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Spectral wave-forms of testicular blood flow in the stallion. (a) Biphasic wave-form. (b) Monophasic waveform . (Color version of figure is available online.)
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Vascular disorders play an important role in male infertility. Various modalities of ultrasound examination can be applied to evaluate testicular vasculature and to objectively measure numerous parameters of testicular perfusion. This paper describes techniques of ultrasound examination of testicular vasculature in the stallion, using gray-scale, c...
Contexts in source publication
Context 1
... spectral analysis of the blood flow, a small gate size (1-2 mm) and angle correction between 30° and 60° should be set. After activating pulsed-wave mode (PW), a line with a small gate will appear on the screen. This gate has to be placed within the lumen of the longitudinal section of the vessel, running parallel to the line. The best insonation is reached when a direction of the blood flow is parallel to the ultrasound beam. The operator can manipulate with the po- sition of the probe to improve insonation. In addition to it, angle correction mode can be used. Pressing PW button again activates spectral analysis of blood flow velocities. A charac- teristic wave form of testicular blood flow in the stallion is biphasic with a high, systolic peak and a lower, diastolic peak (Fig. 4a). It may be also monophasic, with just one, systolic peak (Fig. 4b). Biphasic spectrum is characteristic for the proximal parts of the testicular artery (convoluted part - spermatic cord), and monophasic spectrum is often identi- fied in distal parts of this vessel (marginal part). Direct mea- sures of blood flow velocities are obtained from the graph (PSV, peak systolic velocity; EDV, end diastolic velocity; MV, minimum velocity). Additional parameters are calculated us- ing the ultrasound, built-in algorithm (TAM, time averaged maximum velocity; RI, resistance index; PI, pulsatility in- ...
Context 2
... spectral analysis of the blood flow, a small gate size (1-2 mm) and angle correction between 30° and 60° should be set. After activating pulsed-wave mode (PW), a line with a small gate will appear on the screen. This gate has to be placed within the lumen of the longitudinal section of the vessel, running parallel to the line. The best insonation is reached when a direction of the blood flow is parallel to the ultrasound beam. The operator can manipulate with the po- sition of the probe to improve insonation. In addition to it, angle correction mode can be used. Pressing PW button again activates spectral analysis of blood flow velocities. A charac- teristic wave form of testicular blood flow in the stallion is biphasic with a high, systolic peak and a lower, diastolic peak (Fig. 4a). It may be also monophasic, with just one, systolic peak (Fig. 4b). Biphasic spectrum is characteristic for the proximal parts of the testicular artery (convoluted part - spermatic cord), and monophasic spectrum is often identi- fied in distal parts of this vessel (marginal part). Direct mea- sures of blood flow velocities are obtained from the graph (PSV, peak systolic velocity; EDV, end diastolic velocity; MV, minimum velocity). Additional parameters are calculated us- ing the ultrasound, built-in algorithm (TAM, time averaged maximum velocity; RI, resistance index; PI, pulsatility in- ...
Context 3
... can manipulate with the po- sition of the probe to improve insonation. In addition to it, angle correction mode can be used. Pressing PW button again activates spectral analysis of blood flow velocities. A charac- teristic wave form of testicular blood flow in the stallion is biphasic with a high, systolic peak and a lower, diastolic peak (Fig. 4a). It may be also monophasic, with just one, systolic peak (Fig. 4b). Biphasic spectrum is characteristic for the proximal parts of the testicular artery (convoluted part - spermatic cord), and monophasic spectrum is often identi- fied in distal parts of this vessel (marginal part). Direct mea- sures of blood flow velocities are obtained ...
Context 4
... insonation. In addition to it, angle correction mode can be used. Pressing PW button again activates spectral analysis of blood flow velocities. A charac- teristic wave form of testicular blood flow in the stallion is biphasic with a high, systolic peak and a lower, diastolic peak (Fig. 4a). It may be also monophasic, with just one, systolic peak (Fig. 4b). Biphasic spectrum is characteristic for the proximal parts of the testicular artery (convoluted part - spermatic cord), and monophasic spectrum is often identi- fied in distal parts of this vessel (marginal part). Direct mea- sures of blood flow velocities are obtained from the graph (PSV, peak systolic velocity; EDV, end diastolic ...
