Expression of protein-gene peptide (PGP) 9.5 in myocardial sleeves around the pulmonary artery and aorta in pigs

Abstract

A subgroup of outflow tract (OT) ventricular tachycardias (VT) originates from the aortic sinuses or the main
stem of the pulmonary artery. Myocardial sleeves onto the pulmonary artery (PA) and aorta (Ao) have been
recognized as a frequent site for the origin of arrhythmia. The aim of this study was to analyze PGP9.5
expression in pulmonary artery and aorta from 100 pigs hearts and relate it to the mechanism of arrhythmia.
The pulmonary artery and aorta were obtained from 100 healthy pigs; longitudinal strips of tissue containing
each cusp, aortic, pulmonary artery walls, left and right ventricular outflow tracts were excised and
histologically analyzed. PGP9.5 was studied immunohistochemically in myocardial sleeves. Myocardial
sleeves were found in 88 of 100 Aos (88%) and 20 of 100 PAs (20%). PGP9.5 positivity was observed in 89 of 90
(99%) pigs, which had myocardial sleeves. PGP9.5 immunopositivity can be detected in most pig myocardial
sleeves around the PAs and Aos; this finding may contribute to the substrate for OT VTs.