Overexpression of aquaporin 1 in the tunica vaginalis may contribute to adult-onset primary hydrocele testis.

Mami Hattori,Toshimasa Uekusa,Ayako Suzue-Yanagisawa,Takumi Takeuchi,Masayoshi Zaitsu,Koji Mikami,Akiko Tonooka

doi:10.1155/2014/202434

Mami Hattori, Toshimasa Uekusa + Show 5 more

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https://doi.org/10.1155/2014/202434

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Abstract

To investigate the cause of the adult-onset primary noncommunicating hydrocele testis, protein expressions of water channel aquaporins (AQPs) 1 and 3 in the tunica vaginalis were assessed. Frozen tunica vaginalis specimens from patients with adult-onset primary hydrocele testis and control male nonhydrocele patients were subjected to Western blot analysis for the detection of AQP1 and AQP3 proteins. Paraffin-embedded sections of tunica vaginalis specimens were histochemically stained with anti-AQP1 and anti-AQP3 antibodies as well as an anti-podoplanin antibody to stain lymphatic endothelia. Hydrocele fluid was subjected to biochemical analysis. AQP1 protein expression in the tunica vaginalis was significantly higher in patients with adult-onset hydrocele testis than in the controls. The AQP3 protein was not detected in the tunica vaginalis. Histochemically, AQP1 expression in the tunica vaginalis was localized in vascular endothelial and smooth muscle cells. The densities of AQP1-expressing capillaries and lymphatic vessels were similar between the tunica vaginalis of the controls and those of hydrocele patients. Sodium levels were higher in the hydrocele fluid than in the serum. In conclusion, overexpression of the AQP1 protein in individual capillary endothelial cells of the tunica vaginalis may contribute to the development of adult-onset primary noncommunicating hydrocele testis as another aquaporin-related disease.

Highlights

Hydrocele testis is an accumulation of clear fluid between the tunica vaginalis and testis
The tunica vaginalis in the scrotum is composed of mesothelial cells and submesothelial interstitial tissue, similar to the peritoneum
Peritoneal dialysis is one of the renal replacement therapies for patients with end-stage renal disease and uses the peritoneum in the abdomen as a dialysis membrane, across which fluids and dissolved substances are exchanged between the blood and dialysate

Summary

Introduction

Hydrocele testis is an accumulation of clear fluid between the tunica vaginalis and testis. Adult-onset primary noncommunicating hydrocele testis causes progressive swelling and local discomfort on the affected side of the scrotum, and this has been attributed to the enhanced secretion and defective absorption of fluid in the space between the tunica vaginalis and testis. The tunica vaginalis in the scrotum is composed of mesothelial cells and submesothelial interstitial tissue, similar to the peritoneum. The threepore model of peritoneal transport describes the capillary membrane as a primary barrier that determines the amount of water and solutes transported to the interstitium and peritoneal cavity, mediated by pores of three different sizes [1]. The transport of water and solutes across the capillary, through interstitial tissue, and across the mesothelium was mathematically analyzed in a model [2]. A new version of the model considers the blood flow rate in capillaries and lymphatic absorption from tissue [3]

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