Testicular Arterial Blood Flow Research Articles

Testicular arterial blood flow volume in predicting semen improvement following microscopic subinguinal varicocelectomy.

Varicocele is a significant but treatable contributor to male infertility. The efficacy of varicocelectomy in improving sperm quality is not consistent, with only 60-80% of patients experiencing improved semen quality. This prospective cohort study aimed to evaluate the effect of microscopic subinguinal varicocelectomy (MSV) on testicular arterial blood flow volume (TABFV) and to determine the value of preoperative TABFV in predicting the outcome of MSV. Patients with varicocele who underwent MSV at the same clinical center between July 2020 and April 2023 were enrolled. All patients underwent ultrasound assessment and at least one semen analysis before and after MSV. Both univariate and multivariate logistic regression analyses were performed to assess the association between pre-MSV variables and semen improvement after MSV. Subsequently, a diagnostic model was developed. This study enrolled 96 patients with varicocele, including 31 who showed semen improvement after MSV and 65 who did not. The postoperative semen-improved group demonstrated a significant increase in TABFV of the right testis (TABFV-R) and left testis (TABFV-L) (P<0.001). Notably, the postoperative TABFV-L was more than twice the preoperative TABFV-L. Preoperative TABFV-R and a combination of subclinical right-sided varicocele were found to be associated with semen improvement after MSV, and a diagnostic model was developed using these two variables. The diagnostic model exhibited satisfactory performance, with an area under the curve (AUC) of 0.824 [95% confidence interval (CI): 0.735-0.913], which was further validated internally yielding an AUC of 0.824 (95% CI: 0.726-0.900). Additionally, calibration analysis confirmed that the diagnostic model was well calibrated, and the Hosmer-Lemeshow test resulted in a P value of 0.794. The decision curve demonstrated that using this proposed nomogram would yield a net benefit if the threshold probability for semen improvement after MSV exceeded 10%. TABFV-L demonstrated potential utility in clinical practice for assessing outcomes of MSV, and the diagnostic model incorporating TABFV-R and a combination of right-side varicocele performed well in predicting improvements in semen parameters following MSV.

Ultrasonographic Assessment of Testicular Biometry and Arterial Blood Flow in Pre- and Postpubertal Miranda Donkeys: Correlations With Semen Quality Parameters.

The main goals of this study were to document and compare the normal ranges of testicular haemodynamic parameters in pre- (aged 8-12 months; n = 4) and postpubertal (aged 24-259 months; n = 16) Miranda donkeys in the breeding season, and to correlate animal biometric data and testicular Doppler indices with basic semen quality parameters of sexually mature jacks. Colour and pulsed-Doppler ultrasonography were employed to assess blood flow in the left and right distal supratesticular artery (DsTA) and their marginal branches (marginal arteries-MA). Peak systolic velocity (PSV), end diastolic velocity (EDV), pulsatility index (PI) and resistive index (RI) were evaluated in both blood vessels, and TAMV (time-averaged mean velocity), TABF (total arterial blood flow) and TABF rate (TABF-R) were calculated for MA. The mean diameter of MA was greater (p < 0.05; 0.24 ± 0.05 vs. 0.19 ± 0.05 cm; mean ± SD) but TABF-R was less (p < 0.05; 0.004 ± 0.004 vs. 0.02 ± 0.01 mL/s/cm3) in sexually mature donkeys compared with prepubertal animals. Apart from RI values for the right testicle of prepubertal donkeys, PI and RI were consistently greater (p < 0.05) in DsTA compared with MA. Significant correlations were found among select biometric and haemodynamic attributes of the testes (height, width and length, TV, TTV and PSV-ST) and ejaculate characteristics (volume, sperm defects-total, head and midpiece) in sexually mature donkeys (n = 8). The present results highlight the importance of scrotal ultrasonography for the reproductive assessment of jacks and provide reference values, based on the available subpopulation of Miranda donkeys that can be used in their clinical and reproductive management and research, or conservation programmes.

Hemodynamic evaluation of the testicular artery in stallions with spermatic cord torsion