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Citations
... A ultrassonografia em modo B (escala de cinza) é um método diagnóstico não invasivo que fornece importantes informações sobre a arquitetura interna de órgãos. A ultrassonografia do trato reprodutivo de garanhões é uma excelente ferramenta no diagnóstico de inúmeras afecções como granuloma espermático, epididimites (Held et al., 1990), criptorquidismo (Love, 1992), varicocele, estruturas císticas do epidídimo, aumento da espessura da túnica vaginal (Pozor, 2007) e neoplasias testiculares (Hunt et al., 1990). ...
... A veia central é encontrada na seção transversal como uma região circular hipoecóica e quando em seção longitudinal, é vista como uma linha ondulada. Já as veias do plexo pampiniforme têm diâmetros muito pequenos e não são facilmente identificadas (Pozor, 2007). ...
... Essa modalidade detecta a amplitude ou potência do sinal Doppler e é muito eficiente no diagnóstico de ausência ou fluxo sanguíneo deficiente. A quantidade de células sanguíneas em movimento no vaso, ou seja, a intensidade do fluxo é representada como um gradiente de cor laranja sobreposto sobre a imagem do ultrassom modo B, que varia de laranja escuro para um laranja claro, representando menor e maior intensidade, respectivamente (Pozor, 2007). ...
... Previous studies have shown that the haemodynamic parameters of blood flow within the testicular artery were associated with the testicular volume, spermatogenesis, and semen quality [19,20]. The testicular parenchyma is a highly metabolic tissue, in which any disturbance in nutrient and oxygen supply (through the blood supply) may adversely affect function and morphology [21]. ...
The objectives were (a) the study of haemodynamic parameters of blood flow within the testicular artery, (b) the assessment of differences in these parameters at different segments of the artery (i.e., sequentially, as the artery flows through different regions of the testis), and (c) the identification of potential associations with measures of testicular maturation. Eight healthy beagle-breed male dogs were monitored at fortnightly intervals from the 4th to the 40th week of life, by using clinical, seminological, and ultrasonographic (B-mode, pulsed-wave Doppler) examinations. Haemodynamic parameters were assessed at four different segments of the testicular artery: at the distal supra-testicular, the marginal testicular at the cranial pole of the testis, the marginal testicular at the caudal pole of the testis, and the intratesticular. The study period was divided into three time slots (pre-puberty, puberty, and post-puberty) depending on testicular maturation and sperm production. No clinically evident abnormalities were seen in any animal throughout the study. Semen ejaculates were first collected on the 28th week, and spermatozoa were first seen on the 30th week of life. The results of B-mode examination indicated that in all dogs, the echogenicity of the testicular parenchyma was homogeneous. The waveforms of the blood flow in the testicular artery were monophasic with systolic peaks, low diastolic flow, and low vascular resistance. Most cases of significant differences between the three age periods were noted for the comparison of the pre-pubertal to pubertal periods (n = 11); among the parameters studied, the blood volume (n = 9) showed most instances of significant differences; finally, most cases of significant differences were noted in the distal supra-testicular artery (n = 12). Correlations were mainly seen for the end diastolic velocity, the peak systolic velocity and the blood volume (each with two semen evaluation parameters). The distal supra-testicular and the marginal artery at the cranial pole of the testis are recommended as the most appropriate segments of the vessel for performing a Doppler examination in the testicular artery due to the adequate size and the clear spectral waveforms as early as the 12th week of age of the animals.
... An appropriate dose of xylazine was recommended in stallions as it does not induce prominent variations in testicular blood flow (Pozor and McDonnell 2002). However, higher doses of xylazine are not recommended to avoid sedating the horse heavily and to avoid someone getting accidentally kicked (Pozor and McDonnell 2002;Pozor 2007;Samir et al. 2021). Parental administrations of xylazine and ketamine combination in rabbits produced transient vasodilatation at the left common carotid artery and the abdominal aorta. ...
