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

This Article Full Text Full Text (PDF) All Versions of this Article: 293/4/H2262    most recent 01320.2006v1 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 Web of Science 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 Gutkowska, J. Articles by Jankowski, M. Search for Related Content PubMed PubMed Citation Articles by Gutkowska, J. Articles by Jankowski, M.

Functional arginine vasopressin system in early heart maturation

¹Centre de Recherche, Centre Hospitalier de l'Université de Montréal, Hôtel-Dieu, Montreal, Quebec, Canada; and ²Department of Internal Medicine III, University of Cologne, Cologne, Germany

Submitted 4 December 2006 ; accepted in final form 2 July 2007

Since the neurohypophyseal hormone 8-arginine vasopressin (AVP) is involved in cardiovascular tissue hypertrophy and myocyte differentiation, it is possible that local AVP plays a role in heart maturation. AVP-specific RIA, RT-PCR, and immunoblot measurement of AVP receptors (VR) were used to investigate heart tissues from newborn and adult rats. To test AVP's role in differentiation and specialization into ventricle-like cardiomyocytes, we studied GFP-P19Cl6 stem cells, which express green fluorescence protein (GFP) reporter under transcriptional control of the myosin light chain-2v promoter. VR₁ transcripts and proteins were higher in adult than in newborn rat hearts. In contrast, VR₂ increased from postnatal day 1 to 5 and was barely detected in the adult rat heart. In cardiomyocytes expressing troponin C, immunofluorescence revealed VR₂ and VR₁. Intracellular cAMP increased 6.5- and 8.9-fold in response to the selective VR₂ agonist 1-desamino-8-D-AVP (DDAVP) after 1 and 24 h, respectively. Cardiac AVP was high in 1- and 5-day-old (330 ± 26 and 276 ± 53 pg/mg protein, respectively) but low in 66-day-old (98 ± 15 pg/mg protein) rats. AVP immunostaining was detected in the tunica adventitia and endothelium of the coronary vessels. The possible role of AVP in cardiomyogenesis was indicated by DDAVP-AVP-dependent differentiation of GFP-P19Cl6 stem cells into contracting cells displaying GATA-4, a cardiac-specific marker, and ventricle-specific myosin light chain. Together, it is suggested that the AVP system is implicated in postnatal cardiac maturation.

vasopressin; heart maturation; vasopressin receptors; immunochemistry; cardiomyocyte differentiation