title: Effect of xamoterol, a beta 1-adrenoceptor partial agonist, on myocardial pH decreased by coronary occlusion in dogs.
abstract: The effect of xamoterol on ischemic myocardial pH was examined in dogs. Partial occlusion of the left anterior descending coronary artery (LAD) decreased myocardial pH from 7.52-7.63 to 6.80-6.85. Xamoterol was injected intravenously 30 min after LAD occlusion that lasted for 90 min. Xamoterol (30 or 70 micrograms/kg) increased the myocardial pH that had been decreased by partial occlusion, the degree of pH increase being greater with 30 micrograms/kg than with 70 micrograms/kg, but at the dose of 200 micrograms/kg it did not increase. In the nonischemic normal heart, xamoterol (30 or 70 micrograms/kg, i.v.) had no marked effect on hemodynamic parameters, but the drug (200 micrograms/kg, i.v.) increased contractile force and heart rate with a transient decrease of myocardial pH. It is concluded that only the small dose (30 or 70 micrograms/kg) of xamoterol is effective in restoring the myocardial pH that has been decreased by partial occlusion of the LAD.
mesh_terms: D000318:Adrenergic beta-Agonists / Q000627:therapeutic use*; D000818:Animals; D003326:Coronary Circulation / Q000187:drug effects; D003327:Coronary Disease / Q000188:drug therapy*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D011412:Propanolamines / Q000627:therapeutic use*; D017307:Xamoterol
chemical_list: D000318:Adrenergic beta-Agonists; D011412:Propanolamines; D017307:Xamoterol