The protective arm of the renin -angiotensin system may counteract the intense inflammatory process in fetuses with posterior urethral valves / O braço protetor do sistema renina-angiotensina pode contrapor-se ao intenso processo inflamatório em fetos com válvula de uretra posterior

Abstract Objective: Posterior urethral valve is the most common lower urinary tract obstruction in male children. A high percentage of patients with posterior urethral valve evolve to end‐stage renal disease. Previous studies showed that cytokines, chemokines, and components of the renin-angiotensin system contribute to the renal damage in obstructive uropathies. The authors recently found that urine samples from fetuses with posterior urethral valve have increased levels of inflammatory molecules. The aim of this study was to measure renin-angiotensin system molecules and to investigate their correlation with previously detected inflammatory markers in the same urine samples of fetuses with posterior urethral valve. Methods: Urine samples from 24 fetuses with posterior urethral valve were collected and compared to those from 22 healthy male newborns at the same gestational age (controls). Renin-angiotensin system components levels were measured by enzyme‐linked immunosorbent assay. Results: Fetuses with posterior urethral valve presented increased urinary levels of angiotensin (Ang) I, Ang‐(1‐7) and angiotensin‐converting enzyme 2 in comparison with controls. ACE levels were significantly reduced and Ang II levels were similar in fetuses with posterior urethral valve in comparison with controls. Conclusions: Increased urinary levels of angiotensin‐converting enzyme 2 and of Ang‐(1‐7) in fetuses with posterior urethral valve could represent a regulatory response to the intense inflammatory process triggered by posterior urethral valve.

Resumo Objetivo: A válvula de uretra posterior é a obstrução do trato urinário inferior mais comum em crianças do sexo masculino. Uma alta porcentagem de pacientes com válvula de uretra posterior evolui para doença renal em estágio final. Estudos anteriores mostraram que citocinas, quimiocinas e componentes do sistema renina-angiotensina contribuem para o dano renal em uropatias obstrutivas. Recentemente, descobrimos que amostras de urina de fetos com válvula de uretra posterior tinham níveis aumentados de moléculas inflamatórias. O objetivo deste estudo foi medir as moléculas de renina-angiotensina e investigar sua correlação com marcadores inflamatórios previamente detectados nas mesmas amostras de urina de fetos com válvula de uretra posterior. Métodos: Amostras de urina de 24 fetos com válvula de uretra posterior foram coletadas e comparadas com amostras de urina de 22 recém-nascidos saudáveis de mesma idade gestacional (controles). Os níveis dos componentes de SRA foram medidos por ensaio de imunoabsorção enzimática. Resultados: Os fetos com válvula de uretra posterior apresentaram níveis urinários aumentados de angiotensina (Ang) I, Ang-(1-7) e enzima conversora de angiotensina 2 em comparação com os controles. Os níveis de enzima conversora de angiotensina eram significativamente menores e os níveis de Ang II eram semelhantes nos fetos com válvula de uretra posterior em comparação com os controles. Conclusões: O aumento dos níveis urinários de enzima conversora de angiotensina 2 e de Ang-(1-7) em fetos com válvula de uretra posterior poderia representar uma resposta regulatória ao intenso processo inflamatório desencadeado pela válvula de uretra posterior.

Prenatal development of pelvic urethra in goat (Capra hircus) / Desarrollo prenatal de la uretra pélvica en cabras (Capra hircus)

The study was conducted on the embryo/foeti of goat from 0-150 days of gestation, divided into group I (0-30 days), group II (31-60 days), group III (61-90 days), group IV (91-120 days) and group V (121-150 days of gestation). In group I whole embryo was processed and serial sections were cut whereas, in rest of the groups, pelvic urethra was dissected out and the tissues from the representative areas were used for the study. Grossly, on 49.33 days of gestation the pelvic urethra was present in the form of smooth cylindrical tube, approximately 4mm in length. The primordial of vesicular gland and bulbourethral gland appeared on 52 days of gestation at the junction of neck of urinary bladder with pelvic urethra and at the junction of pelvic and penile urethra respectively. The length, width, height and circumference of pelvic urethra increased with increased in gestation period, however the length (7 times) and circumference (9 times) increased maximum from group II to group V. The morphometrical parameters (length, width, height and circumference) of pelvic urethra were significantly correlated with the age and weight of foetus throughout gestation period. The colliculus seminalis, which was present in the form of ridge on 72 days of gestation, became distinct on 75 days of gestation. Histologically, on 28 days of gestation, the urogenital sinus was present as a cleft with in the cluster of cells. On 55 days of gestation, the process of luminization started with in the wall of pelvic urethra, which started first in its caudal part and proceeded cranially. All the four layers (Tunica mucosa, submucosa, muscularis and adventitia) were distinct. The lumen was lined with 3-4 layers of stratified epitheliumin group II but in group III on 70 days of gestation and beyond this distinct transitional epithelium was present. The formation of cavernous spaces started at 59 days of gestation...

