Abstract
The present study is concerned with general characteristics of strips of dog femoral artery as pharmacological test objects and with the responses of such strips to drugs. The spirally cut strips of dog femoral artery possessed a small amount of spontaneous tone and never exhibited rhythmic contractions. When strips were first attached to a lever under 4 g tension, they underwent a gradual elongation and increased in sensitivity to stimulating drugs over a period of about 1.5 to 3 hr. Once maximal sensitivity had been attained, the response to stimulating drugs usually remained constant for 7 hr. When effects of adrenergic drugs, such as noradrenaline, isoprenaline, dopamine, tyramine and ephedrine were tested, Krebs-bicarbonate solution containing NaHS03 was used in order to inhibit oxidation of amines in the solution. All drugs except isoprenaline produced contractions which were inhibited completely by phenoxybenzamine. Isoprenaline showed biphasic effects, i.e., relaxation in low concentration and contraction in high concentration. The former relaxation was inhibited by propranolol and the latter contraction by phenoxybenzamine, but acetylcholine, at any concentration, caused relaxation which was blocked by atropine. As strips of dog femoral artery respond to drugs in a manner similar to in vivo experiments, femoral arterial strips of dogs make for good pharmacological test objects.
