Leaf senescence is a highly regulated process, in which events occur in an ordered manner

e this respect, a good biomarker also correlates with the clinical improvement of the disease. Correlation of sACE2 was therefore also investigated upon the clinical improvement after biventricular pacemaker implantation. A robust reduction in serum ACE2 activity was found in parallel to the improving cardiac performance and function called reverse remodeling. Regression analyses of serum ACE2 as a function of EF after CRT revealed that the correlation remained negative, and positive correlation of sACE2 activity to ESD and EDD was also preserved. 5 Circulating ACE2 in Human Heart Failure 6 Circulating ACE2 in Human Heart Failure also determined with respect of the New York Heart Association functional class of the patients before and after CRT. Statistical analyses of healthy people, hypertensive, HF – CRT before and HF CRT after groups were performed by oneway analysis of variance followed by Newman-Keuls test for multiple comparisons between groups. Bars are mean 6 S.E.M. Significant differences are labeled by asterisks. doi:10.1371/journal.pone.0087845.g002 Correlation of sACE2 activity with NT-proBNP There was no correlation between sACE2 activity and NTproBNP in individuals with normal left ventricular systolic function. Serum ACE2 activities positively correlated to NT-proBNP levels in HF patients before CRT. This positive correlation of sACE2 activity and NTproBNP was maintained after CRT. . Moreover, serum ACE concentration increased after pacemaker implantation. Nevertheless, regression analyses of ACE concentration as a function of EF before CRT or after CRT did not PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19643932 show any significant correlations. Discussion Correlation of serum ACE activity and concentration to left ventricular systolic function ACE activity of the cardiovascular patients were significantly lower than that in healthy individuals, most probably representing successful ACE inhibitory therapy. Patients with severe systolic heart failure had significantly lower enzyme concentration than patients with preserved EF One of the most frequent cardiovascular diseases is hypertension. It leads to secondary cardiomyopathy, coronary artery disease, stroke, peripheral artery disease, chronic nephropathy, neuropathy and many other severe pathologies and ultimately increases mortality. Interestingly, most of the cases do not have identifiable cause. It is important to note, that there are effective treatments for hypertension, making it a relatively easily manageable disease, but there is no cure for it, which is probably related to the issue, that the very 7 Circulating ACE2 in Human Heart Failure cause of the MedChemExpress SKI II disease is not known. As a result, patients are treated and their blood pressure is kept at an acceptable level, but their background pathology causing the hypertension may be unaffected. Here we found for the first time that serum ACE2 activities are increased in hypertensive patients compared to healthy individuals. Nonetheless, these hypertensive patients already had a barely decreased ejection fraction compared to the healthy population and also featured slightly elevated NT-proBNP levels, suggesting that this population is at imminent heart failure. At this stage of the disease serum ACE2 activity was already elevated although it did not correlate with NT-proBNP levels. It appears therefore, that serum ACE2 activity is another biomarker of imminent heart failure in hypertension. Importantly, sACE2 may also be related to the cause of the disease. It can regula