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

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.