PERIPHERAL VASCULAR EFFECTS OF CYCLOPROPANE AND HALOTHANE IN THE DOG

¹ Department of Anesthesiology, University of Oklahoma School of Medicine, Oklahoma City, Oklahoma

Measurements of vascular resistance were obtained in isolated organs during administration of anesthetic gases. Cyclopropane (C₃H₆) was administered to the dog via the lungs (remote plus local effects) or only to the isolated, constant-flow-perfused forelimb via an excised lung (local effect) in concentrations of 10 to 30%. Halothane was similarly given in concentrations of 1 to 4%. C₃H₆ and halothane were also tested in a dog-pump-muscle or a dog-pump-skin (hindpaw) preparation and in an oxygenator-muscle-skin setup. Data indicate that C₃H₆, administered systemically, increases resistance in skeletal muscle, lowers resistance in skin and decreases total resistance in the whole forelimb. The effect of local administration of C₃H₆ is also to increase resistance in skeletal muscle and lower it in skin. Total forelimb resistance is not consistently altered. Systemic or local administration of halothane causes a fall in resistance in skin, muscle and forelimb vasculatures.