Producción CyT
Congreso
Autoría
Tula, Marina Luz
;
Altamirano, Fernando Gabriel
;
LACOSTE, MARIA GABRIELA
;
Castro Pascual, Ivanna Carla
;
Anzulovich, Ana Cecilia
;
Ferramola, Mariana Lucila
Fecha
2019
Editorial y Lugar de Edición
-
ISSN
1667-5746
Resumen
Información suministrada por el agente en
SIGEVA
Aging has been extensively associated with a decline in cardiovascular performance and an increased risk of cardiovascular diseases, such as atherosclerosis, hypertension and myocardial infarction. Additionally, the circadian system coordinates and synchronizes numerous physiological processes, including cardiovascular function. The performance of this system is also disrupted with aging. On the other hand, caloric restriction (CR) has been recognized as a preventive factor for atherosclerosis ...
Aging has been extensively associated with a decline in cardiovascular performance and an increased risk of cardiovascular diseases, such as atherosclerosis, hypertension and myocardial infarction. Additionally, the circadian system coordinates and synchronizes numerous physiological processes, including cardiovascular function. The performance of this system is also disrupted with aging. On the other hand, caloric restriction (CR) has been recognized as a preventive factor for atherosclerosis and vascular aging. In the present study, we aimed to evaluate if the circadian variation of the blood pressure (BP) and BMAL1 protein levels are altered in the heart of aged rats and aged rats under CR. Holtzman 3- and 22-month old male rats and 22-month old male rats under 3 months of 40% of CR were maintained in constant darkness conditions for 15 days, in order to study the endogenous rhythms. Blood pressure was determined under 12h/12h light/dark (LD) conditions, as well as under 12h/12h dark/dark (DD) conditions. Young rats subjected to LD conditions showed a circadian variation in systolic BP (SBP) and diastolic BP (DBP) (rhythm percentage 47.4% and 20.54%, respectively). Under the same conditions, SBP and DBP underwent a loss of circadian oscillation in aged rats. When aged rats were subjected to CR, we observed a restoration of the circadian variation and a phase advancement of SBP and DBP, in comparison to young animals (p<0.0001 and p< 0.01, respectively). On the other hand, in DD conditions, all three groups of animals showed a circadian oscillation in SBP values (rhythm percentage 27.27% in young, 35.52% in aged and 33% in aged subjected to CR). We also observed that aged rats presented a higher rhythm?s amplitude than young animals (p<0.05). DBP values in DD, also varied in a circadian way in young and aged rats (rhythm percentage 24.57% and 20.94%, respectively), showing the last group, a decrease in the rhythm?s mesor and a phase advancement when compared to young rats (p<0.01 and p<0.05, respectively). The rhythmicity of DBP was lost in aged rats under CR. In previous studies, we observed that BMAL1 protein levels vary in a 24-hour period in the heart of young and aged rats. In the present work, we observed that BMAL1 protein levels present a circadian oscillation in the heart of aged rats under CR, with a decrease in the rhythm?s mesor, an increase in the rhythm?s amplitude and a phase advancement when compared to de young rats (p<0.001, p<0.001 and p<0.05, respectively). In this work, we observed how the circadian rhythm of BP values and BMAL1 protein levels are altered the in heart during aging. CR modifies these alterations, restoring the circadian oscillation of some parameters in old rats. Further research needs to be done in order to elucidate the possible positive impact of the CR on the altered circadian and cardiovascular systems in elderly individuals.
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Palabras Clave
CALORIC RESTRICTIONAGINGBLOOD PRESSUREHEARTCIRCADIAN RHYTHMS