Fig. 1.

Comparison of urinary bladder size among ROMK^+/+, ROMK1^−/−, and ROMK^−/− male mice at ages of 3 and 12 mo (n = 4, each group). The longest length from the bladder neck to dorm was measured after full filling of saline in the urinary bladder. The longest length from bladder neck to dorm is ~0.8–1 cm in ROMK^+/+ mouse at both ages (A and D). The bladder length is more than 2 cm larger in 12-mo-old ROMK^−/− mouse (C and F). The length of the urinary bladder was also significantly increased in ROMK1^−/− mice over ROMK^+/+ mice (B and E).