Dopamine D1and D2receptors in the human ureter and urinary bladder: a radioligand binding and autoradiographic study

Abstract

ObjectiveTo analyse the pharmacological profile and the anatomical localization of the dopamine D, and D, receptors in sections of the pelvic part of the ureter and of the fundus of the urinary bladder.Patients, materials and methodsSamples of the pelvic part of the ureter and of the fundus of the urinary bladder were taken in men (age range 61k4 years) who were undergoing lower urinary tract surgery. Biochemical characterization and autoradiographical techniques were used on frozen sections of the ureter or the urinary bladder. [3H]‐SCH 23390 was used as a ligand of dopamine D, receptors and [3H]‐spiroperido1 as a ligand of dopamine D2 receptors.Results[3H]‐SCH 2 3 390 and [3H]‐spiroperidol were bound by specific sections of the ureter and of the urinary bladder. The pharmacological profile of the binding was consistent with the labelling of D, and D, receptors respectively. Light microscope analysis of the localization of D1 and D2 receptors revealed the accumulation of the two radioligands in the tunica muscularis of the ureter or of the urinary bladder. Conclusion A possible role of the dopaminergic system in the control of urine flow and of some dysfunctions of the lower urinary tract is suggested.