Testicles are supported by spermatic cord and show some mobility within the scrotum. Excessive testicle mobility can result in rotation around its vertical axis, which may result in cord strangulation and reduction of blood perfusion (Filho and Oliveira, ABCMED. 2012). Depending on duration and severity of torsion, a reduction in diastolic velocity or retrograde diastolic flow may happen and lead to the absence of arterial flow, as a result of increased resistance to blood flow (Dogra et al., Journal of Clinical Ultrasound. 2001;29:105-108). Retrograde diastolic blood flow has been detected in stallions with 180° spermatic cord torsion (Pozor and McDonnel, Theriogenology. 2004;61:799-810). The objective of the present study was to evaluate testicular artery blood flow in stallions with 180° spermatic cord torsion in comparison to stallions with testis not affected by spermatic cord torsion. Both testis of 38 Mangalarga Marchador stallions were evaluated by spectral Doppler ultrasound. Animals with normal testis were divided into two experimental groups according to their age to verify if there would be any differences between groups: Normal Young, 30 months-4 years old (NY, n=10) and Normal Adults, 6-9 years old (NA, n=10). Similarly, animals with unilateral 180° spermatic cord torsion were divided into: Young with torsion, 30 months-4 years old (TY, n=10) and Adults with torsion, 6-9 years old (TA, n=8).For Doppler evaluations, spectral mode, resistance and pulsatility indexes (RI and PI, respectively), systolic peak velocity (SPV), end-diastolic velocity (EDV) and timed average mean maximum velocity (TAMMV) were measured at the supratesticular (Supra) and capsular (Cap) arteries. Stallions were evaluated during the reproductive season and were restrained without sedation. For statistical analysis, overall effect and pairwise testing with Šidák correction was performed. The effect of the predictor variables presence of torsion, age group and side were assessed using mixed models, Pearson correlations were also applied to assess the association between pairs of variables. For young stallions, when normal testis (n=20) were compared to rotated testis (n=15) and contralateral (n=5), rotated testis showed lower Supra RI than normal testis (P<0.001). For adult stallions, contralateral testis (n=7) Supra EDV were lower than normal testis (n=20) (P<0.001). Findings showed blood flow changes due to torsion in rotated testis and its contralateral. Therefore, these parameters should be considered to assess damage caused by torsion of the spermatic cord because of impaired testicular perfusion. Findings reinforce the theory of a reduced blood perfusion not only for the rotated testicles, but also for the contralateral one.

Effect of Acute Melatonin Injection on Metabolomic and Testicular Artery Hemodynamic Changes and Circulating Hormones in Shiba Goats under Sub-Tropical Environmental Conditions.

The beneficial effects of melatonin were investigated to mitigate various detrimental effects and toxicity on reproductive performance. The present study aimed, for the first time, to explore the effect of intravenous melatonin injection on testicular artery hemodynamics (TH) and metabolomic changes, reproductive hormones in heat-stressed bucks. Ten bucks were randomly split into two groups (five each): (1) the melatonin group, treated with a single intravenous dose of melatonin solution containing 10 mg melatonin each, and (2) the control group, which was treated with 10 mL of the vehicle without melatonin. Changes in the TH at the level of the supra testicular artery (STA) were assessed by triplex ultrasonography just before (0 h) and at 0.5, 2, 7, 24, and 168 h after melatonin or vehicle administration. Doppler velocity parameters of peak systolic velocity (PSV; cm/s), end-diastolic velocity (EDV; cm/s), and time average maximum velocity (TAMAX; cm/s) were measured. Doppler indices (resistive index; RI and pulsatility index; PI), systole/diastole (S/D) ratio and total arterial blood flow volume (TABFV; ml/minute) were measured. Peripheral concentrations of FSH, LH, inhibin, melatonin, testosterone (T), estradiol (E2), and cortisol were measured just before injection (0 h) and at 0.5, 2, 7, and 24 h and daily up to day 7 post administration in both groups. Results revealed reductions in the RI values and increases in the TABFV in the melatonin group compared to the control one, especially 2 h after administration. Significant increases in concentrations of FSH, T, E2, and melatonin and decreases in cortisol and inhibin in the melatonin group compared to the control one. Plasma metabolomic analysis at 2 h indicated the up-regulation of L-glutamine, L-arginine, sorbitol, D-glucose, ascorbic acid, and ornithine and the down-regulation of D-xylose, D-arabitol, ribitol, and oleic acid in the melatonin versus the control group. In conclusion, acute administration of melatonin (10 mg IV) enhanced testicular artery blood flow and plasma reproductive hormones in the Shiba goat under heat-stress circumstances.

Asinara male donkey (Equus africanus asinus var. Albina) and stallion (Equus ferus caballus) reproductive characteristics: Correlations between testicular blood supply and sperm production

