Detrusor glycogen reflects the functional history of bladders with partial outlet obstruction

OBJECTIVE To assess the relationship between glycogen content in bladder detrusor tissue and historical bladder function in a guinea‐pig model of partial bladder outlet obstruction (PBOO). MATERIALS AND METHODS In male immature guinea pigs PBOO was created with a silver ring around the proximal urethra; a control group had a sham operation for comparison. Longitudinal individual urodynamic data were obtained weekly, so that guinea pigs were killed at different levels of bladder dysfunction. Bladder sections were stained with periodic acid‐Schiff (PAS) to assess overall morphology and glycogen granule density, scored from 0 (no glycogen) to 3. Glycogen scores were related to both the end‐stage and historical extremes of bladder function values. RESULTS Glycogen granules were seen only in the detrusor; as their number increased their location expanded from only close to the serosa (glycogen score 1), through the detrusor (score 2) up to the urothelium (score 3). A glycogen score of 0 correlated with normal values for all urodynamic variables. Compared with a glycogen score of 0 a score of 1 correlated with significant (P