scholarly journals Biochemical and Molecular Aspects of Vascular Adrenergic Regulation of Blood Pressure in the Elderly

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
William E. Schutzer ◽  
Scott L. Mader

Hypertension, orthostatic hypotension, arterial insufficiency, and atherosclerosis are common disorders in the elderly that lead to significant morbidity and mortality. One common factor to these conditions is an age-related decline in vascular beta-adrenergic receptor-mediated function and subsequent cAMP generation. Presently, there is no single cellular factor that can explain this age-related decline, and thus, the primary cause of this homeostatic imbalance is yet to be identified. However, the etiology is clearly associated with an age-related change in the ability of beta-adrenergic receptor to respond to agonist at the cellular level in the vasculature. This paper will review what is presently understood regarding the molecular and biochemical basis of age-impaired beta-adrenergic receptor-mediated signaling. A fundamental understanding of whyβ-AR-mediated vasorelaxation is impaired with age will provide new insights and innovative strategies for the management of multiple clinical disorders.

1991 ◽  
Vol 71 (6) ◽  
pp. 2094-2098 ◽  
Author(s):  
S. L. Mader ◽  
C. L. Downing ◽  
E. Van Lunteren

Previous reports suggest that hypoxia downregulates cardiac beta-adrenergic receptors from young rats. Because aging alters response to stress, we hypothesized an age-related alteration in the response to hypoxia. Male Fischer-344 rats, aged 3 and 20 mo, were divided into control and hypoxic groups. The hypoxic rats were exposed to hypobaric hypoxia (0.5 atm) for 3 wk. After hypoxic exposure, body weight decreased, hematocrit increased, right ventricular weight increased, and left ventricular weight decreased in all animals. beta-Adrenergic receptor density declined after hypoxic exposure in the young but not in the older animals, a change that was confined to the left ventricle. beta-Adrenergic receptor density in the right ventricle was significantly lower in the older animals than in the young animals. Plasma catecholamines (norepinephrine, epinephrine) drawn after the animals were killed (stress levels) decreased in young rats and increased in old rats after the exposure to hypoxia. Hypoxia is a useful physiological stress that elucidates age-related changes in cardiac beta-adrenergic receptor and catecholamine regulation that have not previously been described.


2008 ◽  
Vol 3 (3) ◽  
pp. 174-184 ◽  
Author(s):  
Carlos Taira ◽  
Andrea Carranza ◽  
Marcos Mayer ◽  
Carla Di Verniero ◽  
Javier Opezzo ◽  
...  

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