Alcohol-induced testicular atrophy. An experimental model for hypogonadism occurring in chronic alcoholic men.
Van Thiel D H,Gavaler J S,Lester R,Goodman M D
Gastroenterology
Elucidation of mechanisms involved in the hypogonadism and feminization observed in chronic alcoholic men requires the development of an experimental animals model system. Such an animal system should be inducible with ethanol feeding and should duplicate endocrine changes known to occur in chronic alcoholic men. We report such an animal model system. Animals fed a diet with ethanol accounting for 36% of total calories develop significant testicular, prostatic, and seminal vesicle atrophy (P less than 0.01) and greatly reduced plasma testosterone levels (P less than 0.01). Animals fed a similar diet with sucrose isocalorically substituted for ethanol do not. Testicular, prostatic, and seminal vesicular mass relative to body mass and plasma testosterone levels in these isocaloric control animals do not vary significantly from those obtained for age-matched control animals fed an ad libitum rat chow diet. These findings indicate that the caloric deprivation associated with chronic ethanol ingestion is not responsible for gonadal injury and atrophy of the sex steroid-sensitive tissues in the alcohol-fed animals. This animal model provides a useful means of directly examining perturbation in gonadal function that occurs in man as a consequence of chronic ethanol ingestion and confirms our previous data which suggest that ethanol is a primary testicular toxin.
Chronic alcohol administration causes expression of calprotectin and RAGE altering the distribution of zinc ions in mouse testis.
Giannessi Francesco,Scavuzzo Maria C,Giambelluca Maria A,Fornai Francesco,Morelli Girolamo,Ruffoli Riccardo
Systems biology in reproductive medicine
Several studies reported that chronic alcohol consumption alters the intestinal mucosa barrier, and subsequent entrance of endotoxins into the bloodstream. In many tissues endotoxin exposure causes the expression of calprotectin (CP) and the receptor for advanced glycation -end products (RAGE). In this study we investigated whether chronic alcohol administration causes expression of CP and RAGE in mouse testis. The distribution of free and loosely bound Zn(2+) (FLB-Zn(2+)) in the testicular tissues was also evaluated. Alcohol-induced testicular damage was documented by measuring testosterone blood levels and by light and electron microscope studies. Twenty mice were treated daily for three weeks with 3.0 g/kg of a 25% solution of alcohol. Ten mice were treated in the same period of time with a solution of maltose dextrins, isocaloric to alcohol. Twenty untreated mice were used as controls. Alcohol treated mice showed diffuse expression of CP and RAGE in the interstitial cells. RAGE was found also in the basal compartment of the seminiferous tubules. Depletion of FLB-Zn(2+) was observed in the adluminal compartment of the seminiferous tubules. Expression of CP and RAGE was not found in control mice and maltose dextrin treated mice. Our results indicated novel mechanisms by which alcohol acts in testis. Indeed, CP and RAGE may cause the generation of oxidants and inflammatory mediators, with negative impact on testicular functions. Depletion of FLB-Zn(2+) may contribute to the dysregulation of spermatogenesis.
10.3109/19396368.2014.949905
The blood vascular architecture of the rat testis: a scanning electron microscopic study of corrosion casts followed by light microscopy of tissue sections.
Murakami T,Uno Y,Ohtsuka A,Taguchi T
Archives of histology and cytology
The blood vascular bed of the rat testis was studied by scanning electron microscopy (SEM) of corrosion casts and by light microscopy of tissue sections. The testicular artery penetrates the pampiniform plexus and gives rise to the intertubular arterioles. Each of these arterioles courses in the intertubular connective tissue column, and gives off intertubular and peritubular capillaries. The intertubular capillaries pass the intertubular connective tissue column, whereas the peritubular capillaries reach the peritubular connective tissue sheet. The intertubular and peritubular capillaries anastomose with each other and converge into the intertubular venules in the intertubular connective tissue columns. Thus, the blood vascular bed of the rat testis consists of hexago- or pentago-columnar capillary networks which commonly surround the seminiferous tubules. The Leidig's cells are preferentially observed in the intertubular connective tissue columns. One of the intertubular capillaries is consistently thick, and directly continues into the intertubular venules (arteriolo-venular capillary channels), which finally drain into the pampiniform plexus. These findings suggest that the male sex hormone, testosterone, as secreted by the Leidig's cells, is discharged into the intertubular capillaries and then mainly carried by the arteriolo-venular capillary channels and intertubular venules into the pampiniform plexus. This specialized drainage may ensure the presence of highly concentrated testosterone in the pampiniform plexus and allow the testosterone-exchange from the pamipiniform plexus to the testicular artery. The arteriolo-venular capillary channels may also eliminate blood congestion in the testis to enhance the efficiency of the heat-exchange mechanism between the testicular artery and pampiniform plexus. Many arterio-arterial and arterio-venous anastomoses occur, which may regulate the blood flow within the testis.
10.1679/aohc.52.151
Acute spermatic cord torsion alters the microcirculation of the contralateral testis.