The Asinara donkey is a rare small albino variety of feral donkey listed as "critical" by the Food and Agriculture Organization of the United Nations (FAO) and by the Domestic Animal Diversity Information System (DAD-IS) in 2022. The objectives of the present study were to evaluate the reproductive characteristics of healthy male Asinara donkeys through andrological evaluation and testicular echo-color-Doppler examination to assess correlations between testicular blood supply and sperm production and to compare it with horse reproductive characteristics. Eight healthy donkeys and stallions were subjected to semen collection and evaluation, ultrasound and Doppler evaluation of the testicles and serum testosterone determination. The testosterone concentrations in donkeys were 1.42 ± 0.69 ng/ml while in horses were 1.90 ± 0.63 ng/ml within the normal values reported in these species. Horses had greater mean and total testicular volume, semen gel-free volume, and total sperm number than donkeys (P < 0.001). Blood flow analysis of the testicular artery in both locations was a relatively simple procedure. The waveforms recorded in a convoluted location (-con) of the testicular artery were characteristic of the high-resistance vessel, while in the marginal location (-marg) were of low-resistance. It was also recorded a gradual decrease in peak systolic velocity (PSV), resistive index (RI), pulsatility index (PI), mean velocity (MV) and testicular arterial blood flow (TABF) values along the peripheral course of the testicular artery. Therefore, donkeys had greater PSV-con (P ≤ 0.01), PSV-marg (P < 0.01), MV-con (P < 0.001), MV-marg (P < 0.01), testicular arterial blood flow rate (TABFr-con) (P < 0.001) and TABFr-marg (P < 0.01) than horses. Conversely, pulsatility index (PI-con) was higher in horses (P < 0.05). The comparative analysis between the Doppler parameters and the reproductive/seminal characteristics showed a positive correlation of TTBF-con with Testosterone (ρ = 0.976, p < 0.01 and ρ = 0.905, p < 0.01 in donkeys and horses, respectively), with Total Testicular Volume (ρ = 0.952, p < 0.01 and ρ = 1.000, p < 0.01 in donkeys and horses, respectively), and with Total spermatozoa concentration (ρ = 0.905, p < 0.01 and ρ = 0.813, p < 0.05 in donkeys and horses, respectively). Additionally, only in the donkey there was a positive correlation with Semen gel free volume (ρ = 0.881, p < 0.01) and Spermatozoa concentration × ml (ρ = 0.786, p < 0.05). The testosterone concentration was positively correlated in both species with Total testicular volume (ρ = 0.976, p < 0.01 and ρ = 0.905, p < 0.01 in donkeys and horses, respectively) and Total sperm concentration (ρ = 0.881, p < 0.01 and ρ = 0.976, p < 0.01 in donkeys and horses, respectively). It was also correlated positively with Semen gel free volume (ρ = 0.857, p < 0.01) and spermatozoa concentration (ρ = 0.762, p < 0.05) in donkeys. Finally, the PI-con (ρ = − 0.786, p < 0.05) was negatively correlated with Semen gel free volume in the donkeys. The results of this study show that Total Testicular Blood Flow is the parameter, together with testosterone, most positively correlated with testicular volume and total sperm concentration in both species. Furthermore, differences in both reproductive and testicular hemodynamic characteristics between the Asinara donkey and stallion are highlighted, suggesting that caution should be taken in transferring knowledge from one species to another. New data on reproductive aspects, seminal characteristics, testicular blood flow perfusion in healthy Asinara donkeys were reported and these may represent reference value for further research or clinical applications.

Testicular shape, scrotal skin thickness and testicular artery blood flow changes in bulls of different ages.

The aim of this study was to compare the biometric testicular characteristics, skin thickness and haemodynamics of the testicular artery of 12- and 24-month-old bulls using Doppler ultrasonography, the study was conducted using 48 indicus-taurus animals. The scrotal circumference (SC) and biometry characteristics of the bulls were measured to calculate the testicular volume. Doppler ultrasonography was used to obtain the haemodynamic values of the testicular artery. The skin thickness and volume were lower (p<.01) in the younger bulls (12months:4.68±0.68mm; 168.76±47.96cm3 ) versus 24months (5.05±0.89; 499.73±129.24cm3 ) animals (p<.01). During diastole, mean velocity was lower in the 12months (7.98±3.83) than in the 24months (11.37±4.15) animals (p <.05). The 12-month-old animals had higher pulsatility and resistivity indices (0.49±0.02; 0.51±0.20) compared to the 24-month-old animals (0.32±0.16; 0.40±0.15) (p < .05). The final testicular end velocity was lower in animals with long/moderate-shaped (L/M) (7.31±2.91) than in those moderate/oval-shaped (M/O) (11.48±3.88) testicles (p < .05). Animals with L/M testes presented higher pulsatility values and resistivity indices (0.51±0.05; 0.55±0.04) compared to animals with M/O shape (0.29±0.20; 0.36±0.15). We showed that the blood flow of the supra testicular artery between the two evaluated ages differed, and that 24-month-old bulls presented better thermoregulation capacity. Animals with a long/moderate testicular format presented a greater vascular resistance, which was imposed on the blood flow due to the anatomical differences in the testicular artery, resulting in lower velocity, and indicating better heat dissipation in this format.

