This Article Full Text Full Text (PDF) 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 Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Veltkamp, R. Articles by Busija, D. Search for Related Content PubMed PubMed Citation Articles by Veltkamp, R. Articles by Busija, D. Pubmed/NCBI databases Substance via MeSH Medline Plus Health Information Transient Ischemic Attack Related Collections Animal models of human disease Gene expression Endothelium/vascular type/nitric oxide

(Stroke. 2002;33:2704.)
© 2002 American Heart Association, Inc.

Original Contributions

Transient Focal Ischemia Increases Endothelial Nitric Oxide Synthase in Cerebral Blood Vessels

Roland Veltkamp, MD; Nishadi Rajapakse, MS; Greg Robins, MS; Michelle Puskar, MS; Katsuyoshi Shimizu, MD David Busija, PhD

From the Department of Physiology and Pharmacology and Center for Investigative Neuroscience (R.V., M.R., G.R., M.P., K.S., D.B.), Wake Forest University School of Medicine, Winston-Salem, NC, and Department of Neurology (R.V.), Ruprecht-Karls-University, Heidelberg, Germany.

Correspondence to Roland Veltkamp, MD, Department of Neurology, Ruprecht-Karls-University Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany. E-mail roland_veltkamp{at}med.uni-heidelberg.de

Background and Purpose— Production of NO by endothelial NO synthase (eNOS) plays a protective role in cerebral ischemia. We studied the effects of transient focal ischemia on eNOS expression.

Methods— Wistar rats (n=72) underwent reversible filament occlusion of the right middle cerebral artery for 75 minutes. After 6, 24, 72, or 168 hours of reperfusion, brains were removed and coronal sections cut for eNOS immunohistochemistry, eNOS–alkaline phosphatase costaining, and hematoxylin-eosin staining. Samples for eNOS immunoblots were taken from corresponding striatum and overlying parietal cortex bilaterally.

Results— eNOS protein occurred in virtually all blood vessels and was consistently increased in microvessels in the ischemic striatum after 24 to 168 hours of reperfusion but not at 6 hours. eNOS upregulation in the parietal cortex was only present in animals with evidence of cortical infarcts documented on adjacent HE-stained sections. Costaining of endogenous alkaline phosphatase and eNOS demonstrated eNOS expression in all segments of cerebral microvessels. Quantitative analysis of eNOS immunostaining and immunoblots showed no attenuated increase in animals that were treated with indomethacin (5 mg/kg IP), NS398 (20 mg/kg IP), or L-arginine-methyl ester (10 mg/kg IP). In contrast to eNOS, levels of brain NOS did not increase after ischemia.

Conclusion— eNOS protein is upregulated in pre- and postcapillary microvessels and upregulation appears slower after transient compared with permanent ischemia. Cyclooxygenase and NOS products do not play a major role in postischemic eNOS induction.

Key Words: cerebral ischemia • gene expression • nitric oxide • reperfusion • rats

This article has been cited by other articles:

				S. Gao, C.-L. Long, R.-H. Wang, and H. Wang KATP activation prevents progression of cardiac hypertrophy to failure induced by pressure overload via protecting endothelial function Cardiovasc Res, August 1, 2009; 83(3): 444 - 456. [Abstract] [Full Text] [PDF]

				N. Toda, K. Ayajiki, and T. Okamura Cerebral Blood Flow Regulation by Nitric Oxide: Recent Advances Pharmacol. Rev., March 1, 2009; 61(1): 62 - 97. [Abstract] [Full Text] [PDF]

				R. H. Fabian, J. R. Perez-Polo, and T. A. Kent Perivascular nitric oxide and superoxide in neonatal cerebral hypoxia-ischemia Am J Physiol Heart Circ Physiol, October 1, 2008; 295(4): H1809 - H1814. [Abstract] [Full Text] [PDF]

				J. Pretnar-Oblak, M. Sabovic, M. Sebestjen, T. Pogacnik, and M. Zaletel Influence of Atorvastatin Treatment on L-Arginine Cerebrovascular Reactivity and Flow-Mediated Dilatation in Patients With Lacunar Infarctions Stroke, October 1, 2006; 37(10): 2540 - 2545. [Abstract] [Full Text] [PDF]

				S. Gingerich and T. L. Krukoff Estrogen Modulates Endothelial and Neuronal Nitric Oxide Synthase Expression via an Estrogen Receptor {beta}-Dependent Mechanism in Hypothalamic Slice Cultures Endocrinology, July 1, 2005; 146(7): 2933 - 2941. [Abstract] [Full Text] [PDF]

				J. C. Drummond, L. D. McKay, D. J. Cole, and P. M. Patel The Role of Nitric Oxide Synthase Inhibition in the Adverse Effects of Etomidate in the Setting of Focal Cerebral Ischemia in Rats Anesth. Analg., March 1, 2005; 100(3): 841 - 846. [Abstract] [Full Text] [PDF]

				K. Osuka, Y. Watanabe, N. Usuda, A. Nakazawa, M. Tokuda, and J. Yoshida Modification of Endothelial NO Synthase Through Protein Phosphorylation After Forebrain Cerebral Ischemia/Reperfusion Stroke, November 1, 2004; 35(11): 2582 - 2586. [Abstract] [Full Text] [PDF]

				T. Altay, E. R. Gonzales, T. S. Park, and J. M. Gidday Cerebrovascular inflammation after brief episodic hypoxia: modulation by neuronal and endothelial nitric oxide synthase J Appl Physiol, March 1, 2004; 96(3): 1223 - 1230. [Abstract] [Full Text] [PDF]