Identification and Expression of Cardiac Contractry Protein Troponin T by Antenatal Glucocorticoid Therapy in Fetal and Infant Rats

Pediatric Cardiology and Cardiac Surgery
Vol.24 No.1 2008 (35-43)

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Yoshimitsu Tsuzuki,¹⁾ Yuko Takeba,1), Toshio Kumai,¹⁾,Naoki Matsumoto,¹⁾ Kentaro Asoh,²⁾ Kohtaro Murano,²⁾,Masanori Mizuno,²⁾ and Shinichi Kobayashi¹⁾

Departments of ¹⁾Pharmacology and ²⁾Pediatrics, St. Marianna University School of Medicine, Kanagawa, Japan

Abstract

Background: We investigate the effects of antenatal glucocorticoid (GC) on the fetal and neonatal expression of a variety of proteins related to cardiac function.
Methods: Dexamethasone (DEX) was administered to pregnant Wistar rats and fetuses of 19 and 21 days gestation, and 1-3- and 5-day-old neonatal rats were sacrificed. We identified the differentiated proteins from the fetal and neonatal hearts using a liquid chromatography mass spectrometry/mass spectrometry (LC/MS/MS) technique.
Results: In vehicle control groups, troponin T expression decreased as the maturational age of the fetuses and neonates increased. Tropinin T expression was increased significantly in the DEX group compared to vehicle controls in the 19- and 21-day fetuses. Furthermore, accompanying the increased troponin T expression, DEX increased the expression of cardiac-specific transcription factor GATA-4 in fetuses.
Conclusions: These results suggest that antenatal GC therapy increases expression of troponin T and may contribute to development on immature fetal myocardium.