HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted 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 HighWire Citing Articles via Google Scholar Google Scholar Articles by Shouda, S. Articles by Wakabayashi, Y. Search for Related Content PubMed PubMed Citation Articles by Shouda, S. Articles by Wakabayashi, Y.

Effects of Extrinsically Elevated Plasma Norepinephrine Concentration on Myocardial ¹²³I-MIBG Kinetics in Rats

Department of Medicine III, Hamamatsu University School of Medicine, Hamamatsu, Japan

Correspondence: For correspondence or reprints contact: Sakae Shouda, MD, Department of Medicine III, Hamamatsu University School of Medicine, 3600 Handa-cho, Hamamatsu 431-3192, Japan.

ABSTRACT

Rapid ¹²³I-metaiodobenzylguanidine (MIBG) washout and high plasma norepinephrine (NE) levels are frequently observed in patients with congestive heart failure, and high plasma NE levels are not necessarily induced by increased cardiac NE spillover. The purpose of this study was to assess the effect of extrinsically elevated plasma NE levels on myocardial MIBG kinetics. Methods: MIBG was injected into the femoral vein in 47 adult male Wister rats. In the first study, normal saline solution or NE (0.3, 1.0 and 3.0 µg/kg/min) was administered to each group of 6 or 7 rats continuously from 30 min before to 30 min after MIBG injection. In the second study, NE was administered at 3.0 µg/kg/min to each group of 7 rats continuously from 30 min before to 2 h after or from 30 to 60 min after MIBG injection, and NE was not administered to a control group of 7 rats. For 2 or 4 h after MIBG injection, scintigrams were acquired using a gamma camera with a pinhole collimator, after which myocardial MIBG uptake (percentage injected dose normalized for the difference in rat weight per tissue weight) was determined in isolated heart with a gamma counter. Results: In the first study, the MIBG washout rate from the heart was significantly increased during high-dose NE infusion (1.0 and 3.0 µg/kg/min) compared with that during saline infusion, whereas the washout rate was not increased during low-dose NE infusion. In the second study, the MIBG washout rate from the heart during NE infusion was significantly increased compared with that of the control but was not increased during discontinuation of NE infusion. Conclusion: Extrinsically induced high levels of plasma NE may accelerate MIBG washout from the heart.

Key Words: metaiodobenzylguanidine • rat • norepinephrine • myocardium

This article has been cited by other articles:

				C. Kurata, A. Uehara, and A. Ishikawa Improvement of Cardiac Sympathetic Innervation by Renal Transplantation J. Nucl. Med., July 1, 2004; 45(7): 1114 - 1120. [Abstract] [Full Text] [PDF]

				B. A. Eldadah, K. Pacak, G. Eisenhofer, C. Holmes, I. J. Kopin, and D. S. Goldstein Cardiac Uptake-1 Inhibition by High Circulating Norepinephrine Levels in Patients with Pheochromocytoma Hypertension, June 1, 2004; 43(6): 1227 - 1232. [Abstract] [Full Text] [PDF]

				A. Altmann, M. Kissel, S. Zitzmann, W. Kubler, M. Mahmut, P. Peschke, and U. Haberkorn Increased MIBG Uptake After Transfer of the Human Norepinephrine Transporter Gene in Rat Hepatoma J. Nucl. Med., June 1, 2003; 44(6): 973 - 980. [Abstract] [Full Text] [PDF]