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 Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Nakamura, H. Articles by Mizutani, S. Search for Related Content PubMed PubMed Citation Articles by Nakamura, H. Articles by Mizutani, S.

Oxytocin Stimulates the Translocation of Oxytocinase of Human Vascular Endothelial Cells Via Activation of Oxytocin Receptors¹

Maternity and Perinatal Care Center (H.N.) and Division of Pathology, Clinical Laboratory (T.N.), Nagoya University Hospital, Showa-ku, Nagoya 466-8550, Japan; and Department of Obstetrics and Gynecology, Nagoya University School of Medicine (A.I., M.O., M.I., A.I., M.O., S.M.), Showa-ku, Nagoya 466-8550, Japan

Address all correspondence and requests for reprints to: Atsuo Itakura M.D., Department of Obstetrics and Gynecology, Nagoya University School of Medicine, 65 Tsuruma-cho, Showa-ku, Nagoya 466-8550, Japan. E-mail: aita{at}med.nagoya-u.ac.jp

Oxytocinase (OTase) degrades several small peptides such as oxytocin (OT), and thus plays important roles in fetal development and maintenance of human homeostasis during pregnancy. The physiological effects of OT are mediated via its receptor (OTR). Although the interactions between OT and OTR have studied extensively, the relationship to OTase remains to be clarified. It is known that human umbilical vascular endothelial cells express OTR messenger RNA; therefore, they were selected for examination of this question in the present study.

RT-PCR experiments confirmed the existence of messenger RNA for OTase, and assessment of protein levels and activity clarified that OT increases the activity of OTase at the cell surface via binding to OTR. This stimulation appears to involve translocation of OTase from cytosolic to the cell surface in response to cellular signal transduction pathways linked to the OTR. Protein kinase C stimulation significantly increased the cell surface activity of OTase, whereas its inhibition resulted in reduction.

In summary, our findings provide clear evidence that OT triggers directly OTase translocation in human umbilical vascular endothelial cells via a protein kinase C-dependent pathway coupled to OTR.

This article has been cited by other articles:

				M. G. Wallis, M. F. Lankford, and S. R. Keller Vasopressin is a physiological substrate for the insulin-regulated aminopeptidase IRAP Am J Physiol Endocrinol Metab, October 1, 2007; 293(4): E1092 - E1102. [Abstract] [Full Text] [PDF]

				H. Kobayashi, S. Nomura, T. Mitsui, T. Ito, N. Kuno, Y. Ohno, K. Kadomatsu, T. Muramatsu, T. Nagasaka, and S. Mizutani Tissue Distribution of Placental Leucine Aminopeptidase/Oxytocinase During Mouse Pregnancy J. Histochem. Cytochem., January 1, 2004; 52(1): 113 - 122. [Abstract] [Full Text] [PDF]

				T. Tanioka, A. Hattori, S. Masuda, Y. Nomura, H. Nakayama, S. Mizutani, and M. Tsujimoto Human Leukocyte-derived Arginine Aminopeptidase: THE THIRD MEMBER OF THE OXYTOCINASE SUBFAMILY OF AMINOPEPTIDASES J. Biol. Chem., August 22, 2003; 278(34): 32275 - 32283. [Abstract] [Full Text] [PDF]

				G. Vauquelin, Y. Michotte, I. Smolders, S. Sarre, G. Ebinger, A. Dupont, and P. Vanderheyden Cellular targets for angiotensin II fragments: pharmacological and molecular evidence Journal of Renin-Angiotensin-Aldosterone System, December 1, 2002; 3(4): 195 - 204. [Abstract] [PDF]

				S. R. Keller, A. C. Davis, and K. B. Clairmont Mice Deficient in the Insulin-regulated Membrane Aminopeptidase Show Substantial Decreases in Glucose Transporter GLUT4 Levels but Maintain Normal Glucose Homeostasis J. Biol. Chem., May 10, 2002; 277(20): 17677 - 17686. [Abstract] [Full Text] [PDF]

				S. Toda, H. Ando, T. Nagasaka, S.-I. Tsukahara, M. Nomura, Y. Kotani, S. Nomura, F. Kikkawa, M. Tsujimoto, and S. Mizutani Existence of Placental Leucine Aminopeptidase/Oxytocinase/Insulin-Regulated Membrane Aminopeptidase in Human Endometrial Epithelial Cells J. Clin. Endocrinol. Metab., March 1, 2002; 87(3): 1384 - 1389. [Abstract] [Full Text] [PDF]