Ageing changes testes and epididymis blood flow without altering biometry and echodensity in dogs

Senescence leads to deleterious effects in testicular function, sperm quality and fertility in dogs. There, however, are no consistent results of vascular changes in the testes and epididymis during natural ageing in dogs. The aim of this study, therefore, was to compare testes and epididymis blood flow, biometry and echodensity between young and senile dogs. Ten young dogs (1–4 years) and eight senile dogs (over 7 years) were selected and assigned to two experimental groups: Young Group and Senile Group. Dogs were evaluated using testicular and epididymis B-mode (dimensions and echodensity) and Doppler ultrasonography (tissue perfusion parameters and blood flow velocity of the testicular artery). There were no differences between experimental groups for the echographic evaluation of testicular and epididymis parenchyma and biometric variables. The dogs in the Young Group had greater (P = 0.02) testes vascularization score and greater (P = 0.06) testicular artery blood flow velocity than those in the Senile Group. Furthermore, the older dogs had a greater (P = 0.06) pulsatility index of the testicular artery than those in the Young Group. Ageing, therefore, seems to cause natural hemodynamical changes to the testicular artery, resulting in reduced blood flow (ischemia) and tissue damage. Testes and epididymis vascular characteristics, therefore, may represent the causal factors for changes in spermatogenesis and, as a consequence, negatively affect the sperm quality of older dogs. In conclusion, senescence alters testicular artery blood flow and vascularization of the testes, without changing testicular and epididymis ultrasonographic dimensions and echodensity in dogs.

107 Influence of chronic melatonin supplementation on bovine testis physiology

Abstract The objective was to evaluate the influence of melatonin supplementation on bovine testis biometrics, thermoregulation, and blood flow in two age groups. Mature and peri-pubertal bulls received four subdermal 24 mg melatonin implants (MEL; n = 5 and n = 6, respectively) or no implants (CON; n = 5 and n = 6, respectively) every 30 ± 4 d for 120 ± 5 d. Body weight, scrotal circumference (SC), testes temperature (average temperature of left and right testes as quantified with thermal imaging), and total testicular artery blood flow (TBF; total blood flow to left and right testes as measured with Doppler ultrasonography) were evaluated on d 60, 90, and 120 ± 4. On d 120, peri-pubertal bulls were castrated and total testes weight (TTW) determined. Data were analyzed using MIXED procedures of SAS specific for repeated measures with treatment, time, and the interaction as fixed effects and sire (peri-pubertal only) as a random effect. On d 120, peri-pubertal bull data were analyzed using MIXED procedures of SAS with treatment as a fixed effect and sire as a random effect, and relationships of TBF, SC, TTW, testes temperature, and ambient temperature assessed using CORR procedures of SAS. Body weight, testes temperature, TBF, and TBF as a proportion of SC changed over time in peri-pubertal (P &amp;lt; 0.05) but not mature (P &amp;gt; 0.05) bulls. On d 120, TBF was increased (P = 0.05) and TBF as a proportion of TTW tended (P = 0.10) to be increased in MEL (95.48 ± 14.63 mL/min and 0.29 ± 0.03 mL/min*g, respectively) compared to CON (65.06 ± 15.10 mL/min and 0.21 ± 0.03 mL/min*g, respectively) peri-pubertal bulls. TBF was positively correlated with SC (r = 0.59; P = 0.04) and TTW (r = 0.66; P = 0.02). Ambient temperature was positively correlated with testes temperature (r = 0.78; P &amp;lt; 0.01). No other differences were identified (P &amp;gt; 0.05). Limited alterations in testis physiology were observed in melatonin-supplemented bulls.

Assessment of Dog Testis Perfusion by Colour and Pulsed-Doppler Ultrasonography and Correlation With Sperm Oxidative DNA Damage

The assessment of testicular artery blood flow by colour and pulsed-Doppler ultrasonography is an important diagnostic technique to assess vascular perfusion. Recently, it has been suggested as a good predictor of sperm quality. On the other hand, through the alkaline Comet Assay, it is possible to quantify sperm oxidative DNA damage. The aim of this study was to evaluate the relationship between routine sperm parameters, testicular artery blood flow and oxidative DNA damage in canine sperm. Testicular ultrasonography and sperm collection were performed on 12 male dogs, with the animals being allocated into 2 groups, according to the classification of the ejaculates’ quality, as normozoospermic (N; n = 7) or non-normozoospermic (OAT; n = 5). Seven dogs aged between 1.5 and 8.0 years old were included in group N and 5 dogs, aged between 2.0 and 11.0 years old, were included in group OAT. The sperm-rich fraction of the ejaculates was evaluated for sperm routine parameters and DNA damage by comet assay. Colour and pulsed-Doppler ultrasonography were used to evaluate the blood flow of the supratesticular and marginal arteries of right and left testis. Group OAT presented higher levels of sperm oxidative DNA damage (A.U.) in comparison to group N (N:11.7 ± 9.9; OAT:34.2 ± 6.1; P< .001). The peak of systolic velocity was positively correlated with sperm concentration (r = 0.685; P= .005). The resistive and pulsatility indexes (RI and PI) of the supratesticular artery were negatively correlated with sperm membrane integrity (HOST+) (r = −0.594; P = .042; r = −0.612; P = .035, respectively). The end diastolic velocity (EDV) of the supratesticular artery was positively correlated with sperm concentration (r = 0.748; P = .005) and negatively correlated with sperm oxidative DNA damage (r = −0.766; P = .004). Our results suggest that the assessment of the testicular artery blood flow by colour and pulsed-Doppler ultrasonography could be a good predictor of sperm quality in dogs in terms of sperm concentration, membrane integrity and sperm oxidative DNA damage.