Under field conditions, sedation may be required for a full assessment of the reproductive potential of farm animals. The present study aimed to investigate the effect of xylazine sedation on testicular hemodynamics (TBF), echotexture, testicular volume (TV), and circulating hormones in goats. Sixteen male Shiba goats were sedated using the recommended dose of xylazine (0.05 mg/Kg BW). Testicular hemodynamics were evaluated using color-pulsed Doppler ultrasonography before and after sedation. Echotexture of the testicular parenchyma and TV were assessed using computerized image analysis. Concentrations of testosterone, estradiol (E2), inhibin, cortisol, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were measured using radioimmunoassay. There were no effects of xylazine sedation in TBF, TV, testicular parenchyma parameters, and concentrations of testosterone, inhibin, FSH, and LH (P ˃ 0.05). However, after sedation, there was significantly (P ˂ 0.05) lower cortisol and E2 concentration (42.88 ± 6.79 ng/ml and 2.47 ± 0.58 pg/ml, respectively) than before sedation (94.89 ± 13.74 ng/ml and 8.65 ± 1.79 pg/ml, respectively). The required time to perform the full scanning of the testis was significantly lower (8.50 ± 0.38 min) after xylazine sedation compared to the non-sedated goats (25.75 ± 1.14 min). In conclusion, xylazine sedation may be practically recommended for the evaluation of TBF in goats because it did not significantly alter velocities parameters and Doppler indices of blood flow within the testicular arteries. Most plasma hormones did not significantly change; however, E2 and cortisol were significantly reduced after xylazine administration.
... In rams, various degrees of testicular ischemia induced focal morphological changes in the testes (Markey et al. 1995). Pathological disorders affecting the testis's vasculature, such as varicocele or spermatic cord torsion, greatly reduced TBF and compromised testicular function in stallions (Pozor 2007). Importantly, a mild decrease in TBF has detrimental effects on early-stage spermatogenesis (Nolte et al. 1995;Bergh et al. 2001). ...
... There are some morphological variations between ruminants' testicular arteries and those of other animal species. The testicular artery in stallions, for example, travels in a wavy pattern along the epididymal edge (known as the marginal portion of the testicular artery), along the caudal testicular pole, and along the free edge of the testis as one to three branches (Collin 1973;Pozor 2007). The MTA encircles the testicular circumference completely along both borders (Elayat et al. 2014). ...
... On the opposite, little attention has been paid to the effect of seasonality on TBF. In stallions, increases in TBF have been reported in spring months as compared to winter months (Boyd et al. 2006;Pozor 2007). Increased TBF during the breeding seasons of stallions was coincident with increases in sperm production (Boyd et al. 2006). ...
In all organs, control of blood flow is important but might be particularly critical for testicular functions. This is because of the very low oxygen concentration and high metabolic rate of the seminiferous tubules, the physiological temperature of the testis, and its location outside the abdominal cavity. Many factors affect the characteristics of TBF in farm and companion animals, such as environment (thermal and seasonal effects) and physiological (species, breeds, age, body weight, and sexual maturity). Thermal environment stress has detrimental effects on spermatogenesis and consequently has more serious impacts on both human and animal fertility. Numerous studies have been performed to assess TBF in different animal species including bulls, rams, bucks, alpacas, stallions, and dogs with varied results. Hence, assessment of TBF by Doppler ultrasonography is of great importance to estimate the effect of high environment temperature on testicular functions. Also, differences observed in the TBF may result from different technical aspects such as the identification of the segment of the testicular artery to be examined. In the current review, we focused on the imperative roles of TBF in various animal species. Besides, we discussed in detail various factors that could affect TBF. These factors can significantly modify the TBF and thus should be considered when establishing reference values in farm animals for better clinical diagnosis. The information provided in this review is valuable for researchers and veterinarians to help them a better understanding of testicular hemodynamics for the proper evaluation of breeding soundness examination in males.
