S. D. Gokhale, M. M. Bensreti
Department of Pharmacology, Faculty of Medicine, University of Garyounis, Benghazi, S. P. L.A. J.
Garyounis Medical Journal Vol. 1, No.2. July 1978:23-25
The effect of adrenaline, noradrenaline, phenylephrine and isopropylnoradrenaline on the isolated rat ileum was examined under different experimental conditions. In control experiments isopropylnoradrenaline, adrenaline, noradrenaline and phenylephrine produced a relaxation in that order of potency. In preparations pretreated with phenoxybenzamine (1 x 10 for 90 mm) phenylephrine had no effect, but the other drugs produced a relaxation. The relaxation following noradrenaline was similar in magnitude to that following adrenaline but isopropylnoradrenaline was more effective. In preparation pretreated with propranolol (1 x 106 for 10 mi, isopropylnoradrenaline had no effect but adrenaline, noradrenaline and phenylephrine produced a relaxation in that order of potency.
Our results support the classification of intestinal adrenoceptors into alpha and beta, both subserving relaxation with the additional suggestion that in the rat the intestinal beta receptors are likely to be of the beta1 type.
Keywords: Some Observations on the Responses of the Isolated Rat ileum to Adrenaline, Noradrenaline, Phenylephrine and Isopropyl-Noradrenaline and Their Modification by Phenoxy-Benzamine and Propranolol