[Age-related changes in inotropic effects of noradrenaline and acetylcholine on the myocardium of guinea pigs].
The inotropic effects of noradrenaline (10(-7)-10(-5) M) and acetylcholine (10(-8)-10(-6) M) were studied in experiments carried out on preparations of the right atria and on papillary muscles of the right ventricle in adult (4-5 months) and old (18-24 months) guinea pigs. An age-related decrease in inotropic noradrenaline effects and the displacement of dose-effect relationships to the right was revealed. Similar changes of the dose-related effects of acetylcholine superfused against the background of noradrenaline action were observed. The direct inotropic action of the acetylcholine did not change with ageing. A lack of the essential atrial-ventricular differences in age-related changes in myocardial reactivity is apparently very significant for support of effective functional coupling of cardiac chambers in ageing.
Kaz'min
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Dudka
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D000109:Acetylcholine / Q000494:pharmacology*; D000375:Aging / Q000502:physiology*; D000818:Animals; D016275:Atrial Function; D003470:Culture Media; D003864:Depression, Chemical; D006168:Guinea Pigs; D006325:Heart Atria / Q000187:drug effects; D006352:Heart Ventricles / Q000187:drug effects; D066298:In Vitro Techniques; D008955:Models, Cardiovascular; D009200:Myocardial Contraction / Q000187:drug effects / Q000502:physiology*; D009638:Norepinephrine / Q000494:pharmacology*; D010210:Papillary Muscles / Q000187:drug effects / Q000502:physiology*; D016276:Ventricular Function
D003470:Culture Media; D000109:Acetylcholine; D009638:Norepinephrine
Starechi zminy inotropnoï diï noradrenalinu ta atsetylkholinu na miokard mors'kykh svynok.