Understanding the aging cardiovascular system

Wei, Jeanne Y.

doi:10.1111/j.1447-0594.2004.00235.x

Cited by 10 publications

(13 citation statements)

References 81 publications

(253 reference statements)

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“…Increased collagen concentration of the heart causes increased ventricular stiffness, reduced ventricular compliance and impaired diastolic function of the heart, which is a very common problem in the elderly 2-4, 46-50. There have been few studies of cardiac function in the Ames dwarf mice.…”

Section: Discussionmentioning

confidence: 99%

“…Arrythymogenic death in mice would be difficult to detect but an indication that it might be important is provided by recent studies of arrhythmias induced in mouse hearts with fibrosis (Stein et al, 2010). The Ames mice with their extended life-expectancy might also have a diminished tendency to develop cardiac pathology which contributes to early morbidity 2-4.…”

Section: Introductionmentioning

confidence: 99%

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Smaller cardiac cell size and reduced extra-cellular collagen might be beneficial for hearts of Ames dwarf mice

Helms¹,

Azhar²,

Zuo³

et al. 2010

Int. J. Biol. Sci.

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Purpose: To test the hypothesis that cardiac morphologic differences between Ames dwarf and wild-type littermates might correlate with the increased longevity observed in the Ames dwarf mice.Methods: Hearts removed from young adult (5-7 mo) and old (24-28 mo) Ames dwarf and wild-type littermates underwent histological and morphometric analysis. Measurements of cell size, nuclear size, and collagen content were made using computerized color deconvolution and particle analysis methodology.Results: In the young mice at six months of age, mean cardiomyocyte area was 46% less in Ames dwarf than in wild-type mice (p<0.0001). Cardiomyocyte size increased with age by about 52% in the wild-type mice and 44% in the Ames dwarf mice (p<0.001). There was no difference in nuclear size of the cardiomyocytes between the young adult wild-type and Ames dwarf mice. There was an age-associated increase in the cardiomyocyte nuclear size by approximately 50% in both the Ames and wild-type mice (p<0.001). The older Ames dwarf mice had slightly larger cardiomyocyte nuclei compared to wild-type (2%, p<0.05). The collagen content of the hearts in young adult Ames dwarf mice was estimated to be 57% less compared to wild-type littermates (p<0.05). Although collagen content of both Ames dwarf and wild-type mouse hearts increased with age, there was no significant difference at 24 months.Conclusions: In wild-type and Ames dwarf mice, nuclear size, cardiomyocyte size, and collagen content increased with advancing age. While cardiomyocyte size was much reduced in young and old Ames dwarf mice compared with wild-type, collagen content was reduced only in the young adult mice. Taken together, these findings suggest that Ames dwarf mice may receive some longevity benefit from the reduced cardiomyocyte cell size and a period of reduced collagen content in the heart during adulthood.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Smaller cardiac cell size and reduced extra-cellular collagen might be beneficial for hearts of Ames dwarf mice

Helms¹,

Azhar²,

Zuo³

et al. 2010

Int. J. Biol. Sci.

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“…For example, with increasing age there is impairment in left ventricular systolic reserve capacity and in diastolic filling (34) as well as blunted inotropic and chronotropic responses to certain ␤-adrenergic agonists (26). A decline in myocardial vasodilator capacity, predominantly through endothelial-dependent mechanisms that are distinct from epicardial involvement by coronary atherosclerosis, is present in both experimental models of aging and in older humans (3,9,12,14,22,32).…”

mentioning

confidence: 99%

Impact of aging on myocardial metabolic response to dobutamine

Soto¹,

Herrero²,

Kates³

et al. 2003

American Journal of Physiology-Heart and Circulatory Physiology

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of aging on myocardial metabolic response to dobutamine. Am J Physiol Heart Circ Physiol 285: H2158-H2164, 2003. First published July 24, 2003 10.1152/ajpheart.00086. 2003.-In humans, under resting conditions there is an agerelated decrease in myocardial fatty acid utilization (MFAU) and oxidation (MFAO) and a relative increase in myocardial glucose utilization (MGU). The impact of age on an individual's myocardial metabolic response to catecholamines is not well defined. Sixteen younger (mean age, 26 Ϯ 5 yr) and 14 older (mean age, 69 Ϯ 4 yr) volunteers underwent positron emission tomography to measure myocardial blood flow, myocardial oxygen consumption (MV O2), MFAU, MFAO, and MGU both under resting conditions and during dobutamine infusion. In response to dobutamine administration, the ratepressure product, myocardial blood flow, and MV O2 measurements increased by similar amounts in both groups. No age-related differences were noted in the responses of plasma insulin, glucose, fatty acid, or lactate levels to dobutamine. With dobutamine infusion, MFAU and MFAO increased by a similar extent in both younger and older volunteers (age/ dobutamine interactions, P ϭ 0.62 and 0.75, respectively). In contrast, MGU increased with dobutamine administration in the younger (from 149 Ϯ 71 to 209 Ϯ 78 nmol ⅐ g Ϫ1 ⅐ min Ϫ1 ; P ϭ 0.04) but not in the older (from 235 Ϯ 147 to 176 Ϯ 84 nmol ⅐ g Ϫ1 ⅐ min Ϫ1 ; P ϭ 0.23; age/dobutamine interaction, P ϭ 0.03) group. With dobutamine infusion, hearts in both younger and older volunteers responded by increasing their MFAU and MFAO values. Whereas younger hearts also responded with an increase in MGU, older hearts did not. Although the clinical significance of these findings awaits further study, these results may partially explain the impaired contractile reserve and the increased incidence of cardiovascular disease in older individuals. fatty acids; glucose; oxidation; heart; catecholamine CARDIOVASCULAR DISEASE IS a primary cause of death and disability in Americans 65 yr of age or older (2). The prevalence of a variety of cardiac disorders including atherosclerosis, atrial fibrillation, heart failure, and hypertension increases with age (1). Moreover, because of the effects of aging on the heart, the clinical manifestations of these disorders are more pronounced in older patients than in younger ones. Consequently, it is important to better delineate the effects of aging on the heart to potentially reduce both the incidence and the impact of various disorders that are specific to the cardiovascular system.Aging has numerous deleterious effects on the heart. For example, with increasing age there is impairment in left ventricular systolic reserve capacity and in diastolic filling (34) as well as blunted inotropic and chronotropic responses to certain ␤-adrenergic agonists (26). A decline in myocardial vasodilator capacity, predominantly through endothelial-dependent mechanisms that are distinct from epicardial involvement by coronary atherosclerosis, is present in both experime...

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“…Nevertheless, mortality in older patients was almost twice that among the younger group. This could be explained in part by the comorbidities present in the elderly population, in part by the agerelated changes in the cardiovascular system [25]. The multivariate analysis showed older age and PCI failure to be independent predictors of in-hospital death.…”

Section: Discussionmentioning

confidence: 85%