A novel method of urinary sphincter deficiency: Serial histopathology evaluation in a rat model of urinary incontinence

In this study, we developed a novel technique of irreversible sphincter deficiency by pudendal nerve transection (PNT) using 40 female rats for studying the pathophysiology of stress urinary incontinence associated with childbirth.

Of the 40 rats, 10 served as controls and the remaining underwent bilateral PNT at the anastomotic lumbosacral trunk level. Urethral morphological changes following bilateral PNT were assessed with serial hematoxylin and eosin (H&E) and immunohistochemistry (IHC) staining methods at 50, 90, and 130 days post intervention. Leak point pressure (LPP) measurement was used to determine the effect of pudendal injury on urethral outlet resistance after the transection. H&E and IHC staining showed irreversible loss of striated muscle mass of the sphincter region and increase in collagen deposition compatible with muscle atrophy. LPP measurements also significantly decreased following bilateral PNT. In conclusion, a novel method of irreversible sphincter insufficiency was developed. This model effectively decreased urethral outlet resistance and caused irreversible striated muscle atrophy. We suggest that this technique can be used to develop a permanent sphincter deficiency model for the preclinical testing of treatment modalities exclusively triggering the pudendal nerve. This article is protected by copyright. All rights reserved.

Anatomical record (Hoboken, N. J. : 2007). 2015 Nov 17 [Epub ahead of print]

Reza Khorramirouz, Sarah Mozafarpour, Seyedeh Maryam Kameli, Sanam Ladi Seyedian, Nasim Oveisi, Zahra Rahimi, Maryam Alijani, Abdol-Mohammad Kajbafzadeh

Pediatric Urology Research Center, Section of Tissue Engineering and Stem Cells Therapy, Department of Urology, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran (IRI). , Pediatric Urology Research Center, Section of Tissue Engineering and Stem Cells Therapy, Department of Urology, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran (IRI). , Pediatric Urology Research Center, Section of Tissue Engineering and Stem Cells Therapy, Department of Urology, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran (IRI). , Pediatric Urology Research Center, Section of Tissue Engineering and Stem Cells Therapy, Department of Urology, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran (IRI). , Pediatric Urology Research Center, Section of Tissue Engineering and Stem Cells Therapy, Department of Urology, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran (IRI). , Pediatric Urology Research Center, Section of Tissue Engineering and Stem Cells Therapy, Department of Urology, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran (IRI). , Pediatric Urology Research Center, Section of Tissue Engineering and Stem Cells Therapy, Department of Urology, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran (IRI). , Pediatric Urology Research Center, Section of Tissue Engineering and Stem Cells Therapy, Department of Urology, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran (IRI).

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