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Santacruz-Márquez R, Neff AM, Mourikes VE, Fletcher EJ, Flaws JA. The effects of inhaled pollutants on reproduction in marginalized communities: a contemporary review. Inhal Toxicol 2024; 36:286-303. [PMID: 37075037 PMCID: PMC10584991 DOI: 10.1080/08958378.2023.2197941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 03/25/2023] [Indexed: 04/20/2023]
Abstract
Important differences in health that are closely linked with social disadvantage exist within and between countries. According to the World Health Organization, life expectancy and good health continue to increase in many parts of the world, but fail to improve in other parts of the world, indicating that differences in life expectancy and health arise due to the circumstances in which people grow, live, work, and age, and the systems put in place to deal with illness. Marginalized communities experience higher rates of certain diseases and more deaths compared to the general population, indicating a profound disparity in health status. Although several factors place marginalized communities at high risk for poor health outcomes, one important factor is exposure to air pollutants. Marginalized communities and minorities are exposed to higher levels of air pollutants than the majority population. Interestingly, a link exists between air pollutant exposure and adverse reproductive outcomes, suggesting that marginalized communities may have increased reproductive disorders due to increased exposure to air pollutants compared to the general population. This review summarizes different studies showing that marginalized communities have higher exposure to air pollutants, the types of air pollutants present in our environment, and the associations between air pollution and adverse reproductive outcomes, focusing on marginalized communities.
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Affiliation(s)
| | - Alison M. Neff
- Department of Comparative Biosciences, University of Illinois Urbana-Champaign
| | | | - Endia J. Fletcher
- Department of Comparative Biosciences, University of Illinois Urbana-Champaign
| | - Jodi A. Flaws
- Department of Comparative Biosciences, University of Illinois Urbana-Champaign
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Budiyanto A, Hartanto S, Widayanti R, Kurnianto H, Wardi W, Haryanto B, Munir IM, Ibrahim A, Ludfiani DD. Impact of melatonin administration on sperm quality, steroid hormone levels, and testicular blood flow parameters in small ruminants: A meta-analysis. Vet World 2024; 17:911-921. [PMID: 38798291 PMCID: PMC11111706 DOI: 10.14202/vetworld.2024.911-921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 04/04/2024] [Indexed: 05/29/2024] Open
Abstract
Background and Aim The impact of exogenous melatonin on the sperm quality of small ruminants is controversial. Therefore, this study aimed to synthesize previous findings on the influence of melatonin injection on sperm quality, steroid hormones, and testicular blood flow in small ruminants. Materials and Methods Thirty studies were analyzed by computing the raw mean difference (RMD) as the effect size between the control and melatonin treatment groups, using the inverse of the variance for the random-effect model of the method of moments by DerSimonian and Laird. We assessed heterogeneity among studies using Q test. I2 statistic was used to classify the observed heterogeneity. We used Egger's regression method to indicate publication bias. Results Melatonin injection (p < 0.05) affected sperm concentration (RMD = 0.42 × 109/mL), morphology (RMD = 2.82%), viability (RMD = 2.83%), acrosome integrity (RMD = 4.26%), and DNA integrity (RMD = 1.09%). Total motility (RMD = 5.62%), progressive motility (RMD = 7.90%), acrosome integrity (RMD = 8.68%), and DNA integrity (RMD = 2.01%) of post-thawed semen in the melatonin-treated group were also increased (p < 0.05). Similarly, treatment with melatonin (p < 0.05) enhanced total motility (RMD = 5.78%), progressive motility (RMD = 5.28%), curvilinear velocity (RMD = 4.09 μm/s), straight-line velocity (RMD = 5.61 μm/s), and average path velocity (RMD = 4.94 μm/s). Testosterone (RMD = 1.02 ng/mL) and estradiol 17-ß levels (RMD = 0.84 pg/mL) were elevated (p < 0.05) in the melatonin-injected group. Melatonin implantation ameliorated testicular blood flow, as indicated by a significant reduction (p < 0.05) in the resistive index (RMD = 0.11) and pulsatility index (RMD = -0.15). Conclusion Melatonin administration can increase the reproductive performance of small male ruminants.
