TRANSLATIONAL NEUROSCIENCES - SHORT COMMUNICATION A comparison between radiometric and fluorimetric methods for measuring SSAO activity Alejandro Gella • Montse Sole ´ • Irene Bolea • Mariacarla Ventriglia • Mariacristina Siotto • Nuria Durany • Rosanna Squitti • Mercedes Unzeta Received: 14 October 2012 / Accepted: 28 January 2013 / Published online: 12 February 2013 Ó Springer-Verlag Wien 2013 Abstract Semicarbazide-sensitive amine oxidase (SSAO) metabolizes the oxidative deamination of primary aromatic and aliphatic amines. The final cytotoxic products of its catalysis contribute to diseases involving vascular degen- eration. The increasing interest in measuring SSAO activity has led to the development of several different methods. Herein, we compare SSAO activity results obtained with radiometric and fluorimetric methods in 49 plasma samples. Although not interchangeable, a significant correlation was obtained between methods. Considering these limitations, the fluorimetric method might replace the radioisotopic one. Keywords Biomarkers Á Fluorimetric Á Method comparison Á Radiometric Á Semicarbazide-sensitive amine oxidase Abbreviations SSAO Semicarbazide sensitive amine oxidase AD Alzheimers’s disease CAA Cerebral amyoid angiopathy VAP-1 Vascular adhesion protein-1 MMSE Mini-mental state examination CI Confidence intervals Introduction Semicarbazide-sensitive amine oxidase [E.C.1.4.3.21, amine:oxygen oxidoreductase (deaminating) (copper-con- taining), SSAO], also known as vascular adhesion protein-1 (VAP-1), is associated with cell membranes and it is also shedded to plasma as soluble form (Abella et al. 2004). Found in almost all mammalian tissues, the membrane- bound form shows high activity in endothelial and smooth muscle cells of blood vessels (Lewinsohn 1984; Castillo et al. 1998). SSAO metabolizes the oxidative deamination of primary aromatic and aliphatic amines and generates ammonia, hydrogen peroxide and the corresponding alde- hyde. Besides its catalytic activity, SSAO has been descri- bed as a multifunctional enzyme whose function varies depending on the tissue where it is expressed (O’Sullivan et al. 2004). SSAO has been extensively investigated with respect to its role in various pathophysiological conditions. It has been reported that soluble SSAO activity is altered in patients suffering from diabetes type I and II (Boomsma et al. 1995), atherosclerosis (Kara ´di et al. 2002), congestive To our deep regret Professor Nu ´ria Durany passed away on August 27th 2010 after an intense but short fighting an illness. We shall continue to cherish her passion for science. A. Gella Á N. Durany Department of Basic Sciences, Facultat de Medicina, Universitat Internacional de Catalunya, Sant Cugat del Valle `s, Spain M. Sole ´ Á I. Bolea Á M. Unzeta (&) Departament de Bioquı ´mica i Biologia Molecular, Facultat de Medicina, Institut de Neurocie `ncies, Universitat Auto `noma de Barcelona, Bellaterra, 08193 Barcelona, Spain e-mail: Mercedes.unzeta@uab.cat; Mercedes.Unzeta@uab.es M. Ventriglia Á R. Squitti Department of Neurology, ‘‘Campus Biomedico’’ University, Rome, Italy M. Ventriglia Á R. Squitti Department of Neuroscience, AFaR, Fatebenefratelli Hospital, Isola Tiberina, Rome, Italy M. Siotto Don Carlo Gnocchi Foundation ONLUS, Milan, Italy 123 J Neural Transm (2013) 120:1015–1018 DOI 10.1007/s00702-013-0987-z