Behavior of Atrial Natriuretic Factor in an Experimental Model of Trypanosoma cruzi Infection in Rats

Abstract

Enhanced atrial natriuretic factor (ANF) production by the heart is related to hemodynamic overload, cardiac growth, and hypertrophy. The heart is one of the most affected organs during Trypanosoma cruzi infection. We tested the hypothesis that myocarditis produced by parasite infection alters the natriuretic peptide system by investigating the behavior of plasma ANF during the acute and chronic stages of T. cruzi infection in rats. Sprague-Dawley rats were infected with T. cruzi clone Sylvio-X10/7. Cardiac morphology showed damage to myocardial cells and lymphocyte infiltration in the acute phase; and fibrosis and cell atrophy in the chronic period. Plasma ANF levels (radioimmunoassay) were significantly higher in acute (348 +/- 40 vs. 195 +/- 36 pg/ml, P < 0.05, n = 17) and chronic T. cruzi myocarditis (545 +/- 81 vs. 229 +/- 38 pg/ml, P < 0.001, n = 11) than in their respective controls (n = 10 and 14). Rats in the chronic phase also showed higher levels than rats in the acute phase (P < 0.01). The damage of myocardial cells produced by the parasite and the subsequent inflammatory response could be responsible for the elevation of plasma ANF during the acute period of T. cruzi infection. The highest plasma ANF levels found in chronically infected rats could be derived from the progressive failure of cardiac function.

Chagas Cardiomiopathy: The Potential of Diastolic Dysfunction and Brain Natriuretic Peptide in the Early Identification of Cardiac Damage

“…Natriuretic peptides have been shown to be involved in the pathogenesis of Chagas disease in animal experiments [23], [24] and some clinical studies have reported that BNP levels are increased in Chagas cardiomyopathy [25], [26], [27] and correlates with prognosis [28]. Ribeiro et al demonstrated a high specificity with moderate sensitivity for BNP to detect LVEF≤40% in infected patients with an abnormal ECG or chest X-ray [25].…”

State-of-the-art in host-derived biomarkers of Chagas disease prognosis and early evaluation of anti-Trypanosoma cruzi treatment response

“…Natriuretic peptides (brain and atrial) were among the first markers of cardiac disease progression ever considered. These are released under conditions of myocardial stress and have been shown to be increased in T. cruzi experimentally infected animals (21), and in Chagas disease patients with cardiomyopathy (22). Furthermore, levels of natriuretic peptides correlated to clinical prognosis (23).…”