The Experimental Study Of The Mechanisms Of Contralateral Testicular Impairment Induced By Unilateral Cryptorchid And The Prorective Effect On Testis In Rats

Crytorchidism is one of the common diseases in the genitourinary system,it has been shown to reduce the ability of male fertility. The subsequent infertility associated with cryptorchidism is attributed to testicular exposure to suprascrotal temperature which makes germinal epithelium cell (germ cell), Steroli cell and Leydig cell of testis degenerate. Recent work has been shown that the the contralateral descended testis pathological impairment in unilateral cryptorchidism. But the molecular mechanisms responsible have not been elucidated.The genitofemoral nerve (GFN) arises from the first and second lumbar vertebral plexus. Its fibers supply the gubernaculums, the cremaster muscle and th tunica vaginalis testis and it is main afferent fibers in testis. The testis and epididymis receive no somatic innervation. Their visceral supply is derived from nerve plexuses surrounding the arteries. Calcitonin gene-related peptide (CGRP) composed of 37 amino acids by alternative splicing of messenger RNA transcript of calcitoini gene. It is a neuropeptide with principal vasodilatation in body. In the testis a balance in production and scavenging of reactive free species (ROS) may be important for normal spermatogenesis. The ROS levels are kept in check by antioxidant enzymes, such as superoxide dismntase, glutathione peroxidase and catalase. Glutathione composed of glutamyl, cysteinyl and glycine and played a key role in many biological proceses, in eluding the synthesis of proteins and DNA and the transport of amino acids-but notably, it played a key role in protecting cells against damage by oxidants and electrophiles.The objectives of this study were to establish two animal models of cryptorchidism and the transected genitofenmoral nerve (GFN),to investigate the mechanism of contralateral testicular impairment induced by unilateral cryptorchid in molecular neurophysiology andgene expression and the protective effect of glutathione (GSH) in the bistralateral testes.Methods: 1. Sixty Immature male Sprague Dawley Rats (21-day-old) were divided into four groups, (1)the control group; (2)Namely cryptorchid; (3)the cryptorchid group following the division of the GFN; (4)the crytorchid group following being injected with GSH. The animals were killed by cervical dislocation at the 90days after surgery, the testes were removed, dacapsulated, the weighed. 2. The distribution of the CGRP immunoreactive nerve fibers in testes had been studied by means of immunohistochemisty technique. We adopted RT-PCR method to study the mRNA expression level of antioxidant related enzymes including glutathione peroxidase(GPX), copper/zine-superoxide dismutase (Cu/Zn-SOD)and catalase (CAT)in testes. The concentration of melodic diethyl aldenyde(MDA) and GSH in testicular tissues were evaluated by using spectrophotometric determination. Germ cell apoptosis were detected by terminal deoxynucleotidyl transferase mediated d-UTD nick end labeling method. The HE slices of testes were observed by light microscopy. The ultra-structure of Sertoli cells was observed under transmission electron microscopy.Results : 1.As compared to the control group, the distribution of CGRP immunoreactive nerve fibers and the concentration of CGRP and GSH and mRNA expression lever of GPX and Cu/Zn-SOD in the crytorchid group were decreased significantly, as well as the level of MDA and the number of apoptotic germ cells were increased significantly (P<0.01).In the cryptochidism testes, the density of seminiferous tubules decreased and germinal epithelium degenerated, there was scarcely spermatozoa in the tubules, and there was pathological changes in Sertoli cells, it is manifested as expansion of mitochondria and smooth endoplasmic reticulum. 2. After the GFN was divided, the concentration and distribution of CGRP in the contralateral testes in crytorchidism was increased significantly (P<0.01).The pathological impairment of germ cells and Sertoli cells were improved. 3. As compared to the cryptorchid group, in the cryptorchid groupfollowing being injected wit...