Monoamine oxidase A inhibition protects the myocardium after experimental acute volume overload

The molecular pathway leading to myocardial cellular destruction after acute volume overload (AVO) may include monoamine oxidases. The aim of the present study was to investigate whether moclobemide (Mo), a monoamine oxidase inhibitor, protects the myocardium after AVO.

Sixty syngeneic Fischer rats underwent surgical abdominal aortocaval fistula to induce AVO. Eighteen rats were treated with Mo 10 mg/kg/day and were compared with 42 untreated rats with AVO without treatment. Myocardial recovery was analyzed using quantitative reverse transcription polymerase chain reaction for hypoxia-inducible factor 1-alpha, inducible nitric oxide synthase, interleukin 6, E-selectin, atrial natriuretic peptide (ANP), brain natriuretic peptide, vascular endothelial growth factor-alpha, matrix metalloproteinase 9, chitinase 3-like protein (YKL-40), and transforming growth factor-beta.

After 3 days, the relative number of ischemic intramyocardial arteries in the left ventricle was lower in AVO treated with Mo than in without [0.04 (0.02-0.07) vs. 0.09 (0.07-0.14), point score unit]. After 1 day, ANP was lower in AVO treated with Mo than in without [0.95 (0.37-1.84) vs. 2.40 (1.33-3.09), fold changes from the baseline (FC), p=0.044], whereas after 1 and 3 days, YKL-40 was higher in AVO treated with Mo than in without [22.66 (14.05-28.83) vs. 10.06 (6.23-15.02), FC, p=0.006 and 6.03 (4.72-7.18) vs. 3.70 (2.62-5.35), FC, p=0.025].

Mo decreases intramyocardial arterial ischemia of the left ventricle after AVO while increases YKL-40, reflecting cellular protection during early cardiac remodeling. In the future, adding Mo may be a simple means for myocardial protection after AVO.