Changes in circulating atrial natriuretic peptide in relation to the cardiac status of Rhesus monkeys after total-body irradiation.
OBJECTIVE
In order to determine the presence of cardiac damage associated with total-body irradiation (TBI), both echocardiographic parameters and circulating levels of atrial natriuretic peptide (ANP) were measured in three different age-cohorts of Rhesus monkeys (Macaca mulatta) previously treated with TBI without additional chemotherapy, at post irradiation intervals up to 30 years, at the former TNO/Radiobiological Institute at Rijswijk.


METHODS
Standard echocardiographic techniques were used to measure cardiac dimensions and left ventricular function in situ. Plasma-ANP concentration was measured by radioimmunoassay (RIA). After necropsy, tissue samples from the heart were taken for histological analysis.


RESULTS
Plasma-ANP levels of animals which received TBI were significantly (P = 0.0005) elevated when compared to age-matched controls (66.4 +/- 8.4 vs. 33.1 +/- 5.7 ng/l). Moreover, a positive correlation (P = 0.032) between plasma-ANP values and time post treatment was found in the TBI group. TBI affected cardiac dimensions; however, no significant differences in cardiac functional parameters were observed between the different treatment groups. Necropsy reports demonstrated slight but consistent cardiovascular damage in several animals treated with TBI, in terms of increased incidence of mild epicardial and coronary arterial wall fibrosis, compared to age-matched controls.


CONCLUSIONS
The concentration of plasma-ANP proved to be an important parameter for subclinical cardiac damage. In humans, serial determinations of plasma ANP in individual patients might provide relevant information about the cardiac status after TBI.
Wondergem
J
J
Department of Clinical Oncology, KI-P. Leiden University Medical Center, The Netherlands.
Persons
K
K
Zurcher
C
C
Frölich
M
M
Leer
J W
JW
Broerse
J
J
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000097:blood*; D004452:Echocardiography; D006321:Heart / Q000528:radiation effects*; D008253:Macaca mulatta; D009206:Myocardium / Q000473:pathology; D011863:Radioimmunoassay; D016277:Ventricular Function, Left; D014916:Whole-Body Irradiation
D009320:Atrial Natriuretic Factor