Angioarchitecture of the bovine spermatic cord

We described the topography and morphometry of the testicular artery, pampiniform plexus veins, and indirect connections between them in the spermatic cord of the bull. Sixty microcorrosive casts of bovine spermatic cords were analyzed macroscopically, by stereomicroscopy, and by scanning electron microscopy. The average size of the testicles was 94.6 × 49.7 × 54.7 mm. The testicular artery formed a superiorly pointed cone‐like structure with its base fixed to the proximal part of the gonad. The artery gave off one or two branches to the head of epididymis and to the deferens duct. The pampiniform plexus originated from intra‐tunical veins. Veins of the pampiniform plexus were of smaller diameter but larger number than intra‐tunical ones. The density of the veins of the pampiniform plexus was 9.37 ± 1.07 mm^?2. The testicular vein began 90–121 mm above the superior pole of the testis. In 2.9% of specimens, the testicular vein was doubled. Numerous anastomoses among veins of pampiniform plexus were observed. Additionally, indirect anastomoses between the testicular artery and pampiniform plexus veins formed by the capillary network of the vasa vasorum of the testicular artery were visualized by scanning electron microscopy. In all cases, narrowings in the casts of the precapillary vessel were observed. We also documented the vasa vasorum of the testicular artery in bulls. The density of these vessels was 22.87 ± 11.48 mm^?2. The indirect arteriovenous connections together with the presence of circular constrictions of the lumen in precapillary vessels may play a role in testicular blood flow regulation. J. Morphol., 2011. © 2011 Wiley‐Liss, Inc.     

Changes in testis blood flow,the spermatic artery and prostaglandin F 2α content in testis tissue of heat-stressed rams

Blood flow to the testis, measured by the¹³³-Xenon isotope clearance technique, initially increased after rams were exposed to elevated (32°C) temperature. However, after 5 and 7 days continuous exposure, blood flow decreased significantly. Similar changes in blood flow to the testis were found during whole body exposure to elevated temperature, or when the temperature of the testis was increased by scrotal heating. After one week of heating the wall of the spermatic artery in the middle region of the pampiniform plexus had thickened, and the arterial lumen had decreased significantly. The PGF ₂ content in the testis of rams exposed to elevated temperature increased significantly. It is tentatively postulated that the higher levels of PGF ₂ in the testis of rams exposed to elevated temperature may be responsible for impaired spermatogenic function by constricting the spermatic artery in the pampiniform plexus region and thereby reducing blood flow to the testis.Published with approval of the Director of Kentucky Agricultural Experiment Station as Journal Article 75-5-150.Presented at the Seventh International Biometeorological Congres, 17–23 August 1975. College Park, Maryland, U.S.A.     

The influence of the sampling point on testicular steroid concentrations in spermatic venous blood: a physiological approach to evaluate testicular secretion

In the present study, we have evaluated the influence of the location of the blood sampling in the spermatic vein on the steroid concentrations observed. Simultaneous blood sampling at two different points of the spermatic vein (iliac level and pampiniform plexus) was perfomed in the same patients during a surgical protocol for varicocelectomy. In order to further evaluate which of the two sampling points is more useful to investigate testicular secretion, we have performed both forms of sampling in 4 volunteers given an HCG stimulation 24 h before the surgical procedure. It was found that levels of testosterone (T) and 17 alpha-hydroxyprogesterone (17-OHP) were higher in the pampiniform plexus (scrotal) than at the iliac sampling point (T scrotal 1,168.343 +/- 142.65 nmol/l, iliac 850.63 +/- 143.411 nmol/l, n = 21, p less than 0.01; 17-OHP scrotal 260.130 +/- 43.14 nmol/l, iliac 164.46 +/- 31.02 nmol/l, n = 17, p less than 0.01). This indicates that spermatic blood collected at the scrotal sampling point has received more blood coming from the testis than the blood collected at the iliac point. We did not observe significant differences in progesterone and delta 4-androstenedione (delta 4) levels between the two samplings. The T/delta 4 ratio was significantly lower in the iliac than in the scrotal sampling (T/delta 4 scrotal 31.420 +/- 6.69; iliac 15.41 +/- 3.84; p less than 0.05). After HCG stimulation, testosterone concentrations were higher in the pampiniform plexus than in the iliac sample. This suggests that the first sampling point is more proper for studying testicular secretion.(ABSTRACT TRUNCATED AT 250 WORDS)     

