Mitochondrial DNA deletion of the human detrusor after partial bladder outlet obstruction - Correlation with urodynamic analysis

Objectives. To investigate mitochondrial DNA (mtDNA) mutations in human det rusor after partial bladder outlet obstruction (BOO) and correlate the find ings with the results of urodynamic studies. Methods. Sixty-two male patients with and without BOO were recruited and as sessed by the International Prostate Symptom Score, a quality-of-life asses sment index, and sonography. The severity of partial BOO was determined by pressure-flow study With an International Continence Society (ICS) nomogram . Random detrusor biopsies obtained cystoscopically were analyzed by polyme rase chain reaction (PCR) techniques to detect possible mtDNA deletions. Pr imer-shift PCR and DNA sequencing were then performed to characterize speci fic mtDNA deletions. A semiquantitative PCR method was used to determine th e proportion of the deleted mtDNA in detrusor. Finally, the mtDNA deletion and the urodynamic results were compared statistically. Results. A 4977-bp mtDNA deletion was identified in the human detrusor. Its incidence and proportion were found to increase after partial BOO (P = 0.0 05 and 0.012, respectively). The incidence of the mtDNA deletion was 4.2% ( 1 of 24) in the unobstructed group, 27.8% (5 of 18) in the equivocal group, and 40% (8 of 20) in the obstructed group. The mean proportion of the 4977 -bp deleted mtDNA was 23.7 and 12.7 times higher in the obstructed and equi vocal groups, respectively, compared with that of the unobstructed group. Conclusions. We found mtDNA with the 4977-bp deletion in human detrusor and an increase of this deletion after partial BOG. This molecular change migh t account for the previous observations of mitochondrial functional impairm ent and voiding dysfunction after partial BOG. UROLOGY 55: 603-607, 2000. ( C) 2000, Elsevier Science Inc.