Testicular vascular permeability: effects of experimental lesions associated with impaired testis function

Establishment of a rabbit model of different degrees of testicular torsion

INTRODUCTION AND OBJECTIVES

Different degrees of testicular torsion result in varying degrees of testicular damage, which influences treatment options and outcomes. Therefore, establishing a testicular torsion model with different degrees is necessary for clinical diagnosis.

MATERIALS AND METHODS

Rabbits were randomly divided into four groups and their spermatic cords were twisted at 0 °, 180 °, 360 °, and 720 °, respectively. Color Doppler flow imaging (CDFI) were performed to evaluate the blood supply in testicles. The twisted testicles were surgically removed at six hours post-operation and were evaluated by morphological observation and Hematoxylin and Eosin staining.

RESULTS

CDFI signals were gradually decreased as the degree of testicular torsion increased, and scores of CDFI in the 360 ° and 720 ° groups were significantly decreased at postoperative six hours compared to pre-surgery. Compared to the sham, the testicle in the 180 ° group exhibited slight congestion, whereas the testicles in the 360 ° and 720 ° groups were dark red in color and had severe congestion and unrecognizable vessels. Hematoxylin and Eosin staining showed mild spermatogenic cell reduction and testicular interstitial hemorrhage in the 180 ° group. In the 360 ° and 720 ° groups, disordered seminiferous tubules, shed spermatogenic cells in tubules, inflammatory cell infiltration, and severe hemorrhage were found. In comparison with the sham, interstitial hemorrhage scores in the 360 ° and 720 ° groups were significantly higher, and scores of germinal epithelial cell thickness in the three testicular torsion groups were significantly decreased.

CONCLUSIONS

Collectively, we successfully constructed a testicular torsion model with different degrees in rabbits.

The ameliorative effects of Ginkgo biloba on apoptosis, LH-R expression and sperm morphology anomaly in testicular torsion and detorsion

Torsion/detorsion (T/D) induces testicular damages in both germinal epithelial and interstitial tissues. Ginkgo biloba extract (GbE) exerts antioxidant and free radical scavenger. We investigated the effect of GbE on testicular tissues, Leydig and sperm cells in rats injured with T/D. Twenty-eight Wistar albino rats were randomly assigned into four groups (Control, GbE, Treatment: T/D+GbE, T/D). T/D performed to the rats in torsion, treatment received GbE (50 mg/kg) 1 hr before T/D, GbE group received only GbE (50 mg/kg) and control was defined as sham group. After T/D, the testes along with epididymis were removed and processed. LH-R expression, apoptosis, sperm morphology and histopathological damage scores were determined for each group. Testicular T/D caused significant increases in apoptosis and sperm morphology anomaly, and a significant decrease in Johnsen's testicular biopsy scores, LH-R expression of Leydig cell and normal sperm cell count. GbE ameliorated testicular histopathology and caused significant increases in LH-R expression, normal sperm cell count in the treated and particularly GbE group. Consequently, GbE may prevent testicular injury and enhance Leydig and sperm cell activity following both T/D and normal situation owing to its antioxidant, anti-apoptotic, free radical scavenger and anti-inflammatory effects.

The role of varicocele treatment in the management of non-obstructive azoospermia

The literature on male reproductive medicine is continually expanding, especially regarding the diagnosis and treatment of infertility due to non-obstructive azoospermia. The advent of in vitro fertilization with intracytoplasmic sperm injection has dramatically improved the treatment of male infertility due to nonobstructive azoospermia. Assisted reproduction using testicular spermatozoa has become a treatment of hope for men previously thought to be incapable of fathering a child due to testicular failure. In addition, numerous studies on non-obstructive azoospermia have reported that varicocelectomy not only can induce spermatogenesis but can also increase the sperm retrieval rate; however, the value of varicocelectomy in patients with non-obstructive azoospermia still remains controversial. The purpose of this review is to present an overview of the current status of varicocele repair in men with non-obstructive azoospermia.

The great debate: varicocele treatment and impact on fertility

OBJECTIVE

To evaluate the current literature on the impact and potential mechanisms of varicocele repair on male fertility.

