Cardiocyte nuclear chromatin density correlates with transplanted heart left ventricular mass.
BACKGROUND
Cardiocyte hypertrophy is accompanied by polyploidy, seen as a decrease in chromatin density in the enlarged nucleus. Repeated biopsies of a transplanted heart offer the possibility of a dynamic evaluation of these phenomena. The aim of this work was an evaluation of cardiocyte nuclear chromatin density in transplanted hearts during long-term follow-up.


METHODS
The material encompassed myocardial biopsy specimens taken during the first week, first month, and then on an annual basis up to 10 years after surgery. Only biopsy specimens with no rejection were considered (grade "0" International Society for Heart and Lung Transplantation [ISHLT] 122 biopsy specimens). The control group consisted of 7 donor heart specimens. We evaluated the optical density-mean gray level-of cardiomyocyte nuclear chromatin. We determined correlations of this index with the nuclear area, and with left ventricle ultrasound measurements, using correlation analysis.


RESULTS
The chromatin mean gray level decreased with time, correlating positively with interventricular septum thickness, left ventricle posterior wall diameter, and left ventricular mass. Analysis of individual periods showed a significant positive correlation of the mean grey level with the cardiocyte nuclear surface in year 3, 4, and 9 after transplantation, thereby suggesting the occurrence of polyploidy at those times. The significant negative correlation of these values (1 week and 1 year) indicated normalization of early cardiocyte hypertrophy.


CONCLUSIONS
With the passage of time chromatin condenses, leading to pyknosis. The activity of cardiocyte chromatin correlated with left ventricular hypertrophy. Compensatory cardiomyocyte polyploidy is a periodical phenomenon.
Nozyński
J
J
Department of Cardiac Surgery & Transplantation, Silesian Center for Heart Disease, Zabrze, Poland.
Zakliczyński
M
M
Zembala-Nozyńska
E
E
Konecka-Mrówká
D
D
Przybylski
R
R
Nikiel
B
B
Mlynarczyk-Liszka
Joanna
J
Lange
D
D
Mrówka
A
A
Przybylski
J
J
Maruszewski
M
M
Zembala
M
M
D002467:Cell Nucleus / Q000473:pathology; D002843:Chromatin / Q000648:ultrastructure*; D004452:Echocardiography; D005500:Follow-Up Studies; D016678:Genome; D006346:Heart Septum / Q000473:pathology; D016027:Heart Transplantation / Q000473:pathology / Q000502:physiology*; D006352:Heart Ventricles / Q000033:anatomy & histology* / Q000473:pathology; D006801:Humans; D032383:Myocytes, Cardiac / Q000166:cytology*; D011123:Polyploidy; D011183:Postoperative Complications / Q000473:pathology; D012189:Retrospective Studies; D013997:Time Factors
D002843:Chromatin