ADRENERGIC BLOCKADE PRODUCED BY THE DICHLORO ANALOGS OF EPINEPHRINE, ARTERENOL AND ISOPROTERENOL

¹ Department of Pharmacology, Medical College of Georgia, Augusta, Georgia

The intestinal inhibitory responses in the dog produced by isoproterenol were blocked by DCI. This blocking effect of DCI is shared to a lesser extent by DCE and to an even lesser extent by D CA. The depressor response to isoproterenol was reduced by pretreatment with DCI, DCE and DCA.

The intestinal inhibitory responses produced by epinephrine and levarterenol were not reduced by DCI, DCE or DCA. The pressor responses to epinephrine and levarterenol were slightly prolonged after DCI but were not significantly altered after DCE or DCA in the doses tested.

Intestinal inhibition produced by Win 277, Win 3046 and nylidrin were blocked after pretreatment with DCI. The depressor responses to Win 277, Win 3046 and nylidrin were reduced but not completely abolished after DCI.

Intestinal inhibition produced by Butanephrine was markedly reduced after DCI and was completely abolished after DCI plus Dibozane. The depressor response to Butanephrine was converted to a pressor response after DCI and then back to a depressor response after Dibozane.

Intestinal inhibition produced by methoxamine, metaraminol, Paredrine and ephedrine was not blocked by I) CI but was completely abolished after I) ibozane. After DCI the pressor responses to all of these drugs were not significantly altered.