Age-Related Changes of Cardiac Caveolins and Nitric Oxide Synthase Modulation during Hypovolemic State

Background Nitric Oxide (NO) is one of the factors activated by hypovolemic state. Caveolins might affect the production of NO with increasing age. ObjectiveTo investigate the interaction between caveolin-1 (cav-1) and endothelial nitric oxide synthase (eNOS) in the ventricles of young and adult rats subjected to acute bleeding. Material and MethodsWe used young (2 months old) and adult (12 months old) male Sprague-Dawley rats. The animals from each age group (young and adult) were divided into two experimental groups: Control: control group, and Hem: bleeding group (20% of blood volume). The animals were sacrificed and the left ventricle was resected.ResultsAfter bleeding, NOS activity increased by 21% and 45% in young rats and by 32% and 56% in adult rats. Western blot analysis revealed that NOS levels were lower (31%) in adult rats. Sixty minutes after bleeding, eNOS activity increased by 147% in young animals and by 66% in adults, with lower increase at 120 minutes. Colocalization showed a diffuse pattern of eNOS location associated with cav-1 in group Control of young animals. A dissociation pattern was observed in group Hem at 60 min which was partially restored at 120 min. The dissociation pattern of eNOS and cav-1 in group Control adult animals was greater compared to that of young rats. This characteristic was also seen after 60 min and 120 min. ConclusionThe increased production of NO during hypovolemic state depends on the presence of cav-1 which plays a key role in the aging process.Introducción El óxido nítrico (NO) es uno de los factores que se estimulan durante el estado hipovolémico.Las caveolinas afectarían la producción de NO en el corazón según avanza la edad.ObjetivoInvestigar la interacción entre la caveolina-1 (cav-1) y la óxido nítrico sintetasa endotelial (eNOS) en ventrículos de ratas jóvenes y adultas sometidas a hemorragia aguda.Material y métodosSe utilizaron ratas Sprague-Dawley machos jóvenes (2 meses de edad) y adultas (12 meses de edad). Se conformaron dos grupos experimentales de cada grupo etario (jóvenes y adultas): Control y Hemo (sangrado: 20% de la volemia). Los animales se sacrificaron para la extracción del ventrículo izquierdo.Resultados Luego del sangrado, la actividad de la NOS aumentó el 21% y el 45% en ratas jóvenes y el 32% y el 56% en adultas. El Western blot reveló que los niveles de eNOS fueron menores (31%) en ratas adultas. La hemorragia ocasionó un aumento del 147% de la eNOS a los 60 min en animales jóvenes y del 66% en adultos, atenuándose a los 120 min