AgNORs in the myocardium in ischaemic heart disease complicated by heart failure: a postmortem study

To evaluate the interphase ribosomal RNA cistron activity of cardiomyocytes in case with ischaemic heart disease complicated by heart failure.

Nucleoli were investigated in postmortem myocardium samples from 31 cases with ischaemic heart disease (mean (SEM), 57.4 (6.5) years) with or without severe heart failure (18 and 13, respectively) and from eight healthy people who died in accidents (mean (SEM) 25.3 (4.0) years). Myocardium obtained within one hour after death was frozen in liquid nitrogen. Silver staining for nucleolar organiser regions (AgNOR) was performed with a standard procedure and the mean score obtained. On the basis of these data, the average number of AgNORs per nucleus was determined. The Student's t test was used to compare groups.

Compared with controls, the mean numbers of AgNORs per nucleus in cardiomyocytes from ischaemic heart disease patients not complicated with severe heart failure were higher (8.0 v 9.9; p < 0.05), but cases with severe heart failure had a progressive decrease in cardiomyocyte AgNORs. A difference in AgNOR numbers between cases with different ischaemic heart disease courses was found when cases with the same New York Heart Association (NYHA) functional stage III of heart failure were studied.

The significant decrease of AgNORs in cardiomyocytes from cases with severe ischaemic heart disease complicated by heart failure seems to be connected with cardiomyocyte adaptation (a variant of hibernation) to a diminished circulation that, hypothetically, may affect the level of ribosomal RNA synthesis.