Correlation of testicular artery Doppler velocimetry with kinetics and morphologic characteristics of epididymal sperm in dogs

Sperm quality can be affected by a reduction in testicular blood flow, which can be measured by Doppler ultrasonography. The aim of this study was to correlate the Doppler velocimetry of the testicular artery with kinetics of the epididymal spermatozoa in dogs. Twenty-two dogs (44 testicles) were evaluated by Doppler ultrasonography in five regions of the testicular artery before orchiectomy. Spermatozoa were recovered by the epididymal tail compression technique and analysed for kinetics on a computer-assisted semen analysis (CASA system). Morphology (modified Karras) and sperm membrane integrity were analysed by eosin-nigrosine staining. Data were analysed by Pearson's correlation test (p<.01). The mean total motility was 69.0%±17.7, progressive motility was 43.7%±14.7, average path velocity (VAP) was 127.0µm/s±20.7, curvilinear velocity (VCL) was 221.0µm/s±31.1, and sperm velocity index (SVI) was 389.9±56.1. There were positive correlations between the peak systolic velocity (PSV) in the proximal supratesticular region with the SVI (r=.529), VCL (r=.555) and VAP (r=.473), and a negative correlation with the percentage of slow spermatozoa (r=-.463). The results suggest that the testicular artery blood flow velocity can positively affect the speed of spermatozoa movement. For the first time, we have correlated sperm kinetics with the Doppler evaluation of the testicular artery in dogs.

Examination of jackass (Equus asinus) accessory sex glands by B-mode ultrasound and of testicular artery blood flow by colour pulsed-wave Doppler ultrasound: Correlations with semen production.

The accessory sex glands play a major role in the production of seminal plasma, and testicular artery blood flow seems to strongly influence testicular function. However, very little ultrasound imaging of these organs has been undertaken in donkeys. The present work reports the results of such examinations in five jackasses along the year. The accessory glands were inspected by B-mode ultrasound while the testicular artery blood flow was assessed by colour pulsed-wave Doppler ultrasound. The testicular artery was examined at pampiniform plexus (PPT), supratesticular area (ST) and capsular artery (CA). Values were recorded for the total arterial blood flow (TABF), peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI), pulsatility index (PI) and time average maximum velocity (TAMV). Semen was obtained and assessed for sperm concentration, viability, abnormalities and motility using a CASA system. The bulbourethral glands, prostate and ductus deferens ampullae were relatively larger than in the stallion. Bulbourethral glands and ampullae sizes were inversely correlated with sperm motility. An reduction in blood flow between the level the PPP and the CA was observed, helping to reduce testis temperature and oxygen pressure. Blood flow at the CA showed the strongest correlation with semen production. PI and RI were positively correlated with the CASA motility variable STR (p=.02, p=.06) and sperm viability (p=.01), while sperm concentration (p=.05) correlated inversely with PSV, EDV, TAMV and TABF. EDV also correlated negatively with the CASA variables VSL, LIN, STR and VAP (p≤.05). PI and RI were also negatively correlated with testis length (p=.0093, p=-.0438).

Changes in testicular size, echotexture, and arterial blood flow associated with the attainment of puberty in Dorper rams raised in a subtropical climate.

There is a paucity of information on the relationships of testicular morphology, echotextural attributes, and blood flow dynamics with pubertal development of rams raised in a subtropical climate. Forty-five Dorper rams (24 rams aged 8-11months and 21 rams aged 12-24months) were examined using a portable ultrasound scanner connected to a 7.5-MHz transducer. Computer-assisted analyses of testicular ultrasonograms utilized commercially available Image ProPlus® analytical software. Spectral Doppler scans of testicular arteries were performed immediately after scrotal (B-mode) ultrasonography to determine peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI=[PSV-EDV]/PSV), and pulsatility index (PI=[SPV-EDV]/mean velocity) of the blood vessels. The length of the testes (9.7±0.3 compared with 9.0±0.2cm) and scrotal circumference (33.3±0.5 compared with 31.8±0.4cm) were greater (p<0.05) but testicular depth (4.5±0.1 compared with 4.9±0.08 cm) was less (p<0.05) in sexually mature compared with peripubertal rams. [Corrections added on 9 Jan 2019 after initial online publication: The testicular size values in the sentence were corrected.] There were no differences (p>0.05) between the two age groups of Dorper rams in blood flow indices of testicular arteries. Mean numerical pixel values (100.5±4.1 compared with 89.2±4.8) and pixel heterogeneity (25.6±0.6 compared with 23.6±0.5) of testicular parenchyma were greater (p<0.05) in peripubertal than in postpubertal rams. Semen volume was negatively correlated with PI of testicular arteries (r=-0.57, p=0.04). In summary, the attainment of sexual maturity in the rams of the present study was associated with significant changes in testicular length and depth, scrotal circumference, and parenchymal echogenicity/hetrogeneity but not in testicular volume and blood perfusion rates. Testicular artery PI can be used to predict the volume of ejaculate in rams.

