IQUIMEFA   05518
INSTITUTO QUIMICA Y METABOLISMO DEL FARMACO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Aging in thyroid dysfunction: are caveolins involved in the cardiovascular nitric oxide production?.
Autor/es:
SARATI LORENA IVONNE; MARTINEZ CARLA; ARTES NICOLAS; BALASZCZUK ANA MARÍA; FELLET ANDREA
Lugar:
Milan
Reunión:
Congreso; 21 St European Meeting on Hypertension and Cardiovascular Prevention; 2011
Institución organizadora:
21 St European Meeting on Hypertension and Cardiovascular Prevention
Resumen:
Aging in thyroid disfunction: are caveolins proteins involved in the cardiovascular nitric oxide production? Sarati L, Martinez, Artés N, Balaszczuk A, Fellet A. Department of Physiology, School of Pharmacy and Biochemistry; University of Buenos Aires. IQUIMEFA, CONICET. Objective: Caveolins, the structural proteins of caveolae, modulate numerous signaling pathways including nitric oxide (NO) production. Among the caveolin family, caveolin (cav) -1 and -3 are mainly expressed in endothelial and muscle cells, respectively. In this study, we investigate whether (i) changes in caveolins abundance occur during cardiac aging in thyroid dysfunction, and (ii) the process could influence NO synthase (NOS) activity. Methods:  We studied protein levels of cav -1 and 3 (by western blot (UA)) and NOS activity (by conversion of [14C (U)]?L-arginine to [14C (U)]?L-citrulline (pmol.103/g.h)) in right atria (A), left ventricle (V) and aorta (AO) tissues in 2-mo-old and 12-mo-old euthyroid (Eu), hyperthyrpoid (H) and hypothyroid (h) rats. Data are mean ± S.E.M. One way analysis of variance (ANOVA) followed by post-hoc Tamhane test or Student?s t test was used for multiple comparisons. The 5% probability level was used as a criterion for significance.  Results:  A NOS activity in Eu decreased with aging (20,22±0,61 vs 5,10±0,30*) and it was associated with an increased of cav-1 and 3 (1,27±0,02 vs 1,72±0,01*; 0,391±0,01 vs 0,662±0,01*). NOS activity in H rats did not change with aging (1,47±0,30 vs 1,58±0,40); h rats showed an increased of it with aging (0,29±0,15 vs 1,47±0,21*) . In both groups cav -1 showed an increased (H:1,35±0,02 vs 1,96±0,01*; h:1,82±0,01 vs 2,51±0,03*) with aging but cav-3 did not change. V showed an increased of NOS activity with aging in all experimental group (Eu 0,15±0,07 vs 1,63±0,1*; H 2,15±0,07 vs 2,56±0,05*; h 2,47±0,13 vs 4,40±0,18*). This result was asociated with a decreased of cav-1 (Eu 1,58±0,01 vs 1,04±0,01*; H 1,44±0,04 vs 1,24±0,01*; h 1,7±0,02 vs 1,28±0,02*) and cav-3 (Eu 1,61±0,02 vs 0,46±0,04*; H 0,953±0,02 vs 0,52±0,01*; h 0,912±0,03 vs 0,664±0,02*). AO NOS activity decreased with aging in all experimental groups, (Eu 1,78±0,07 vs 0,16±0,06*; H 3,37±0,2 vs 0,40±0,06*; h 2,01±0,06 vs 0,54 ±0,04*). Eu rats did not change protein levels of cav-1 with aging but decreased cav-3 (1,4±0,02 vs 0,85±0,03*). Cav-1 and cav-3 increased in H (1.2±0,02 vs 1,64±0,01*; 0 vs 0,153±0,02*) . h rats had increased cav-1 with aging (1,24±0,03 vs 1,49±0,04*) but decreased cav- 3 (2,07±0,05 vs 1,38±0,02*). Conclusion: cardiovascular NO production is affected by aging, and thyroid hormones have an important and differential role of enzyme activity modulators. The actions of the latter seem to be tissue specific.