Effects of age on cardiovascular responses to adrenaline in man
| Autor: | F. H. H. Leenen, Michel White |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1997 |
| Předmět: |
Cardiac function curve
Adult Male medicine.medical_specialty Aging Epinephrine Ganglionic Blockers Blood Pressure Baroreflex Norepinephrine Catheters Indwelling Sex Factors Heart Rate Isoprenaline Internal medicine Heart rate medicine Humans Pharmacology (medical) Drug Interactions skin and connective tissue diseases Infusions Intravenous Aged Pharmacology Analysis of Variance Ejection fraction business.industry Hemodynamics Stroke Volume Stroke volume Original Articles Adrenergic beta-Agonists Middle Aged Endocrinology Blood pressure Echocardiography Trimetaphan camsilate Female sense organs business Trimethaphan medicine.drug |
| Popis: | Aims Whereas the effects of ageing on β-receptor mediated responses have been extensively studied in vitro and in vivo using the β-adrenoceptor agonist isoprenaline, little is known regarding ageing induced changes in responses to endogenous catecholamines. In the present study, we assessed age-related changes in cardiac responses to the endogenous β-adrenoceptor agonist adrenaline and the influence of age-related changes in arterial baroreflex function on these responses. Methods Adrenaline alone was infused in 14 young subjects, age 30±2 years (eight males, six females), and 18 older subjects (six males, 12 females), age 60±2 years, and together with ganglionic blockade (trimetaphan) in seven young and 11 older subjects. Adrenaline was infused at 3–4 incremental rates, each rate for 8 min. Cardiac function was assessed by echocardiography. Results Adrenaline alone, at infusion rates 20–160 ng kg−1 min−1 caused similar increases in heart rate in the two groups. In contrast, adrenaline caused larger increases in stroke volume, ejection fraction, cardiac index and systolic blood pressure and larger decreases in end-systolic wall stress and diastolic blood pressure in the young compared with older subjects. Older females exhibited the smallest increases in stroke volume index and ejection fraction. With concomitant ganglionic blockade, all above cardiovascular responses to adrenaline were similar in the young and older group. Plasma adrenaline increased similarly in the two groups. Conclusions We conclude that ganglionic blockade does not unmask an age-related decrease in cardiovascular responses to adrenaline (in contrast to isoprenaline). A concomitant ageing induced decrease in neuronal uptake (which applies to adrenaline, but not isoprenaline) may explain such a differential effect.. |
| Databáze: | OpenAIRE |
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