El estudio se realizó sobre embriones/fetos de cabras de 0 a 150 días de gestación, divididos en grupo I (0-30 días), grupo II (31-60 días), el grupo III (61-90 días), grupo IV (91 a 120 días) y grupo V (121-150 días de gestación). En el grupo I embriones enteros fueron procesados mediante cortes seriados, en el resto de los grupos, la uretra pélvica fue disecada y los tejidos de las áreas representativas se utilizaron para su estudio. Macroscópicamente, a los 49,33 días de gestación de la uretra pélvica estaba presente en forma de tubo cilíndrico liso, aproximadamente 4 mm de longitud. El primordio de la glándula vesicular y la glándula bulbouretral apareció a los 52 días de gestación en el cruce de cuello de la vejiga urinaria con la uretra pélvica y el cruce de la uretra pélvica y pene respectivamente. La longitud, ancho, alto y circunferencia de la uretra pélvica aumentó con el avance del período de gestación, sin embargo, la longitud (7 veces) y el perímetro (9 veces) aumentó en el grupo II y V. Los parámetros morfométricos (longitud, ancho, alto y circunferencia) de la uretra pélvica se correlacionaron significativamente con la edad y el peso del feto durante toda la gestación. El colículo seminal, que estaba presente en la forma de cresta a los 72 días de gestación, se mostró distinta a los 75 días de gestación. Histológicamente, en 28 días de gestación, el seno urogenital estaba presente como una hendidura con un grupo de células. En 55 días de gestación, el proceso de luminización comenzó en la pared de la uretra pélvica, que comenzó en su primera parte caudal y procedió cranealmente. Las cuatro capas (túnica mucosa, submucosa, muscular y adventicia) eran distintas. La luz estaba cubierta con 3-4 capas de epitelio estratificado en el grupo II, pero en el grupo III a los 70 días de gestación y más, un epitelio de transición distinto estuvo presente. La formación de espacios cavernosos comenzó a los 59 días de gestación...

Disposition of the striated urethral sphincter and its relation to the prostate in human fetuses

OBJECTIVE: To describe the arrangement of the muscle fibers of the striated urethral sphincter and its relationship with the prostate during the fetal period in humans. MATERIALS AND METHODS: We analyzed 17 prostates from well preserved fresh human fetuses ranging in age from 10 to 31 weeks postconception (WPC). Transversal sections were obtained and stained with Gomori's trichrome and immunolabeled with anti alpha-actin antibody. RESULTS: We found that the urethral striated sphincter (rabdosphincter) is located on the periphery of the smooth muscle and there was no merge between striated and smooth muscle fibers in any fetal period. In the prostate apex, the striated sphincter shows a circular arrangement and covers completely the urethra externally, whereas adjacent to verumontanum, it looks like a "horseshoe" and covers only the anterior and lateral surfaces of the urethra. Near the bladder neck, in fetuses younger than 20 WPC, we have found striated muscle fibers only at the anterior surface of the prostate, while in fetuses older than 20 WPC, the striated muscle covers the anterior and lateral surfaces of the prostate. CONCLUSIONS: The urethral sphincter muscle covers the anterior and lateral surfaces of the urethra in all fetuses older than 20 WPC, close to the bladder neck and at the distal prostate. In the region of the prostate apex, the urethral sphincter covers completely the urethra circularly. The knowledge of the normal anatomy of the urethral sphincter in fetuses could be important to understand its alterations in congenital anomalies involving the base of the bladder, the bladder neck and the proximal urethra.