SUPER-SENSITIVITY OF THE RAT URINARY-BLADDER FOLLOWING CHEMICAL SYMPATHECTOMY

Abstract

6-Hydroxydopamine (100 mg/kg i.v. injected twice in a weekly interval) was used for the destruction of the adrenergic nerves in the rat detrusor muscle. Two to three weeks after the 1st injection of this substance the sensitivity of the detrusor muscle to parasympathomimetic and sympathomimetic drugs was tested by recording the intravesical pressure in situ. The sensitivity to methacholine was unchanged, whereas a supersensitivity to noradrenaline [norepinephrine], adrenaline [epinephrine], phenylephrine and isoprenaline had developed, involving .alpha.-adrenoceptor mediated contraction and .beta.-adrenoceptor mediated relaxation. The supersensitivity was of the postjunctional type.