151 Associations of Testicular Size and Arterial Blood Flow with Sexual Development and Semen Characteristics in Dorper Rams Raised in a Subtropical Climate

Spectral Doppler (velocimetric) indices are important indicators of blood perfusion and physiological status of internal organs. Doppler ultrasound is used in andrology to assess the blood flow in the testicular arteries, aiding in the diagnosis of scrotal disorders and abnormal spermatogenesis. It was proposed that blood flow indices measured in the testicular artery, namely, blood flow resistance and pulsatility index, were significant predictors of semen quality in clinically healthy dogs. There is a paucity of studies on the associations of testicular morphology and blood flow dynamics with spermatogenesis in growing rams. Forty-five Dorper rams (24 rams aged 8 to 11 months and 21 rams aged 12 to 24 months) were examined using a portable ultrasound scanner connectecd to a linear-array 7.5-MHz transducer. Measurements of the testes were taken with built-in electronic calipers on images containing the largest cross-sectional area of each testicle in 3 planes (coronal, sagittal, and transverse). Colour and spectral Doppler scans were performed immediately after scrotal ultrasonography to detect the testicular arteries and record the following velocimetric indices: peak systolic velocity (PSV, cm/s), end-diastolic velocity (EDV, cm/s), resistive index (RI = [PSV – EDV)/PSV], and pulsatility index [PI = (SPV – EDV)/mean velocity] of the blood vessels. The length (9.7 ± 0.3 v. 9.0 ± 0.2 cm; mean ± SD) of the testes and scrotal circumference (33.3 ± 0.5 v. 31.8 ± 0.4 cm) were greater (P &lt; 0.05) in sexually mature rams than in peri-pubertal rams. There were no differences (P &gt; 0.05) between the 2 age groups of Dorper rams in mean values for blood flow indices measured in testicular arteries. Semen was collected by ejaculation into the artificial vagina from 38% (8/21) of post-pubertal rams and 21% (5/24) of peri-pubertal animals (Chi-squared test; P &lt; 0.05). Semen volume was negatively correlated with PI of the testicular arteries (r = –0.57, P = 0.04). In summary, the attainment of sexual maturity in Dorper rams maintained in a subtropical climate was associated with significant elongation of testes but not with the changes in testicular volume and blood perfusion. Testicular artery PI was a significant predictor of semen volume in peri-pubertal and sexually mature rams. Based on this and several previous studies, B-mode ultrasonography combined with echotextural analyses of the epididymides and accessory sex glands and serum testosterone measurements provide more useful information on the progression of sexual maturation and present semen quality in rams than the ultrasonographic assessment of testicular dimensions and an array of blood flow indices.

Potential role of imaging in assessing harmful effects on spermatogenesis in adult testes with varicocele.

Varicocele is characterized by an abnormal dilatation and retrograde blood flow in the spermatic veins. Varicocele is the leading correctable cause of male infertility. Although it is highly prevalent in infertile men, it is also observed in individuals with normal fertility. Determining which men are negatively affected by varicocele would enable clinicians to better select those men who will benefit from treatment. To assess the functional status of the testes in men with varicocele, color Doppler sonographic parameters were evaluated. Testicular arterial blood flow was significantly reduced in men with varicocele, reflecting an impairment of spermatogenesis. An improvement in the testicular blood supply was found after varicocelectomy on spectral Doppler analysis. Testicular contrast harmonic imaging and elastography might improve our knowledge about the influence of varicocele on intratesticular microcirculation and tissue stiffness, respectively, providing possible information on the early damage of testicular structure by varicocele. Magnetic resonance imaging (MRI), with measurement of apparent diffusion coefficient has been used to assess the degree of testicular dysfunction and to evaluate the effectiveness of varicocele repair. Large prospective studies are needed to validate the possible role of functional sonography and MRI in the assessment of early defects of spermatogenesis in testes with varicocele.

