TABAQUISM AND CARDIOMYOPHATIES. EFFECTS OF TOBACCO CONSUMPTION ON CARDIAC CALCIUM HANDLING IN Drosophila melanogaster

PARONZINI HERNANDEZ NADIA; MATTIAZZI ALICIA; SANTALLA MANUELA; FERRERO PAOLA; BALCAZAR DARÍO; VALVERDE CARLOS

Buenos Aires

Congreso; Reunión conjunta de sociedades biomédicas; 2017

SAFIS

Tabaquism is a chronic disease caused by nicotine addiction, being responsible for about 40.000 deaths/ year in Argentine. Cardiovascular effects include coronary heart disease, acute myocardial infarction and congenital cardiomyopathy. The fruit fly Drosophila melanogaster is a well-known model used to study several human diseases and addictions. The possibility to edit its genome, to produce transgenic lines and to study the interaction between genes and the environment, make this organism an alternative to study a possible relationship between genes and tobacco effects. We developed an experimental approach of ?chronic consuming-cigarette? flies simulating active human smoking. We compared the cardiac function of smoking flies (S) vs. non-smoking controls (C). Tobacco increased heart rate (beats/min: S: 155.5 ±14.6 n=6, C: 105.8±6.9 n=12), reduced Ca2+ transient amplitude (arbitrary units of fluorescence: S: 1.27±0.2 n=10, C: 0.25±0.05 n=7), time of to peak contraction (TTP S: 0.16±0.01 sec n=12, S: 0.12±0.01 sec n= 5) and relaxation time (t1/2 S: 0.12±0.01 sec n=12, C: 0.07±0.02 sec n=5). Similar results were obtained with nicotine alone, in semi-intac preparation. Together, our evidences suggest that nicotine is the principal component of tobacco that induces cardiac changes in the fly?s adult heart. Current experiments are exploring receptors and signaling pathways involved in nicotine action on heart function. D. melanogaster presents glutamatergic and beta like-adrenergic receptors, associated to nervous terminals reaching the heart. Moreover, nicotinic receptors (nAChR) could be present in cardiac Drosophila muscles. We detected nAChR1 in adult total extract of protein of D. melanogaster using the antibody against human nAChR1. Assays in course are orientated to determinate the contribution of these three types of receptor activation to the nicotine effects on cardiac activity.Key words: Tabaquism; Nicotine; Drosophila melanogaster; Cardiac alterations; Nicotinic receptors.