model was used to examine the effects of prolonged nitric oxide (NO) treatment on the response to acutely applied NO, cGMP analog, or atrial natriuretic peptide (ANP). Twenty-four-hour treatment with the NO donor (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate (DETA-NO) resulted in >10-fold decrease in the response to acutely applied DETA-NO. In parallel with this, the relaxant response to acutely applied cGMP analog, β-phenyl-1,N²-etheno-8-bromoguanosine-3',5'-cyclic monophosphorothioate, Sp isomer (Sp-8-Br-PET-cGMPS), and ANP decreased. The reduction in ANP responsiveness in PA was not associated with a reduction in cGMP levels evoked by 10^–6 M ANP. Twenty-four hours in culture and treatment with DETA-NO decreased total cGMP-dependent protein kinase (cGKI) mRNA level compared with that in freshly prepared PA (1.05 ± 0.12, 0.42 ± 0.08, and 0.11 ± 0.01 amol/µg, respectively). Total cGKI protein levels were decreased to a lesser extent by 24 h in culture and further decreased by 24-h DETA-NO treatment compared with that in freshly prepared PA (361 ± 33, 272 ± 20, and 238 ± 25 ng/mg total protein, respectively). Maximal cGMP-stimulated phosphotransferase activity was reduced in 24-h cultured and DETA-NO-treated PA (986 ± 84, 815 ± 81, and 549 ± 78 pmol P_i·min^–1·mg soluble protein^–1), but the cGMP concentration resulting in 50% of maximal phosphotransferase activity was not. cGKI specific activity (maximal cGMP-activated phosphotransferase activity/ng cGKI) was significantly reduced in PA treated with DETA-NO for 24 h compared with freshly prepared and 24-h cultured PA (1.95 ± 0.22, 2.64 ± 0.25, and 2.85 ± 0.28 pmol P_i·min^–1·ng cGKI^–1, respectively). We conclude that prolonged NO treatment induces decreased acute NO responsiveness in PA in part by decreasing cGMP sensitivity. It does so by decreasing both cGKI expression and cGKI specific activity.

guanosine 3',5'-cyclic monophosphate; guanosine 3',5'-cyclic monophosphate-dependent protein kinase