Three-dimensional organisation of the vasculature of the rat spermatic cord and testis

Summary The vascular architecture of the rat testis and spermatic cord was studied by a corrosion cast technique combined with scanning and transmission electron microscopy, and light microscopy. The casts preserve the endothelial impressions of the vessels and enable them to be differentiated into the various vascular components. Frequent arterio-arterial anastomotic arcades and occasional arterio-venous anastomotic channels are seen. A well defined hexagonal pattern of intertubular and peritubular vessels surround the seminiferous tubules. Prominent large endothelial nuclei protrude into the arterial lumina at branching sites, but their functional significance is not known. The outermost vascular layer of the testis consists of large veins, venules, and capillaries, but lacks any arterial branches; it also contains loosely arranged veno-venous anastomotic networks. We have named this vascular layer the sub-albugineal venous plexus. The testicular artery increases in luminal diameter as it approaches the testis. The periarterial capillary plexus, which lies between the pampiniform plexus and the testicular artery, is drained by two types of venules.     

Gamma glutamyl transpeptidase in the vasculature of the rat testis

Activity of gamma glutamyl transpeptidase (GGT) in the testes of mature and prepuberal rats was investigated histochemically and biochemically. Histochemically, the enzyme activity was localized predominantly in the arterial and arteriolar endothelium and was absent from the capillaries and the seminiferous tubules. The activity in the arterial endothelium extended to the testicular artery on the surface of the testis and in the spermatic cord, but the veins in both the pampiniform plexus and on the testicular surface were negative. The endothelium of the testicular artery was already faintly positive at birth, and the activity increased during the second and third postnatal week during the branching and remodeling of the intratesticular arteries and arterioles. Activity of GGT was estimated quantitatively after dissection of the testis into tubular and interstitial tissue. The enzyme activity was very low in the tubules. It was fivefold stronger in the interstitium, and this activity was further enhanced by pretreatment of the dissected tissue with collagenase to remove the Leydig cells.     

电刺激猫睾丸神经对睾丸睾酮分泌和血流速度的影响

本研究以睾丸神经分布丰富的成年雄性家猫为实验动物,采用２５Ｈｚ的强脉冲（５０－７０Ｖ）或弱脉冲（２０－２５Ｖ）刺激其睾丸精索上神经（ＳＳＮ）和下神经（ＩＳＮ）,并对其左侧睾丸静脉做导管以便测定睾丸睾酮分泌及血流速度等生理参数。结果表明,对ＳＳＮ进行电刺激,睾丸静脉血流速度在强刺激期间立即下降４４．８７％,但刺激之后又迅速恢复,而在弱刺激期间虽未发生变化,但刺激之后却显著减少２７．２５％;睾酮分泌在强刺激期间虽然下降４２．０１％,但刺激之后又平均增加２．５倍,相反,它在弱刺激期间增加８７．３３％,并且在刺激之后继续增加,最高时比刺激前平均增加４倍。与ＳＳＮ不同,对ＩＳＮ进行电刺激,血流速度虽然在强刺激期间升高１２．３１％,而刺激之后却呈下降趋势,然而,它在弱刺激期间和刺激之后却都未发生显著变化;睾酮分泌则无论是用强或弱刺激均未出现显著变化。因此,本研究结果表明,神经系统直接参与调节睾丸睾酮的分泌,为进一步深入研究神经与睾酮分泌之间的关系提供了可靠的依据。     

New methods of X-ray surgical diagnosis and treatment of varicocele in children and adolescents

The authors studied 520 patients with left-sided varicocele by left-sided phleborenotesticulography of Doppler ultrasonography, tensiometry of the left renotesticular venous system, blood gas composition, hormonal parameters, and etc. They present rationale for and evidence illustrations of aortomesenteric compression of the left renal vein, left-sided phleborenal hypertension prior to and after surgery for endovascular occlusion of the left testicular vein, before and following intervenous proximal testiculoiliac venous bypass surgery. The data of andrological dysfunction in patients with varicosis of the pampiniform plexus and spermatic cord (varicocele) are presented. An algorithm of examination and treatment of this cohort of patients, by using both miniinvasive techniques (for X-ray endovascular occlusion of the temporal veins under local anesthesia) and high tech operations using microsurgical techniques (testiculoiliac venous anastomosis), is outlined.     

