Korean J Urol.  1999 Apr;40(4):464-470.

Ultrastructural Changes of Detrusor Muscle by Partial Obstruction of the Bladder Outlet in the Rat

• Son H
• Lee A
• Kim KM
• Choi H

Abstract

PURPOSE: Previous infravesical outflow obstruction study of rat bladder has demonstrated the increased expression of collagen genes after partial obstruction. But there are few reports about the electromicroscopic findings of rat urinary bladder after partial outlet obstruction. This investigation was carried out to study the ultrastructural changes in smooth muscle cells and collagen fibers after partial obstruction of rat bladder.
MATERIALS AND METHODS
Infravesical outflow obstruction was induced in Sprague-Dawley female rats. After 1, 2 and 4 weeks, the hypertrophied bladders were removed, fixated, embedded for electron microscopy and examined the ultrastructure of the bladder musculature.
RESULTS
Clumping of nuclear chromatin, dilated sarcoplasmic reticulum and mitochondrias, depletion of ribosomes, disarrangement of the myofilaments and dense bodies, collagen deposition, and thickening and multiplying of basal lamina were observed.
CONCLUSIONS
These results demonstrate that partial bladder outlet obstruction in the rat results in numerous changes of the organelles of smooth muscle cells and collagen deposition in the detrusor, which will be able to explain the resultant alteration in detrusor contractility and compliance.

Keyword

Urinary bladder; Obstruction; Electron microscope; Smooth muscle; Collagen

MeSH Terms

Animals
Basement Membrane
Chromatin
Collagen
Compliance
Female
Humans
Microscopy, Electron
Mitochondria
Muscle, Smooth
Myocytes, Smooth Muscle
Myofibrils
Organelles
Rats*
Rats, Sprague-Dawley
Ribosomes
Sarcoplasmic Reticulum
Urinary Bladder Neck Obstruction
Urinary Bladder*
Chromatin
Collagen