Effect of cocaine and other drugs on sensitivity of the estrogen-dominated isthmus of rabbit oviduct to noradrenaline.
The influence of the adrenergic innervation on the magnitude of responses of the isthmus of rabbit oviduct to (-)-noradrenaline was examined. Tissues were obtained from estrogen-dominated animals, and isometric contractions of longitudinal and circular muscle layers separately recorded. Longitudinal muscle was significantly more sensitive to (-)-noradrenaline. Cocaine potentiated responses of both corcular and longitudinal muscle to (-)-noradrenaline, circular muscle being more potentiated. Similar results were obtained with desipramine. Tissues obtained from 6-hydroxydopamine pretreated animals did not respond to tyramine, and longitudinal and circular muscles were equisensitive to (-)-noradrenaline. Cocaine did not potentiate responses to (-)-noradrenaline in such tissues. Responses to (-)-noradrenaline were not altered by propranolol, hydrocortisone, or oxytetracycline. It was concluded that responses resulted from a predominant effect on alpha-receptors. The magnitude of responses to (-)-noradrenaline was mainly influenced by neuronal uptake of amine. Indirect evidence was obtained for a greater degree of adrenergic innervation to the circular muscle layer of the isthmus, in keeping with histological studies.
D000818:Animals; D003042:Cocaine / Q000494:pharmacology*; D004967:Estrogens / Q000502:physiology*; D005187:Fallopian Tubes / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D006892:Hydroxydopamines / Q000494:pharmacology; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009638:Norepinephrine / Q000378:metabolism / Q000494:pharmacology*; D011433:Propranolol / Q000494:pharmacology; D011817:Rabbits; D013564:Sympathetic Nervous System / Q000502:physiology
D004967:Estrogens; D006892:Hydroxydopamines; D011433:Propranolol; D003042:Cocaine; D009638:Norepinephrine