Heritable testicular hypoplasia in Nguni (Bos indicus) bulls: vascular characteristics and testosterone production.

The biased unilateral occurrence of heritable gonadal hypoplasia was investigated by examining the gross- and microanatomy of the testicular artery and vein, testicular blood flow and testicular testosterone secretion in normal Nguni bulls and in Nguni bulls showing unilateral left, unilateral right and bilateral hypoplasia of the testis. A high incidence of branching of the testicular artery was found ipsilateral to hypoplastic testes. The branching occurs a short distance from the dorsal aorta: one branch proceeds to the testis, the other to the ipsilateral kidney. The association between arterial branching to the kidney and ipsilateral hypoplasia of the testis held for both unilaterally left and unilaterally right hypoplastic bulls. Variations in the anatomy of the testicular vein occurred in both normal and hypoplastic bulls but there was no specific association between the variations and ipsilateral hypoplasia. The lumen diameter of the testicular artery or branch correlated with testis mass. Wall thickness of the artery ipsilateral to hypoplastic testes was not different from that in normal bulls, discounting hyperplasia of the endothelium. Total blood flow to the testis correlated with testis mass. The secretion rate of testosterone from hypoplastic testes was lower than that of normal testes but there was no difference when compared on a unit mass basis.     

Sperm production, testicular size, serum gonadotropins and testosterone levels in Merino and Corriedale breeds

The relationships between testis size, hormone secretion and sperm production were studied during the spring (December) and autumn (May) in rams of two breeds with different breeding seasons and body weights (Corriedale and Australian Merino) maintained on native pastures and under natural photoperiods in Uruguay. Blood samples were collected at 20-min intervals during a 260-360-min period in 13 rams (four Corriedale, nine Australian Merino) during the late spring and autumn. Rams were weighed and testis size was estimated by orchimetry at each time period. Sperm production was estimated during a 2-week period, 2 months before blood collection and during each week following every blood collection. There was no relationship between testicular size and sperm production measured at the same time, nor between live weight and sperm production. In contrast, testicular volume during the late spring was correlated with sperm production in the autumn (r = 0.65; P = 0.02). The autumn serum LH was higher in Corriedale than in Merino rams. LH pulsatility was unaffected by season, but LH pulse frequency tended to be higher in Corriedale than in Merino rams, particularly in the late spring (2.37 versus 1.56 pulses/6 h; P = 0.08). Serum testosterone concentration was similar in both breeds and seasons. FSH levels were higher in the late spring than in the autumn in both breeds (Corriedale: 2.83 +/- 0.48 versus 2.17 +/- 0.24 ng x mL(-1); Merino: 2.23 +/- 0.24 versus 1.88 +/- 0.17 ng x mL(-1)). FSH and testosterone concentrations during the late spring were positively correlated with autumn sperm production (P = 0.07 and P = 0.03, respectively). In conclusion, the present experiment suggests that LH secretion is not a good parameter for the prediction of sperm production. In contrast, in our conditions (breeds and native pastures) testicular size and testosterone or FSH concentrations from the late spring may be used to predict sperm production in the autumn.     

