Microscopy and Microanalysis


Epicardial Development in the Rat: A New Perspective

Tresa  Nesbitt  a1 , Aubrey  Lemley  a1 , Jeff  Davis  a1 , Michael J.  Yost  a1 , Richard L.  Goodwin  a1 and Jay D.  Potts  a1 c1
a1 Department of Cell & Developmental Biology and Anatomy, University of South Carolina, School of Medicine, Columbia, SC 29209, USA

Article author query
nesbitt t   [PubMed][Google Scholar] 
lemley a   [PubMed][Google Scholar] 
davis j   [PubMed][Google Scholar] 
yost mj   [PubMed][Google Scholar] 
goodwin rl   [PubMed][Google Scholar] 
potts jd   [PubMed][Google Scholar] 


Development of the epicardium is critical to proper heart formation. It provides all of the precursor cells that form the coronary system and supplies signals that stimulate cardiac myocyte proliferation. The epicardium forms from mesothelial cells associated with the septum transversum and is referred to as the proepicardium (PE). Two different methods by which these PE cells colonize the developing heart have been described. In avians, PE cells form a bridge to the heart over which PE cells migrate onto the heart. In fish and mammals, PE cells form vesicles of cells that detach from the mesothelium, float through the pericardial cavity, and attach to the heart. A previous study of rat PE development investigated this process at the histological level. Protein markers have been developed since this study. Thus, we investigated this important developmental process coupled with these new markers using other visualization techniques such as scanning electron microscopy (SEM) and confocal microscopy. Finally, a novel, three-dimensional (3-D) culture system was used to confirm the identity of the PE cells. In this study, we found convincing evidence that the rat PE cells directly attach to the heart in a manner similar to that observed in avians.

(Received March 3 2006)
(Accepted June 2 2006)

Key Words: proepicardium; epicardium; heart development; coronary vasculogenesis.

c1 Corresponding author. E-mail: jpotts@med.sc.edu