DESIGN

Pertinent articles were identified through computer PubMed search on varicocele repair and male factor infertility. References of selected articles were hand searched for additional citations.

CONCLUSION(S)

Varicocele repair has been shown to reverse a spectrum of effects contributing to men with impaired fertility. Clinical studies on the intervention have illustrated variable effects on postoperative sperm parameters and pregnancy rates (PR). Studies with conflicting results suffer from a significant number of confounding variables such as variable repair technique or lack of controls. Additional studies are warranted on the role of modern microsurgical varicocelectomy given the improvements in assisted reproductive technologies (ART).

In vivo detection of apoptotic cells in the testis using fluorescence labeled annexin V in a mouse model of testicular torsion

PURPOSE

It is well established that experimental testicular torsion induces germ cell specific apoptosis. Annexin V (BD Pharmingentrade mark) binds phosphatidylserine that becomes exposed on the cell membrane in apoptotic cells. In vivo detection of apoptotic cells with fluorescently labeled annexin V is an emerging technique that we evaluated for detecting apoptotic germ cells in a mouse model of testicular torsion.

MATERIALS AND METHODS

Annexin V labeled with an indocyanine fluorophore (bisfunctional succinimidyl ester of cyanine 5.5) (Amersham, Little Chalfont, United Kingdom) was injected intravenously in mice 18 hours after the repair of unilateral 720-degree testicular torsion for 2 hours. Serial fluorescence images were obtained 21, 24, 28 and 42 hours after torsion repair. Relative fluorophore localization was visualized in vivo using an optical small animal imaging system mounted with a filter in near infrared light. Average fluorescence intensity in torsed and sham testes was quantified in images of testes in situ exposed through an abdominal incision and in ex vivo testes.

RESULTS

A significant increase in fluorescence intensity was found in images of torsed vs sham operated testes. This was seen in ex vivo, exposed and in vivo testes (215%, 250% and 161%, respectively, p <0.05). Bisfunctional succinimidyl ester of cyanine 5.5 conjugated to dehydrogenase, a protein with a size similar to that of annexin V, was used to assess for capillary leakage. It was also more localized to the torsed testis relative to its contralateral sham control whether exposed or ex vivo (174% and 176%, respectively).

CONCLUSIONS

To our knowledge this study demonstrates for the first time the possibility of in vivo near infrared fluorescence imaging of apoptotic germ cells after testicular torsion in mice. It shows important confounding factors that must be considered as this new imaging technique is developed for detecting apoptotic cells in vivo in testes or in any other organ.

Effects of gabexate mesilate on ischemia-reperfusion-induced testicular injury in rats

The aim of this study was to determine the effects of a synthetic serine protease inhibitor, gabexate mesilate (GM), in rats with ischemia-reperfusion (I-R) damage due to unilateral testicular torsion. Thirty male Sprague-Dawley rats were separated into three groups, each containing ten rats. A sham operation was performed in group 1 (control). In group 2 (I-R/untreated), 1 h detorsion of the testis was performed after 6 h of unilateral testicular torsion. In group 3 (I-R/GM), after performing the same surgical procedures as in group II, gabexate mesilate was given intravenously. In all experimental rats, ipsilateral orchiectomies were performed for histological examination and measuring the tissue levels of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px). MDA values and the testicular injury score decreased and SOD, CAT and GSH-Px values increased in the GM-treated group compared to the I-R/untreated group. The Tc-99m pertechnetate uptake ratio and the perfusion index were significantly decreased in the group 2 compared to the group 1 and 3 rats. In group 3, these values were significantly increased compared to group 2. Most of the specimens in the GM-treated group showed grade-I testicular injury. However, the injuries in the I-R/untreated rats varied between grade-III and grade-IV. The results of this study show that GM may play a role in reducing the injury caused by I-R.