Semen quality, testicular B-mode and Doppler ultrasound, and serum testosterone concentrations in dogs with established infertility

Retrospective examination of breeding records enabled the identification of 10 dogs of normal fertility and 10 dogs with established infertility of at least 12 months of duration. Comparisons of testicular palpation, semen evaluation, testicular ultrasound examination, Doppler ultrasound measurement of testicular artery blood flow, and measurement of serum testosterone concentration were made between the two groups over weekly examinations performed on three occasions. There were no differences in testicular volume (cm3) between the two groups (fertile right testis = 10.77 ± 1.66; fertile left testis = 12.17 ± 2.22); (infertile right testis = 10.25 ± 3.33; infertile left testis = 11.37 ± 3.30), although the infertile dogs all had subjectively softer testes compared with the fertile dogs. Infertile dogs were either azoospermic or when they ejaculated, they had lower sperm concentration, sperm motility, and percentage of morphologically normal spermatozoa than fertile dogs. Furthermore, infertile dogs had reduced sperm membrane integrity measured via the hypoosmotic swelling test. Infertile dogs had significantly lower basal serum testosterone concentrations (1.40 ± 0.62 ng/mL) than fertile dogs (1.81 ± 0.87 ng/mL; P < 0.05). There were subjective differences in testicular echogenicity in some of the infertile dogs, and important differences in testicular artery blood flow with lower peak systolic and end-diastolic velocities measured in the distal supratesticular artery, marginal testicular artery, and intratesticular artery of infertile dogs (P < 0.05). Notably, resistance index and pulsatility index did not differ between infertile and fertile dogs. These findings report important differences between infertile and fertile dogs which may be detected within an expanded breeding soundness examination.

Regional differences of testicular artery blood flow in post pubertal and pre-pubertal dogs.

BackgroundMeasurement of testicular artery blood flow is used in several species to evaluate reproductive function and testicular and scrotal pathology. In dogs there are inconsistent reports about normal flow in post-pubertal dogs and no information concerning pre-pubertal dogs. The aim of this study was to describe regional differences in testicular artery blood flow in clinically normal post-pubertal and pre-pubertal dogs with no history of reproductive tract disease.ResultsThe post-pubertal dogs produced normal ejaculates throughout the study. In all dogs the three different regions of the artery were imaged and monophasic flow with an obvious systolic peak and flow throughout diastole was observed on every occasion. The highest peak systolic velocity (PSV) and end diastolic velocity (EDV) were measured within the distal supra-testicular artery and marginal artery whilst the lowest PSV and EDV were measured within the intra-testicular arteries. Flow measurements were not different between left and right testes and were consistent between dogs on different examination days. Calculated resistance index (RI) and pulsatility index (PI) were lowest in the intra-testicular arteries.The pre-pubertal dogs had significantly smaller testes than the post-pubertal dogs (p < 0.05) and were unable to ejaculate during the study. The three different artery regions were imaged at every examination time point, and flow profiles had a similar appearance to those of the post-pubertal dogs. PSV, EDV, RI and PI showed a similar trend to the post-pubertal dogs in that values were lowest in the intra-testicular arteries. Notably, values of PSV, EDV, RI and PI were significantly lower (p < 0.05) in pre-pubertal dogs compared with post-pubertal dogs.ConclusionsThis study demonstrated important regional and pubertal differences in testicular artery blood flow of dogs, and form the basis for establishing baseline reference values that may be employed for the purposes of clinical diagnosis.

Doxorubicin-Induced Vascular Toxicity – Targeting Potential Pathways May Reduce Procoagulant Activity

IntroductionPrevious study in mice using real-time intravital imaging revealed an acute deleterious effect of doxorubicin (DXR) on the gonadal vasculature, as a prototype of an end-organ, manifested by a reduction in blood flow and disintegration of the vessel wall. We hypothesized that this pattern may represent the formation of microthrombi. We aimed to further characterize the effect of DXR on platelets’ activity and interaction with endothelial cells (EC) and to examine potential protectants to reduce DXR acute effect on the blood flow.MethodsThe effect of DXR on platelet adhesion and aggregation were studied in vitro. For in vivo studies, mice were injected with either low molecular weight heparin (LMWH; Enoxaparin) or with eptifibatide (Integrilin©) prior to DXR treatment. Testicular arterial blood flow was examined in real-time by pulse wave Doppler ultrasound.ResultsPlatelet treatment with DXR did not affect platelet adhesion to a thrombogenic surface but significantly decreased ADP-induced platelet aggregation by up to 40% (p<0.001). However, there was a significant increase in GPIIbIIIa-mediated platelet adhesion to DXR-exposed endothelial cells (EC; 5.7-fold; p<0.001) reflecting the toxic effect of DXR on EC. The testicular arterial blood flow was preserved in mice pre-treated with LMWH or eptifibatide prior to DXR (P<0.01).ConclusionsDXR-induced acute vascular toxicity may involve increased platelet–EC adhesion leading to EC-bound microthrombi formation resulting in compromised blood flow. Anti-platelet/anti-coagulant agents are effective in reducing the detrimental effect of DXR on the vasculature and thus may serve as potential protectants to lessen this critical toxicity.

