Differential localization of atrial natriuretic peptide and skeletal alpha-actin messenger RNAs in left ventricular myocytes of patients with dilated cardiomyopathy.
OBJECTIVE
This study was designed to determine whether atrial natriuretic peptide and skeletal alpha-actin messenger RNAs (mRNAs) are co-localized in ventricular myocytes of patients with dilated cardiomyopathy.


BACKGROUND
Atrial natriuretic peptide and skeletal alpha-actin are known as augmented genes with cardiac hypertrophy. However, the expression and localization of both genes in chronic failing heart remain unclear.


METHODS
Left ventricular biopsy specimens were obtained from 14 patients with dilated cardiomyopathy. Atrial natriuretic peptide and skeletal alpha-actin mRNAs were detected by in situ hybridization with specific sulfur-35 uridine triphosphate-labeled RNA probes in the serial sections.


RESULTS
Atrial natriuretic peptide mRNA was detected in 10 patients, and intense signals were localized in the myocytes located in the subendocardium and around the interstitial fibrous area. By contrast, skeletal alpha-actin mRNA was homogeneously detected in all myocytes in seven patients. By left ventriculography, patients with skeletal alpha-actin-positive findings had a lower ejection fraction (37.1 +/- 6.0%) than those with negative findings (46.3 +/- 5.8%, p < 0.05), but atrial natriuretic peptide mRNA expression was not related to left ventricular function.


CONCLUSIONS
These results indicate that the expression of atrial natriuretic peptide and skeletal alpha-actin mRNAs are not always co-localized in the left ventricle of patients with dilated cardiomyopathy and suggest that the mechanisms of the regulation of these two genes in the chronic failing heart are different.
Tanaka
M
M
Second Department of Internal Medicine, Tokyo Medical and Dental University, Tokyo Women's Medical College, Japan.
Hiroe
M
M
Ito
H
H
Nishikawa
T
T
Adachi
S
S
Aonuma
K
K
Marumo
F
F
D000199:Actins / Q000032:analysis / Q000235:genetics*; D000328:Adult; D000368:Aged; D009320:Atrial Natriuretic Factor / Q000032:analysis / Q000235:genetics*; D001706:Biopsy; D002311:Cardiomyopathy, Dilated / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology; D005260:Female; D015870:Gene Expression; D006352:Heart Ventricles / Q000737:chemistry; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000737:chemistry*; D012333:RNA, Messenger / Q000032:analysis*; D013318:Stroke Volume; D016277:Ventricular Function, Left
D000199:Actins; D012333:RNA, Messenger; D009320:Atrial Natriuretic Factor