Color Doppler ultrasound evaluation of testicular blood flow in stallions

The objectives of this study were to evaluate the potential use of color Doppler ultrasound to characterize blood flow to the stallion testis, and to establish reference values for Doppler measures of blood flow in the testicular artery of the stallion. Both testes from each of 52 horses were examined using a pulsed-wave color Doppler ultrasound with a sector array 5/7.5 MHz transducer with a 1mm gate setting. Peak systolic velocity (PSV), end diastolic velocity (EDV), resistive index (RI), and pulsatility index (PI) of the testicular artery were measured in each of two locations, the convoluted aspect (spermatic cord) and the marginal aspect of the artery (on the epididymal edge of testis). We found that: (1) all measures were obtainable; (2) except for EDV, the majority of the measures were higher at the cord location than at the marginal aspect of the artery (P < 0.05); and (3) measures for left and right testes were similar (P > 0.10). Resulting measures from 41 of these stallions (82 testes) that appeared free of testicular pathology provide useful reference values for clinical evaluation. Evaluation of 11 cases with testicular pathology suggested further investigation of possible effects of these various conditions on testicular blood flow and testicular function.     

Vascular supply of the testis of the camel (Camelus dromedarius).

The origin, pattern of distribution and the length of the convoluted part of the testicular artery were examined by blunt dissection and by the preparation of arterial casts with vinylite. The testicular artery originates from the abdominal aorta just cranial to its bifurcation and forms compact coils and reveals a tortuous course in the region of the pampiniform plexus and along the attached border. The artery divides at the caudal extremity of the testis into 2--4 branches. The epididymal artery, which is a branch of the testicular artery, was seen to anastomose with the deferential artery, but no anastomosis occurs between these arteries and the testicular artery. The convoluted part of the testicular artery was 20 cm in length, but when unravelled totalled 240 cm. This is not affected by seasonal variations. The possible significance of these results was discussed and compared with similar findings of other mammals.     

Testicular function and Leydig cell ultrastructure in long-term bilaterally cryptorchid rams

This study was conducted to investigate the effects of bilateral cryptorchidism induced in adult rams on testicular function and Leydig cell ultrastructure. The results indicated that long-term bilateral cryptorchidism resulted in decreased testicular size, degeneration of seminiferous tubules, elevated serum LH levels, maintenance of normal testosterone concentrations in peripheral and spermatic vein serum, impairment of the magnitude and duration of androgen response to exogenous luteinizing hormone (LH), a 13-fold reduction in total number of Leydig cells/paired testes, and a 3-fold hypertrophy in the average size of remaining Leydig cells. Based on quantitative morphometry, the hypertrophied Leydig cells exhibited significant increases in the volume of intracellular organelles, including the cell nucleus, mitochondria, smooth and rough endoplasmic reticulum, lysosome-like bodies and lipid vesicles. Quantitatively, the hypertrophy alone was not enough to offset the loss in number of Leydig cells and was insufficient to explain the maintenance of normal levels of testosterone in jugular and spermatic venous blood. The additional mechanisms responsible for production of normal serum testosterone levels in the cryptorchid ram remain to be elucidated.     

Local transfer of testosterone and aromatase activity in the spermatic cord in wild boar/pig hybrids in short-daylight and long-daylight periods

The local transfer of testosterone (T) and immunolocalization of cytochrome P450 aromatase (P450arom) in the spermatic cord vessels of ten male wild boar × domestic pig hybrids were examined in December (short-daylight period) and June (long-daylight period). Total T concentration was determined in the jugular vein (JV) and free T concentration was estimated in the common carotid artery (CA), branches of the testicular artery supplying the testis (TA) and epididymis (EA), as well as in testicular veins draining blood from the testis (TV) and spermatic cord (SV). P450arom was immunolocalized in the arterial and venous vessels of the spermatic cord. The concentrations of total T in the JV and free T in the CA did not differ between the examined periods. However, in December, free T concentrations in the TA and EA were higher (p < 0.01–0.001) than in the CA. In June, free T concentration was higher (p < 0.01) in EA than in CA and TA. The concentrations of free T in the TV and SV were higher (p < 0.001) than in the JV regardless of the period. Also, free T concentration in the SV was higher (p < 0.05) in June than in December. P450arom was expressed in all layers of the arterial and venous vessels of the spermatic cord. In June, the intensity of the P450arom staining was higher than in December. The results suggest that the local supply of the male reproductive organs with steroid hormones operate in the hybrids of wild boar × domestic pig. This supply includes the local transfer of testosterone and the P450arom action.     

Microvascular transposition of the arterial supply to the testis of the boar.

