title: Direct effect of acebutolol on force generation in immature and adult myocardium.
abstract: The effect of acebutolol on active isometric force generation has been studied in isolated papillary muscle preparations from adult cats and kittens less than 24 h old. Statistically significant reduction in active force occurred at a concentration of 0.27 mmol-litre-1 in the adult preparations and at 1.34 mmol-litre-1 in the infant ones. At 2.86 mmol-litre-1 active force had fallen to 43.4%+/-2.2 (SEM) of the control value in the adults and to 52.4%+/-3.3(SEM) in the infants. These results suggest that the infant myocardium is no more sensitive to the negative inotropic effect of acebutolol than is the adult myocardium.
mesh_terms: D000070:Acebutolol / Q000494:pharmacology*; D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D002415:Cats; D003864:Depression, Chemical; D004305:Dose-Response Relationship, Drug; D006321:Heart / Q000254:growth & development; D066298:In Vitro Techniques; D009200:Myocardial Contraction / Q000187:drug effects*; D010210:Papillary Muscles / Q000187:drug effects
chemical_list: D000070:Acebutolol