Kolettis P N,Stowe N T,Inman S R,Thomas A J
The Journal of urology
PURPOSE:The purpose of this study was to characterize the hemodynamic changes in the contralateral testis during acute spermatic cord torsion in anesthetized rats. MATERIALS AND METHODS:We used videomicroscopy to examine the microcirculation of the contralateral testis following acute torsion. Specifically, we examined the effect on vasomotion, a rhythmic dilation and constriction of the arterioles that is involved in fluid and nutrient exchange and modulation of local vascular resistance. In a separate set of experiments, blood flow in the contralateral internal spermatic artery was measured with an ultrasonic flow probe during acute torsion. RESULTS:Following 720 degrees torsion, the amplitude of vasomotion in the contralateral testis increased 121% (29.0 +/- 3.9% versus 13.0 +/- 1.7%) compared with controls. Blood flow in the contralateral internal spermatic artery decreased 43% after 2 hours' torsion. CONCLUSIONS:Acute spermatic cord torsion altered the microcirculation by increasing the amplitude of vasomotion and decreased total blood flow to the opposite testis. Because the hydraulic resistance of a blood vessel exhibiting vasomotion is always less than a vessel with the same average but static diameter, the observed microcirculatory changes may be an adaptive response to preserve local flow in the presence of decreased total flow. The long-term consequences of these changes in the microcirculation may affect testicular function and ultimately fertility.
Microvasculature of the human testis in correlation to Leydig cells and seminiferous tubules.
Ergün S,Stingl J,Holstein A F
Andrologia
The microvasculature of the human testis is closely related to the Leydig cells and the seminiferous tubules. Semi-thin sections of testicular tissue serve as a basis for the computer-aided 3-D reconstruction of the microvasculature, the seminiferous tubules and the Leydig cells. After vascular perfusion with glutaraldehyde (5.5%) and paraformaldehyde (4%), it is possible by means of light and electron microscopy, to analyse the organization of the capillaries between the Leydig cells (inter-Leydig cell capillaries) as well as of those within the lamina propria (intramural capillaries). These arise from arterioles, deriving from branches of the segmental arteries. The capillaries ramify between the Leydig cells and run either semi-circumferentially around the seminiferous tubules (peritubular capillaries) or penetrate the lamina propria of the neighbouring tubules. This is the beginning of the intramural capillary which after leaving the tubular wall continues to a further capillary path. Consequently, the microvasculature of the human testis with regard to the seminiferous tubules is subdivided into afferent, intramural and efferent capillaries. Leydig cell clusters are present on both the arterial and the venous sides of the microvasculature.
Age-associated changes in microvasculature of human adult testis.
Takizawa T,Hatakeyama S
Acta pathologica japonica
Age-associated architectural changes of the human testicular microvasculature from 70 autopsy cases were stereoscopically examined with a silicone-rubber injection technique. In the testis of a young subject, the interlobular main arteries run straight. The coiling phenomena of the interlobular centripetal or centrifugal arteries, which are commonly seen in adult testis, have been so far considered as physiological transformation of the vasculature. It was confirmed that the coiling changes in the interlobular main arteries of the human testis appear as an age-dependent alteration of the vasculature closely related to the volume of the gland. The practical importance of the spirallin or coiling of arteries is that it results in a considerable reduction of blood flow. The age-related coiling of the interlobular arteries is virtually accompanied by varying degrees of collapse of the peritubular capillary networks. The reduction of blood supply to the seminiferous tubules plays an active role in promoting aging of the testis. These stereoscopical observations of age-related transfiguration of testicular microvasculature were ascertained also by histometrical examinations.
Barrier properties of testis microvessels.
Holash J A,Harik S I,Perry G,Stewart P A
Proceedings of the National Academy of Sciences of the United States of America
The blood-testis barrier is believed to be constituted by tight junctions between Sertoli cells in seminiferous tubules and possibly by myoid cells that encircle these tubules. We now show that testis microvessels are endowed with several markers of barrier properties of brain microvessels, such as the glucose transporter, P-glycoprotein, and gamma-glutamyl transpeptidase. Quantitative EM studies show that the endothelium in testis, as in brain, is continuous and has long junctional profiles and few vesicles. However, a small proportion of testis capillaries have expansions in their junctional clefts suggestive of patent paracellular channels, which may explain their higher permeability. Because barrier features are thought to be induced and/or maintained in brain microvessels by astrocytes, we assessed whether astrocyte-like cells exist in the testis. We found that the intertubular Leydig cells, adjacent to microvessels, express the astrocyte markers: glial fibrillary acidic protein, glutamine synthetase, and S-100 protein. We suggest that the testis endothelium contributes to the blood-testis barrier and that these endothelial barrier features are influenced by Leydig cells. We believe that the endothelial and the epithelial (Sertoli) components of the blood-testis barrier are "in series" and complement each other in achieving a stable milieu for spermatogenesis.
10.1073/pnas.90.23.11069