Testicular Blood Flow and Plasma Concentrations of Testosterone and Total Estrogen in the Stallion after the Administration of Human Chorionic Gonadotropin

Bollwein, Heinrich; Schulze, Johann Joachim; Miyamoto, Akio; Sieme, Harald

doi:10.1262/jrd.20014

Cited by 45 publications

(45 citation statements)

References 26 publications

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“…Measurements were obtained according to previous studies [5, 14]. The angle of insonation used was between 30° and 60° [14, 25]. The ultrasound equipment’s algorithm package was used to calculate the velocities and Doppler indices (Fig 2D).…”

Section: Methodsmentioning

confidence: 99%

Pulse Doppler ultrasound as a tool for the diagnosis of chronic testicular dysfunction in stallions

et al. 2017

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Testicular function is particularly susceptible to vascular insult, resulting in a negative impact on sperm production and quality of the ejaculate. A prompt diagnosis of testicular dysfunction enables implementation of appropriate treatment, hence improving fertility forecasts for stallions. The present research aims to: (1) assess if Doppler ultrasonography is a good tool to diagnose stallions with testicular dysfunction; (2) to study the relationship between Doppler parameters of the testicular artery and those of sperm quality assessed by flow cytometry and (3) to establish cut off values to differentiate fertile stallions from those with pathologies causing testicular dysfunction. A total of 10 stallions (n: 7 healthy stallions and n: 3 sub-fertile stallions) were used in this study. Two ejaculates per stallion were collected and preserved at 5°C in a commercial extender. The semen was evaluated at T0, T24 and T48h by flow cytometry. Integrity and viability of sperm (YoPro®-1/EthD-1), mitochondrial activity (MitoTracker® Deep Red FM) and the DNA fragmentation index (Sperm Chromatin Structure Assay) were assessed. Doppler parameters were measured at three different locations on the testicular artery (Supratesticular artery (SA); Capsular artery (CA) and Intratesticular artery (IA)). The Doppler parameters calculated were: Resistive Index (RI), Pulsatility Index (PI), Peak Systolic Velocity (PSV), End Diastolic Velocity (EDV), Time Average Maximum Velocity (TAMV), Total Arterial Blood Flow (TABF) and TABF rate. The capsular artery was the most reliable location to carry out spectral Doppler assessment, since blood flow parameters of this artery were most closely correlated with sperm quality parameters. Significant differences in all the Doppler parameters studied were observed between fertile and subfertile stallions (p ≤ 0.05). The principal components analysis assay determined that fertile stallions are characterized by high EDV, TAMV, TABF and TABF rate values (high vascular perfusion). In contrast, subfertile stallions tend to present high values of PI and RI (high vascular resistance). The ROC curves revealed that the best Doppler parameters to predict sperm quality in stallions were: Doppler velocities (PSV, EDV and TAMV), the diameter of the capsular artery and TABF parameters (tissue perfusion parameters). Cut off values were established using a Youden´s Index to identify fertile stallions from stallions with testicular dysfunction. Spectral Doppler ultrasound is a good predictive tool for sperm quality since correlations were determined among Doppler parameters and markers of sperm quality. Doppler ultrasonography could be a valuable diagnostic tool for use by clinical practitioners for the diagnosis of stallions with testicular dysfunction and could be a viable alternative to invasive procedures traditionally used for diagnosis of sub-fertility disorders.

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Section: Methodsmentioning

confidence: 99%

Pulse Doppler ultrasound as a tool for the diagnosis of chronic testicular dysfunction in stallions

et al. 2017

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“…The natural peptides luteinizing hormone [98] and human chorionic gonadotrophin (hCG) [99,100] are both known to stimulate androgen production in the Leydig cells of the equine testis, while adrenocorticotrophic hormone (ACTH) promotes a more general steroidogenesis in the adrenal cortex [101,102]. These hormones, their releasing factors and analogues are all prohibited explicitly or implicitly by FEI and IFHA antidoping regulations.…”

Section: Steroidogenic Peptidesmentioning

confidence: 99%

Modern Techniques for the Determination of Anabolic–Androgenic Steroid Doping in the Horse

McKinney

2009

Bioanalysis

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Control of the use of performance-affecting substances in the horse is critical to the integrity of a wide range of equine sports, with major implications for both animal welfare and revenue streams. One class of medications enjoying particular public notoriety is the anabolic-androgenic steroid group, as highlighted by the recent 'Big Brown' affair and Congressional inquiries into the use of steroids in professional sports, including horse racing, in the USA. This review examines the latest developments pertaining to the analytical detection of these substances in equine biological samples and the supporting regulatory environment. Consideration is given to the full variety of sample matrices available, together with modern sample preparative approaches and instrumental techniques. Issues concerning the regulation of endogenous steroids, including thresholds where applicable, are also discussed.