... In male rats, LH administration induced regulatory effects on testicular microcirculation, probably via an unidentified Leydig cell product, in a dose-dependent response [5] . In stallions, a single intravenous dose of hCG 50 0 0 to 60 0 0 IU, improved the testicular perfusion [6] through its effect on time-averaged maximum velocity, and total arterial blood flow rate (TABF). The mechanism by which hCG can affect testicular perfusion may be attributed to its effect through vasoactive substances such as nitric oxide or endothelin [ 7 , 8 ]. ...
The present study investigated the effect of a single administration of long-acting follicle simulation hormone (FSH) on testicular blood perfusion as measured by pulsed-wave Doppler ultrasonography, testicular echotexture, and circulating testosterone (T), estradiol (E2), and nitric oxide (NO) in the plasma of rams in the non-breeding season. Twelve Ossimi rams were subjected to either a single administration of long-acting FSH subcutaneously (FSH group; n=6) or the vehicle (control group; n=6). Assessment of testicular hemodynamics at the level of the supratesticular artery was performed just before administration (0 h), and at 4, 24, 48, 72, 96, and 168 h after FSH or the vehicle administrations. Testicular volume (TV), and echotexture of testicular parenchyma including pixel intensity and heterogeneity were derived by the computer analysis software. Concentrations of T, E2, and NO were measured using commercial kits. Results revealed significant decreases (P ˂ 0.05) in the values of Doppler indices (resistive index: RI and pulsatility index: PI), especially at 48 h after administration of FSH (RI: 0.42±0.02, PI: 0.56±0.04) compared to their values in the control group (RI: 0.54±0.03, PI: 0.77±0.04). FSH administration induced significant decreases (P ˂ 0.05) in the pixel intensity of testicular parenchyma. Testicular volume and T concentrations were not significantly changed (P ˃ 0.05). Concentrations of E2 increased significantly (P ˂ 0.05) at 48 h and 72 h after FSH administration. (30.07±5.23 pg/ml, 29.93±1.44 pg/ml, respectively) compared to their values before FSH administration (14.63±1.37 pg/ml). Concentrations of NO increased significantly (P ˂ 0.05) in the FSH group between 4 h to 48 h compared to the values in the control one. In conclusion, a single administration of long-acting FSH enhanced testicular blood perfusion as measured by pulsed Doppler ultrasonography in rams during the non-breeding season. Concurrently, significant increases in the concentrations of E2 and NO were found.
... Alterations of testicular blood flow could be associated with seasonal fluctuation of testosterone, which has been positively correlated to testicular artery diam-eter and blood flow (Pozor 2007). Consequently, higher blood flow could be observed during the breeding season, when testicular volume is higher (Boyd et al. 2006, Sarlós et al. 2013. ...
The present study aimed to investigate the impact of age, season and ejaculation on ram tes-ticular blood flow and echotexture. The survey was conducted biweekly on 7 Chios rams for one year, including breeding and non-breeding periods. The rams were divided into 2 age groups: 3 rams 2-6 years old (mature) and 4 rams 9-13 years old (old). Hemodynamic indices [Pulsatility index (PI), Resistive index (RI), End-diastolic velocity (EDV), testicular artery Diameter (D), Time-averaged maximum velocity (TAVM), Blood flow volume (BFV)] and echotexture parameters [Mean value (MV), Contrast (Con), Gray value distribution (GVD), Run length distribution (RunLD), Long run emphasis (LRunEm), Entropy (Ent), Correlation (Cor), Standard deviation (StD), Gray variance (GV) and Gradient mean value (GMV)] were evaluated in each testis before and after ejaculation. Ejaculation did not affect testes blood flow or echotexture (p>0.05). PI and RI were higher in the breeding period compared to the non-breeding period, for both testes (p<0.001). Left testis GV and Cor before ejaculation were lower (p=0.01) and higher (p=0.03), respectively, in the breeding compared to the non-breeding period. Left testis D (p=0.005) and BFV (p<0.001) were higher in old compared to mature rams after ejaculation. Right testis Con (p=0.03) and Cor (p=0.05) before ejaculation were higher in old rams, whereas right testis Ent after ejaculation was higher in mature rams (p=0.05). In conclusion, testicular blood flow and echotexture are affected by season and ram age, but not by ejaculation.