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Affiliation(s)
- Agung Budiyanto
- Department of Reproduction, Obstetrics, and Gynecology, Faculty of Veterinary Medicine, Gadjah Mada University, Yogyakarta, Indonesia
| | - Slamet Hartanto
- Research Center for Animal Husbandry, National Research and Innovation Agency, Bogor, Indonesia
| | - Rini Widayanti
- Department of Biochemistry and Molecular Biology, Faculty of Veterinary Medicine, Gadjah Mada University, Yogyakarta, Indonesia
| | - Heri Kurnianto
- Research Center for Veterinary Science, National Research and Innovation Agency, Bogor, Indonesia
| | - Wardi Wardi
- Research Center for Animal Husbandry, National Research and Innovation Agency, Bogor, Indonesia
| | - Bambang Haryanto
- Research Center for Sustainable Production System and Life Cycle Assessment, National Research and Innovation Agency, Banten, Indonesia
| | - Ivan Mambaul Munir
- Research Center for Veterinary Science, National Research and Innovation Agency, Bogor, Indonesia
| | - Alek Ibrahim
- Research Center for Animal Husbandry, National Research and Innovation Agency, Bogor, Indonesia
| | - Dini Dwi Ludfiani
- Research Center for Sustainable Production System and Life Cycle Assessment, National Research and Innovation Agency, Banten, Indonesia
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El-Sherbiny HR, El-Shalofy AS, Samir H. Association between body condition score, testicular haemodynamics and echogenicity, nitric oxide levels, and total antioxidant capacity in rams. Ir Vet J 2023; 76:7. [PMID: 36895047 PMCID: PMC9996858 DOI: 10.1186/s13620-023-00235-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 02/24/2023] [Indexed: 03/11/2023] Open
Abstract
Higher body fatness adversely affects metabolic and hormonal homeostasis. The present work aimed to evaluate the association between body condition score (BCS) and haemodynamic pattern and echogenic appearence of the testes as well as nitric oxide (NO) levels and total antioxidant capacity (TAC). For that, fifteen Ossimi rams were blocked according to their BCS into a lower BCS group (L-BCS:2-2.5; n = 5), medium BCS group (M-BCS:3-3.5; n = 5), and higher BCS group (H-BCS:4-4.5; n = 5). Rams were examined for testicular haemodynamics (TH; Doppler ultrasonography), testicular echotexture (TE; B-mode image software analysis), and serum levels of NO and TAC (colorimetric). Results are presented as means ± standard error of the mean. There was a significant (P < 0.05) difference in the resistive index and pulsatility index means among the groups under experimentation, being the least in the L-BCS group (0.43 ± 0.02 and 0.57 ± 0.04, respectively) compared to the M-BCS (0.53 ± 0.03 and 0.77 ± 0.03, respectively) and H-BCS rams (0.57 ± 0.01 and 0.86 ± 0.03, respectively). Among blood flow velocity measurements [peak systolic, end-diastolic (EDV), and time-average maximum], only EDV showed significant (P < 0.05) higher values in the L-BCS group (17.06 ± 1.03 cm/s) compared to M-BCS (12.58 ± 0.67 cm/s) and H-BCS (12.51 ± 0.61 cm/s) groups. Regarding the TE results, there were no significant differences among the examined groups. There were significant differences (P < 0.01) in the concentrations of TAC and NO among the groups under experimentation, in which the L-BCS rams had the highest levels of TAC and NO in their sera (0.90 ± 0.05 mM/L and 62.06 ± 2.72 μM/L, respectively) than the M-BCS (0.058 ± 0.05 mM/L and 47.89 ± 1.49 μM/L, respectively) and H-BCS rams (0.45 ± 0.03 mM/L and 49.93 ± 3.63 μM/L, respectively). In conclusion, body condition score is associated with both testicular hemodynamic and the antioxidant capacity in rams.