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“…Functional Leydig cells synthesize T following hCG administration. This test has been validated for the bull [9], ram [10], boar [11], stallion [12] and human [13]. However, the profiles of plasma T concentrations after an hCG stimulation test have not been shown to be invariably similar, especially among prepubertal children [14] and bulls with cryptorchidism [15].…”

mentioning

confidence: 99%

Anti-Müllerian Hormone (AMH) Profiles as a Novel Biomarker to Evaluate the Existence of a Functional Cryptorchid Testis in Japanese Black Calves

Kitahara

Ali

Sato

et al. 2012

Journal of Reproduction and Development

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Abstract. Anti-Müllerian hormone (AMH) and testosterone (T) profiles in blood were investigated before and after an hCG stimulation test to assess their sensitivity and specificity for the existence of a functional cryptorchid testis in Japanese Black calves. The hCG (3,000 IU) was administered on Day 0, and peripheral blood was collected on Days 0 (just before hCG injection), 5 and 7 in intact male calves (Intact; n=19), bilateral castrated calves (Castrated; n=17), unilateral cryptorchid calves, which abdominal testis could been extracted (Uni-crypto; n=9). Castration of a descended testis was carried in the Castrated and Uni-Crypto groups on Day -14. The AMH detectability and the optimum cut-off point for T levels using the receiver operating characteristic curve were verified to characterize the cryptorchid testis. AMH values on Day 0 were 21.1 ± 5.1 and 29.0 ± 7.5 ng/ml in the Intact and Uni-crypto groups, respectively (Mean ± SEM). AMH levels were under the detection limit in the Castrated group (i.e., < 0.006 ng/ml). T showed its peak levels on Day 5 in the Intact group (26.8 ± 4.2 ng/ml), while it remained low in the Castrated group (< 0.9 ng/ml) and did not show a significant difference in the Uni-crypto group. The detectable levels for AMH was 0.006 ng/ml, and the optimum cut-off point for T was 0.9 ng/ml; the sensitivity and specificity for evaluation of testicular descent into the scrotum were 1.0 for both the AMH and T levels. The detection rates in the Uni-crypto group using them were 1.0 and 0.57 for AMH on Day 0 and T on Days 5 or 7, respectively. In conclusion, plasma AMH profiles could be used as a novel biomarker to evaluate the existence of a functional cryptorchid testis in Japanese Black calves. Key words: Anti-Müllerian hormone (AMH), Bovine cryptorchidism, hCG stimulation test, Receiver operating characteristic, Testosterone (J. Reprod. Dev. 58: [310][311][312][313][314][315] 2012) C ryptorchidism is the failure of one or both testes to descend into the scrotum during the first trimester of pregnancy [1]. The plausible causes of cryptorchidism include insufficient secretion of insulin-like peptide 3 and/or testosterone (T) [1]. Cryptorchidism is most common in stallions, boars and some breeds of canine, but is rare in most other species [2,3]. The rate of morbidity with cryptorchidism in cattle is 0.2% [4]. The internal body temperature that surrounds the intra-abdominal retained testes associated with cryptorchidism is higher in comparison with that in the scrotum; this compromises spermatogenesis [5].Calves with a cryptorchid testis are commonly detected at castration [3]. If they have unilateral cryptorchid testes, the contralateral descended testes are extracted on the same day, and the cryptorchid testis is then usually looked for by laparotomy on another day. However, exteriorization of an abdominal testis is difficult [6].Fattening bulls with cryptorchidism in the later growing stages usually result in bulls with a stout body type that exhibit masculine characteristics in the ne...

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Testicular Blood Flow and Plasma Concentrations of Testosterone and Total Estrogen in the Stallion after the Administration of Human Chorionic Gonadotropin

Cited by 45 publications

References 26 publications

Pulse Doppler ultrasound as a tool for the diagnosis of chronic testicular dysfunction in stallions

Pulse Doppler ultrasound as a tool for the diagnosis of chronic testicular dysfunction in stallions

Modern Techniques for the Determination of Anabolic–Androgenic Steroid Doping in the Horse

Anti-Müllerian Hormone (AMH) Profiles as a Novel Biomarker to Evaluate the Existence of a Functional Cryptorchid Testis in Japanese Black Calves

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