... Colour Doppler ultrasonography has recently been introduced as a diagnostic tool in veterinary medicine for the evaluation of male reproductive performance in domestic animals (Ginther, 2014). It has been applied as an unconventional diagnostic procedure in male camels (Kutzler et al., 2011), stallions (Pozor, 2007), dogs and rams (Camela et al., 2017). Doppler ultrasonography of the testicular artery was used in veterinary practice to determine the normal function of testes in dogs and stallions (Pozor and McDonnell, 2004;Pozor, 2007). ...
... It has been applied as an unconventional diagnostic procedure in male camels (Kutzler et al., 2011), stallions (Pozor, 2007), dogs and rams (Camela et al., 2017). Doppler ultrasonography of the testicular artery was used in veterinary practice to determine the normal function of testes in dogs and stallions (Pozor and McDonnell, 2004;Pozor, 2007). Seasonal changes in daylight and ambient temperature modulates the haemodynamic parameters of the testicular artery in male Shiba goats (Samir et al., 2018). ...
The aims of the present study were to scan the echogenicity of reproductive organs of bucks during the breeding season. The influence of testosterone on haemodynamic Doppler indices of accessory genital glands of breeding bucks was also examined. Ten clinically healthy, sexually mature, Egyptian Baladi male goats were examined and the testes, tail of epididymis and accessory sex glands imaged using greyscale B-mode, colour Doppler ultrasonography. The spectral Doppler indices (pulsatility index and resistive index) were measured. Blood samples were collected and serum concentrations of testosterone, FSH and LH were determined. The results revealed that the echogenicity of testes, tail of epididymis and accessory genital glands was changed by breeding season. Pulsatility index values of supra-testicular artery, marginal artery, tail of the epididymis, ampulla, vesicular gland, pars disseminata of the prostate and bulbourethral gland were 0.85±0.04, 0.54±0.03, 0.4±0.03, 0.37±0.04, 0.51±0.03, 0.39±0.02 and 0.41±0.04, respectively. The resistive index of the above criteria were 0.51±0.04, 0.37±0.02, 0.3±0.03, 0.27±0.02, 0.31±0.03, 0.32±0.03 and 0.32±0.03, respectively. Serum testosterone concentration was 4.78±0.46 ng/mL. Furthermore, FSH and LH were 3.71±0.43 and 1.8±0.17 mIU/mL, respectively. Interestingly, testosterone clearly deceased the values of the both the pulsatility and resistive indices of the accessory genital glands of breeding bucks. Season modified the echogenicity of testes, epididymis and accessory genital glands. Testosterone regulated the reproductive indices of blood flow of the accessory genital glands of breeding bucks. Thus, this study could serve as a baseline of reference values of Egyptian Baladi male goats during the breeding season to improve reproductive efficiency.
... Varicoceles are especially common in older rams, however, cases of this disease have also been reported in cattle and horses (Koivisto et al., 2002;Pozor, 2007;Foster, 2011). In any case, varicoceles disturb spermatogenesis, being associated with values for semen qualitative and quantitative variables, which inevitably leads to male infertility (Nasr-Esfahani et al., 2009). ...
Improving the methods utilized to facilitate reproduction is associated with a constant need to search for new factors that not only significantly affect reproductive processes, but also create new possibilities when assessing male reproductive potential. Aquaporins (AQPs) belong to a family of small (28−30 kDa) proteins that facilitate the transport of water and other small molecules. There have been 13 AQPs (AQP0-AQP12) discovered in mammals, and these proteins are present in a wide range of cell types. Almost all AQPs, except AQP6 and AQP12 are present in the male reproductive organs and sperm of mammals and birds. Increasing evidence suggests that these proteins are involved in a number of processes responsible for the optimal functioning of the male reproductive system. This review presents the current state of knowledge regarding the abundance and distribution of AQPs in the male reproductive organs and sperm of various livestock and poultry species, including buffalo, cattle, sheep, horses, pigs, turkeys and goose. Furthermore, the possible physiological and pathophysiological significance of AQPs in male reproduction, as well as hormonal regulation of quantities are discussed. It can be concluded from the studies analyzed in this paper that abundance patterns of AQPs may be considered in the future as specific and universal biomarkers of male fertility and infertility in animal husbandry.