The origin of the arterial supply to a testis was changed in 7 boars with a microsurgical technique. A. testicularis was connected, end to side, to a branch of the femoral artery. The capillary blood flow was unchanged, indicating viable transplants. The temperature difference between testis and body disappeared after the surgery, indicating an interruption of the heat transfer in the pampiniform plexus. The lower values of the histological score and the possibly lower peripheral plasma concentration of testosterone after the arterial by-pass may indicate a physiological importance of the counter current exchange.     

Ultrasonographic appearance of clinically healthy testicles and epididymides of rams

The clinically healthy testicles and epididymides of 31 rams were imaged inside and outside the breeding period, by using a real time ultrasound scanner. A scanning technique based on multiple imaging planes from the caudal and the lateral surface of the genitalia was employed. Optimum imaging was achieved by using a 6.0 MHz frequency sector transducer. The testicular parenchyma appeared homogeneous with a coarse medium echo-pattern. The mediastinum testis was present in 87% of rams and 77% of testicles; its median echogenicity score was 2 (range: 0-3) among rams aged 13 months or older and 1 among rams aged less than 13 months (P = 0.001). The tail of the epididymis was always clearly visible; it appeared less echoic than the testicular parenchyma and with a heterogeneous structure. The epididymal body was not visible, whilst the epididymal head was consistently partially imaged. The pampiniform plexus was clearly imaged as a dome-shaped structure masking the upper part of the head of the epididymis. The scrotal septum was seen in lateral sonograms as a highly echogenic line between the testicles. The scrotal skin formed a thick hyper-echoic peripheral structure.     

Vascular morphology of the bovine spermatic cord and testis

Summary The highly coiled testicular artery within the bovine spermatic cord has a constant luminal diameter but a continuously decreasing mural thickness. The pampini form plexus is composed of three interconnected venous networks differing in mesh sizes and calibres. The large veins of the first network display pouches and permanent constrictions, which may serve as throttle devices. The constitutents of the third network are venules or venous capillaries with diameters between 10 and 20 m; they favor a periarterial position or even occupy the media-adventitia border of the testicular artery. All plexus veins are devoid of valves. The existence of true arteriovenous anastomoses between smaller branches of the testicular artery and plexus veins was established by serial sections. The vascular morphology of the spermatic cord is discussed with special attention to a postulated venous-arterial steroid transfer in this region.Supported by the Deutsche Forschungsgemeinschaft and the Stiftung zur Förderung der wissenschaftlichen Forschung an der Universität Bern     

睾丸去神经对大鼠半去势诱导的睾酮代偿性分泌的影响

在成年大鼠,半去势可以在促性腺激素没有明显改变的情况下导致睾丸静脉血液中睾酮浓度代偿性增加,其机理尚不明了。本研究以成年大鼠为实验动物,检验睾酮的代偿性增加是否受到睾丸去神经的影响。睾丸去神经（ｉｎｆｅｒｉｏｒ ｓｐｅｍａｔｉｃ ｎｅｒｖｅｓ,ＩＳＮ或ＩＳＮ ｐｌｕｓ ｓｕｐｅｒｉｏｒ ｓｐｅｒｍａｔｉｃ ｎｅｒｖｅｓ,ＩＳＮ－ＳＳＮ）手术２周后开始半去势实验,半去势之前和半去势之后６和２４ｈ,     

Observations on the vasculature of the reproductive tract in some Australian marsupials

The origin, distribution and structure of the blood vessels of the female reproductive tract and the testis of the brush possum (Trichosurus vulpecula) were studied using latex and silicone rubber casting and histological techniques. Latex casts of the vessels of the female tract were also studied in five macropod species – Macropus giganteus, M. eugenii, M. agilis, Megaleia rufa and Thylogale billardierii, and in the common wombat (Vombatus ursinus). The female reproductive tract in the brush possum was supplied and drained by four major sets of paired vessels – ovarian, cranial urogenital, caudal urogenital, and internal pudendal arteries and veins. These vessels formed substantial anastomoses with one another on each side of the midline, and also across-the-midline anastomoses. The proximal part of the ovarian artery ran in close apposition to the ovarian vein, which received one or more large uterine branches. In its distal protion the ovarian artery gave rise to a leash of small, tortuous ovarian branches, which wound around and between the plexiform ovarian veins. The testicular arteries and veins in this species also ran in close apposition to one another. Both arteries and veins branched into many smaller, mildly tortuous, parallel vessels in the spermatic cord, which reunited before entering the testis. The blood vessels of the reproductive tract in all of the macropod species studied, and in the common wombat, were basically similar to those of the brush possum. The intimate structural relationships between ovarian arteries and veins, and their ovarian branches, in these marsupials are suggestive of specializations for counter-current exchange between venous and arterial blood. However, in contrast to those of the testicular vessels where heat exchange is a demonstrated function, their physiological significance remains unknown.     

