Voiding patterns in uroplakin II knockout mice

Abstract

Uroplakins are integral components of urothelial plaques crucial to normal genitourinary function. We examined the effect of uroplakin II (UPII) gene deletion on mouse voiding function and sought to develop a simple surrogate measurement of bladder function in mice using ultraviolet visualization of urinary voiding patterns. Wild type (WT; n=6) and UPII knockout (KO; n=6) mice were evaluated by cystometric analysis and voiding pattern markings. The voiding pattern markings were graded by independent observers on a 1–5 scale according to the degree of dispersion of the voided urine. These grades were then correlated to the cystometric results. The UPII KO mice demonstrated detrusor overactivity (DO) and increased urinary frequency. Furthermore, the voiding pattern markings were markedly more dispersed with increased severity of DO. Consistent with these findings, the Pearson correlation coefficients for the observed voiding patterns were highly correlated with bladder weight, basal pressure, threshold pressure, and intermicturition pressure measurements obtained during cystometry (p value < 0.05). In conclusion, UP II KO mice demonstrated DO and urinary frequency. The ultraviolet visualization of urinary voiding patterns of mice correlated well with certain measures of standard cystometric evaluations, and may provide a simple, possibly automated, noninvasive method of evaluating mouse DO.