Morphogenesis of the ureterovesical junction:a histologic and microanatomic study in the rat
| Autor: | Judith Hohlfeld, Gezim Dushi, Nicolas Lutz, Peter Frey |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Amniotic fluid
Urology Urinary system Urinary Bladder Gestational Age Vesicoureteral reflux Mesonephric duct chemistry.chemical_compound Embryonic and Fetal Development Ureter medicine Morphogenesis Animals Urea Vesico-Ureteral Reflux Creatinine Fetus business.industry Muscle Smooth Anatomy medicine.disease Amniotic Fluid Rats medicine.anatomical_structure chemistry Animals Newborn Ureterovesical Junction Models Animal Microscopy Electron Scanning business |
| Zdroj: | Urology. 60(4) |
| ISSN: | 1527-9995 |
| Popis: | Objectives To investigate the development of the ureterovesical junction in rats. Methods A total of 110 albino rats (50 prenatal and 60 newborn) with a gestation of 21 days were studied at the age of 17 days after conception until 5 days after birth. The lower urinary tract was microdissected. Microphotography (110 animals), histologic examination (44 animals), and scanning electron microscopy (66 animals) of the ureterovesical junction were performed. Urea and creatinine from the amniotic fluid of 20 fetuses and from the urine of 10 neonates were measured. Results At day 17 after conception, separate penetration of the mesonephric duct and ureter into the wall of the urogenital sinus was observed. Continuity between the lumen of the ureter and the urogenital sinus was established on day 19 after conception. The straight passage of the intramural ureter into the urogenital sinus at day 17 after conception changed to the definitive L -shape with a vertical entry into the bladder on day 5 after birth. In the distal ureter, the change of the mesenchymal tissue into immature smooth muscle was first observed at birth, and the muscle became mature on the fifth postnatal day. At birth, Waldeyer’s sheath was recognized. The creatinine and urea levels were stable prenatally (average 22.4 μmol/L and 6.88 mmol/L, respectively) and rose significantly postnatally (average 133 μmol/L and 32.65 mmol/L, respectively). Conclusions The attachment of the ureter to the urogenital sinus and later to the bladder, the modification of its passage, and its mobility within Waldeyer’s sheath may be essential in preventing vesicoureteral reflux. The production of urine and its flow does not seem to be the trigger of ureteral smooth muscle formation. |
| Databáze: | OpenAIRE |
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