Spermatic cord torsion, reactive oxygen and nitrogen species and ischemia–reperfusion injury

Mammalian testes are highly sensitive to oxidative free radical damage. Acute scrotum is a clinical syndrome mainly caused by torsion of the spermatic cord that constitutes a surgical emergence affecting newborns, children and adolescents. This syndrome often leads to infertility of the ipsilateral (torted) and contralateral (not torted) testis, an outcome that makes surgical intervention mandatory. There is a controversy involving the effects of ischemia and reperfusion on ipsilateral and contralateral testes after unilateral torsion and detorsion of the spermatic cord. Conflicting reports have led to two distinct and opposite recommendations regarding surgical intervention: detortion and preservation of the ipsilateral testis, or ipsilateral orchiectomy to preserve contralateral fertility. Early detortion surgery in humans preserves fertility, but after prolonged torsion periods followed by preservation of the ipsilateral fertility of both testis is jeopardized. Lowered contralateral blood flow after unilateral testicular torsion is associated with reactive oxygen species (ROS) overgeneration and therefore with the corresponding tissue damage. Reperfusion time appears to be determinant of contralateral testes damage due to the consequent oxidative insult that accompanies the rise in ROS following ischemia-reperfusion. Nevertheless, more investigations on the molecular mechanisms and the antioxidant status in testis are necessary to ascertain the contribution of ROS to the tissue damage produced by spermatic cord torsion in experimental animals and humans.

The changes in testicular vascular permeability during progression of the experimental varicocele

OBJECTIVES

The vascular permeability of testicular capillaries which play a role in controlling the formation of testicular interstitial fluid was studied during the progressive course of experimental varicocele.

MATERIALS AND METHODS

The pathology was developed through partial ligation of left renal vein in four groups of rats. Controls of each group were subjected to sham surgery. After different periods of varicocele creation (1, 3, 6 and 14 weeks), animals' testes per one of the study groups were extirpated and weighed. The volume density percentages of polymorphnuclear leukocytes (PMN) per testicular blood vessels; which are markers of the increase in vascular permeability, were also estimated in both testes. To further verify the obtained findings, another group of animals received human chorionic gonadotrophin (hCG) treatment 6 weeks after varicocele creation and their histopathological sections were examined.

RESULTS

Animal testes' of (1 and 3 weeks) groups were found to be significantly heavier (p<0.05) than their controls. PMN showed accumulation in testicular blood vessels and their volume density percentages per these blood vessels in both testes were significantly higher in each study group than in those of its controls. However, these percentages showed gradual significant decline as the duration of varicocele bearing gradually increased. The hCG-treated animals revealed more accumulation of the PMN in their histopathological sections.

CONCLUSION

The present results suggest that experimental varicocele may induce an increase in testicular vascular permeability, which then decreases gradually with time. It is supposed that parallel changes in the rate of formation of testicular interstitial fluid may be accompanied. The results have also showed that the vasculature of the testis with experimental varicocele can still respond to hCG.

Microvascular testicular blood flow as evaluated by laser Doppler flowmetry after the surgical induction of varicocele

This study was conducted to evaluate the changes in microvascular testicular blood flow (microvascular TBF), which may be associated with varicocele. The pathology was developed through partial ligation of left renal vein in 4 groups of rats. Controls of each group underwent sham surgery. It was observed that microvascular TBF dropped and its vasomotion became inhibited once the left renal vein was partially ligated as studied by laser Doppler flowmetry (LDF). Four to five minutes later, blood flow rose to the pretreatment level and that of controls. Vasomotion reappeared with a uniform frequency and amplitude. At different periods of varicocele bearing (1, 3, 6, and 14 weeks) microvascular TBF was reevaluated. Vasomotion appeared intact without any abnormalities in the 4 groups. To examine the response of testicular microvasculature after surgical creation of the varicocele to pharmacological stimulation another group of animals received human chorionic gonadotropin (hCG) treatment 6 weeks after varicocele creation. Vasomotion was inhibited in these animals. In conclusion, LDF is a suitable tool to evaluate microvascular TBF in vivo. It can detect acute changes in blood flow that may happen at surgical induction of varicocele. In addition, the vasculature of the testis with a surgically induced varicocele can still respond to hCG stimulation.