Synthesis and aromatization of 19-norandrogens in the stallion testis

The results of the measurement of 19-nortestosterone in the testiscular artery and vein of the stallion, the very low levels of this steroid in the peripheral blood of geldings and the similar patterns of increase in the peripheral levels of 19-nortestosterone and testosterone after hCG stimulation, show that 19-nortestosterone, like testosterone, is essentially synthesized in the testis. This testicular origin was confirmed by the ability of testicular tissue to synthesize 19-norandrogens from [4-14C]androgens in vitro. 19-Nortestosterone was 50% conjugated in the peripheral blood and almost entirely conjugated after biosynthesis in vitro. The sequence of appearance of steroids in the peripheral blood after a single injection of 10,000 IU hCG suggests that, in the equine testis, 19-norandrogens are produced by a specific C10-19 desmolase (estrene synthetase), stimulable by hCG. 19-Nortestosterone was aromatized into estradiol-17 beta by stallion testicular microsomes. The affinity of the aromatase for 19-nortestosterone was very low compared to that for testosterone. At low and presumably physiological levels, and at a high testosterone/19-nortestosterone ratio, testosterone did not inhibit 19-nortestosterone aromatization by more than 53%. Thus, 19-nortestosterone may be aromatized in vivo in the testis in spite of the endogenous concentrations of androgens. However, the low velocity of 19-nortestosterone aromatization by testicular microsomes at roughly physiological concentrations suggests that 19-norandrogen aromatization may only participate slightly in the testicular estrogen production. These results suggest that in the equine testis, two aromatizing enzyme systems may exist: one which aromatizes both androgens and 19-norandrogens, and a minority system more specific for 19-norandrogens.     

A simple technique for collecting blood of testicular origin: application to in vivo studies on testicular steroidogenesis in rats and Macaca fascicularis

A technique for rapidly collecting blood of testicular origin is described, one which can provide sufficient plasma amounts to investigate some steps of testicular steroid biogenesis in vivo in 2 species. In adult male rats, testosterone (T), androstenedione (4A) and 5-androstenediol (5AD) were determined in pampiniform plexus testicular venous blood (PPTV) and peripheral (PV) blood samples before and 2 h after human Chorionic Gonadotropin (hCG). PPTV concentration of 5AD was 0.83 +/- 0.1 ng/ml (mean +/- SEM) with a PPTV/PV ratio of 7.0 +/- 1.0, comparable to a PPTV/PV ratio for 4A of 5.8 +/- 1.8. After hCG, PPTV concentration of 5AD significantly increased to 1.28 +/- 0.15 ng/ml (P less than 0.05). Those data are in favor of a participation of 5-ene pathway to testicular biogenesis of T associated to a 4-ene pathway which is predominant. In adult male Macaca fascicularis, spermatic vein (SV) concentrations of 5AD and 4A were comparable (3.0 +/- 1.2 vs 4.3 +/- 1.0 ng/ml) as well as SV/PV ratios under basal conditions (3.5 +/- 0.9 vs 5.1 +/- 0.1), as well as 48 h after hCG, confirming in vivo that both 5-ene and 4-ene pathways are involved in testicular T biogenesis. Testicular production of estradiol (E2), estrone (E1) and their sulfates E2S and E1S showed a SV/PV ratio significantly higher than 1 (3.4 +/- 0.6; 2.4 +/- 0.1; 1.7 +/- 0.2 and 1.6 +/- 0.2, respectively).