Examination of alpha 1 adrenoceptor subtypes in the human ureter

Urinary stone disease is a common condition affecting up to 12% of the population. Speedy elimination of ureterolithiasis in the lower part of ureters is reported with the alpha 1-blocker. This study was carried out to characterize the alpha 1 adrenoceptors (AR) subtype gene and protein expression in the proximal, medial, and distal regions of the human ureter with the aim of facilitating stone expulsion.

The study was carried out on 20 volunteers. Proximal, medial and distal ureter specimens were obtained as discarded tissues after nephroureterectomy for renal pelvic or ureteral carcinoma. Proximal ureter specimens were obtained as discarded tissues after nephrectomy for renal carcinoma. Using ureter samples, real-time reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemical staining were performed.

The alpha 1d subtype mRNA was highly expressed in each ureteral region, accounting for about 54% of the total AR Messenger Ribonucleic Acid. In the proximal and medial ureter, the distribution of ARs was alpha 1d > or = alpha 1a > alpha 1b as well as that of the total ureter. The distal ureter expressed the highest amount of alpha 1d ARs. The alpha 1d subtype expression tended to be high compared with the alpha 1a subtype expression. In the distal ureter, the distribution of ARs was alpha 1d > alpha 1a > alpha 1b. Immunohistochemical staining revealed that expressions of alpha 1a-AR and alpha 1d-AR were higher than that of alpha 1b-AR.

According to our results, we should try the alpha 1d AR antagonist for the conservative expulsive therapy of distal ureteral stones in the highest region of alpha 1d subtype distribution.