# Time‐dependent bladder activity changes in streptozotocin‐induced female diabetic rats

## TL;DR

This study shows how diabetes affects bladder function in female rats over time, with changes in urination patterns and bladder strength.

## Contribution

The study identifies a turning point at 8 weeks after diabetes induction when bladder dysfunction shifts from overactive to underactive.

## Key findings

- Urination frequency increased in early diabetes stages (3 days), while voiding interval worsened at 8–12 weeks.
- Bladder contractile force was enhanced at 8 weeks, but voiding efficiency declined at 24 weeks.
- Histological analysis showed increased fibrosis at 4 weeks of diabetes.

## Abstract

This study aimed to investigate the long‐term physiological and morphological changes in the bladders of diabetic rats. Sixty‐nine female Sprague–Dawley rats were divided into a control and six diabetic (3 days and 2, 4, 8, 12, and 24 weeks after induction of type 1 diabetes) groups. Metabolic cages and cystometry were used to evaluate bladder function. Bladder contractility was assessed using an organ bath test, and Masson's trichrome staining was performed. In the metabolic cage study, the urination frequency during the dark period significantly increased in the early stages at 3 days of diabetes (p < 0.05). The voiding interval significantly increased (p < 0.05) at 8–12 weeks of diabetes, while the residual urine volume and voiding efficiency worsened at 24 weeks. In the organ bath study, the dose–response curve of carbachol for median effective concentration did not change; however, the bladder contractile force was enhanced at 8 weeks (p = 0.028). Histological analysis revealed increased fibrosis at 4 weeks of diabetes. Diabetic bladder dysfunction is characterized by storage and voiding bladder activity changes in the early stages that induces urinary frequency and reduced voiding efficiency in the late phase; this turning point occurs at 8 weeks after diabetes.

Diabetic bladder dysfunction is characterized by storage and voiding bladder activity changes in the early stages that induces overactive bladder and underactive bladder in the late phase; this turning point occurs at 8 weeks after diabetes.