Evaluation of testicular artery blood flow by Doppler ultrasonography as a predictor of spermatogenesis in the dog

The present study examines the relationship between reproductive and seminal characteristic with blood flow supply of the testis in male dogs by means of Doppler ultrasonography. Five male dogs were subject to a clinical examination, blood sampling, B-Mode and Doppler ultrasonography of the testis, semen evaluation at collections and after storage at 4°C for 24, 48 and 72h in three replicates 30days apart. Peak Systolic Velocity was positively correlated with testicular volume and negatively with live sperm at collections and after 24h. A negative correlation existed between Resistive Index and Pulsatility Index with total and progressive motility at collections and also after 24, 48 and 72h. Resistive Index and Pulsatility Index were also negatively correlated with the percentage of membrane intact sperms with curled tails at collections while the latter was positively correlated with End Diastolic Velocity. Moreover, positive linear correlations of weight with bilateral testicular volume and total sperm concentration and also between age and abnormal sperm at collections and after 24h were established. The results suggest that the Resistive Index and Pulsatility Index seem to be potential markers of seminal quality in dogs.

Association between serum inhibin-B levels and coronary artery disease in aging males

IntroductionAtherosclerosis is a systemic disorder. It is a frequent leading cause of coronary artery disease (CAD). Similarly, atherosclerotic vascular alterations could lead to testicular arterial blood flow reduction and impairment of testicular function with age. Inhibin-B has been validated as a valuable serum marker of testicular functions and its correlation with testicular volume was shown in some studies done before. The purpose of this study is to investigate the association between serum inhibin-B levels and CAD in elderly men.Material and methodsBetween March 2009 and March 2010, fifty-two 50-80-year-old consecutive patients with Gensini score over 20 and ejection fraction (EF) > 50% were included in the study as the CAD group. Fifty healthy men without any cardiac disease history were recruited as the control group. All patients in the CAD group who had indications for coronary artery angiography underwent selective coronary artery angiography.ResultsInhibin-B, total testosterone and testicular volume levels were found to be significantly lower in the CAD group in comparison with the control group (p = 0.004, p < 0.0001, and p = 0.001 respectively).ConclusionsIn this study, although no correlation was found in CAD patients between Gensini score and inhibin-B or testicular volume, inhibin-B levels and testicular volume were significantly lower in patients with CAD than in healthy men. In order to fully assess the relationship between serum inhibin-B levels and CAD, multi-centered prospective and longitudinal studies must be done in elderly male patients.

Doxorubicin-induced vascular toxicity: Targeting potential pathways to reduce procoagulant activity.

e13080 Background: In a former study in mice using the gonads as an end-organ prototype, we have characterized by real-time intravital imaging an acute deleterious effect of doxorubicin (DXR) on the gonadal vasculature, manifested by a reduction in blood flow and disintegration of the vessel wall. We hypothesized this pattern may represent the formation of microthrombi. We aimed to further characterize the effect of DXR on platelets’ function and to use potentially protectants to reduce DXR acute effect on the blood flow. Methods: 100 µg/mouse 24 hours and 1 hour prior to DXR treatment (8 mg/kg), or with eptifibatide (integrilin,75µg/mouse) 90min prior to DXR treatment. Testicular arterial blood flow was examined in real-time by pulse wave Doppler ultrasound. Platelet adhesion to confluent endothelial cells (EC) was evaluated following exposure of EC to DXR (100 µM) for 4h followed by exposure to whole blood under defined shear rates. Fixed platelets were immunostained by anti- CD41a antibody. DXR effect on platelet adhesion was determined by pre-incubation of platelet rich plasma for 15min with increasing concentrations of DXR and induction of aggregation by ADP. For in vivo study, mice were injected with either LMWH (Enoxaparin; Clexane). Results: There was a significant 3.6-fold increase in platelet adhesion to DXR-exposed EC (p&lt;0.002) reflecting the toxic effect of DXR on EC. Yet, significant DXR- dose dependent decrease in platelet aggregation was observed reaching up to 40% inhibition at 100 µM (p&lt;0.001). Testicular arterial blood flow was preserved as a result of pre-treatment with LMWH or eptifibatide prior to DXR (P&lt;0.01). Conclusions: DXR-induced acute vascular toxicity may trigger the coagulation pathway while enhancing platelet adhesion yet inhibiting massive aggregation, which result in compromised blood flow due to microthrombi formation. Anti-platelet/anti-coagulant agents appear to be effective in reducing the detrimental effect of DXR on the vasculature.