Uterine relaxation by clenbuterol and fenoterol in conscious rats.
The uterine relaxant activity of clenbuterol and fenoterol was compared in conscious non-pregnant rats with chronically implanted uterine catheters. 0.001-0.020 mg/kg clenbuterol i.v. significantly reduced uterine motility, duration of action exceeded the observation period of 30 min. After oral administration nearly identical doses were needed for comparable effects. Following intravenous administration, 0.005 mg/kg fenoterol induced uterine relaxation, but in contrast to clenbuterol, duration of action was short. After oral administration relatively high doses of 1 and 5 mg/kg were needed for reduction of uterine motility. These results may encourage the use of clenbuterol in obstetric practice. They enlarge the basis for the evaluation of pharmacological findings obtained with fenoterol and clenbuterol.
D000284:Administration, Oral; D000818:Animals; D002976:Clenbuterol / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004983:Ethanolamines / Q000494:pharmacology*; D005260:Female; D005280:Fenoterol / Q000494:pharmacology*; D007275:Injections, Intravenous; D009126:Muscle Relaxation / Q000187:drug effects; D051381:Rats; D014590:Uterine Contraction / Q000187:drug effects*
D004983:Ethanolamines; D005280:Fenoterol; D002976:Clenbuterol