... Evaluation of testicular blood flow by Doppler ultrasonography in camelids has been used to determine male fertility (Kutzler et al., 2011). In stallion, Doppler ultrasonography was useful to characterize blood flow in the testicular artery and to determine certain pathological issues conditions as testicular varicocele (Pozor and McDonnell, 2004;and Pozor, 2007). Recently, Samir et al. (2020) demonstrated that the decrease in the RI and PI was associated with significant increases in sperms viability and percentage of normal morphology in bucks. ...
The vascularization of the testis through testicular artery is of great importance to maintain its
normal function. The vascular disruption due to inadequate arterial blood flow of the testis
negatively affects testicular function and semen quality. This study aimed to determine the efficacy
of gonadotropin-releasing hormone (GnRH) administration on testicular vascularity in relation to
testosterone hormonal response. Five clinically healthy adult ossimi rams 18- to 30-months-old
were used. Testicular arteries Doppler examination, blood sampling following GnRH
administration and testosterone hormonal assay were conducted. Both pulsatility index (PI) and
resistance index (RI) significantly decreased in all treated rams starting from 1 hr till 120 hrs after
single GnRH administration, both Doppler indices returned to their pre-treatment values at 144
hours after GnRH administration. Doppler peak systolic velocity (PSV) did not change in response
to GnRH administration. Testosterone hormone concentrations negatively correlated with PI and
RI but not PSV. In conclusion, GnRH would be useful a beneficial therapy for the treatment of
testicular dysfunction in rams by increasing testosterone concentrations and testicular blood flow.
And pulse wave Doppler ultrasonography would be a useful non-invasive clinical tool for
evaluation of the efficacy of novel therapeutic treatments in rams
... The use of Doppler ultrasound in domestic animals is still in development and is being used for monitoring blood flow in different organs and tissues (Ginther & Utt, 2004;Lamb & Boswood, 2005;Medan & Abd El-Aty, 2010). The mechanisms of testicular thermoregulation may influence blood flow provided by the testicular artery, where proper blood supply to the testicle is crucial for spermatogenesis and reproductive function (Pozor, 2007;Setchell, 2006). A better understanding of the relationship between testicular blood flow and the anatomical characteristics of the testicles and scrotum can support a better reproductive assessment. ...
... The decrease in RI coincides with increased blood flow, increased testosterone levels, and higher testicular volume (Strina et al., 2016). In addition, higher levels of testosterone increase the diameter of the vascular lumen, thus reflecting a decrease in vascular resistance (Pozor, 2007). Therefore, this relationship between blood flow and RI can be evidenced in this study through the established negative correlation between the two variables, showing the inverse proportionality between the features. ...
The aim of this study was to compare the biometric testicular characteristics, skin thickness, and hemodynamics of the testicular artery of 12 and 24 months old bulls using Doppler ultrasonography, the study was conducted using 48 indicus-taurus animals. The scrotal circumference and biometry characteristics of the bulls were measured to calculate the testicular volume. Doppler ultrasonography was used to obtain the hemodynamic values of the testicular artery. The skin thickness and volume was lower (p< .01) in the younger bulls (12 months:4.68 ± 0.68 mm; 168.76 ± 47.96 cm3 ) versus 24 months (5.05 ± 0.89; 499.73 ± 129.24 cm3 ) animals (p < .01). During diastole, mean velocity was lower in the 12 months (7.98 ± 3.83) than in the 24 months (11.37 ± 4.15) animals (p < .05). The 12 months animals had higher pulsatility and resistivity indices (0.49 ± 0.02; 0.51 ± 0.20) compared to the 24 months 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 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.