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Affiliation(s)
- Hossam R El-Sherbiny
- Theriogenology Department, Faculty of Veterinary Medicine, Cairo University, Giza, 12211, Egypt.
| | - Amr S El-Shalofy
- Theriogenology Department, Faculty of Veterinary Medicine, Cairo University, Giza, 12211, Egypt
| | - Haney Samir
- Theriogenology Department, Faculty of Veterinary Medicine, Cairo University, Giza, 12211, Egypt
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Supplemental dietary curcumin improves testicular hemodynamics, testosterone levels, and semen quality in Baladi bucks in the non-breeding season. Theriogenology 2022; 188:100-107. [DOI: 10.1016/j.theriogenology.2022.05.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 12/19/2022]
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Exogenous gonadotropin-releasing hormone counteracts the adverse effect of scrotal insulation on testicular functions in bucks. Sci Rep 2022; 12:7869. [PMID: 35551262 PMCID: PMC9098548 DOI: 10.1038/s41598-022-11884-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 04/29/2022] [Indexed: 11/08/2022] Open
Abstract
This study determined the effects of scrotal insulation on testicular functions in bucks and evaluated the impact of exogenous gonadotropin-releasing hormone (GnRH) administration before scrotal insulation on sperm production and testicular vascular dynamics. Twelve bucks were randomly divided into three groups: scrotal-insulated animals without GnRH treatment (INS), scrotal-insulated animals treated previously with GnRH (GnRH + INS), and animals without insulation as controls (CON). Doppler ultrasonography was used to evaluate testicular vascular changes, and semen samples were collected to assess seminal parameters. Testicular samples were collected from slaughtered bucks at the end of the experiment for histological investigations and immunohistochemical analysis for caspase 3 (apoptotic marker), and a vascular endothelial growth factor (VEGF; hypoxic marker) evaluation. Sperm motility drastically decreased (33%) in the INS group on day 8 compared with those in the GnRH + INS and CON groups (58% and 85%, respectively). Testicular blood flow significantly decreased for 3 and 2 weeks in the INS and GnRH + INS groups, respectively. The pulsatility index (PI) reached pretreatment values at 5 and 4 weeks after insulation in the INS and GnRH + INS groups, respectively. The resistance index (RI) values increased in both insulated groups for the first 2 weeks and decreased to control values 4 weeks after insulation. However, the maximum velocity (VP) started to increase reaching pretreatment values by the 5th and 3rd weeks after insulation in the INS and GnRH + INS groups, respectively. Histological investigations showed a marked reduction in lipid inclusions in Sertoli cells in the GnRH + INS group compared with those in the INS group. The distributions of both caspase 3 and VEGF decreased in the GnRH + INS group compared with those in the INS group. This study showed that the administration of a single dose of GnRH delayed the negative effects of scrotal insulation on different seminal traits and revealed the pivotal role of GnRH in compensating testicular insulation in bucks.
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El-Shalofy A, Hedia M, Kastelic J. Melatonin improves testicular haemodynamics, echotexture and testosterone production in Ossimi rams during the breeding season. Reprod Domest Anim 2021; 56:1456-1463. [PMID: 34459033 DOI: 10.1111/rda.14010] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Accepted: 08/27/2021] [Indexed: 12/13/2022]
Abstract
The objective was to determine effects of a single parenteral dose of melatonin on testicular blood flow indices, testicular echogenicity and plasma testosterone concentrations in rams during the physiological breeding season. We hypothesized that melatonin enhances testicular blood flow, echogenicity and plasma testosterone concentrations during the breeding season in rams. During the breeding season, 12 sexually mature Ossimi rams were randomly allocated to either a melatonin group (n = 8) that received 18 mg of melatonin in 1 ml of corn oil (injected SC) or a control group (n = 4) that received 1 ml corn oil only. Blood collection and ultrasonographic assessment of the testes and supratesticular arteries were conducted immediately before treatment (W0) and once weekly for 6 weeks after melatonin injection (W1-W6). Mean plasma testosterone concentrations were greater (p < .05; at least 1 ng/ml) in the melatonin-treated group compared to the control group from W4 to W6 after treatment. A decrease (p < .05) in both resistive index (RI) and pulsatility index (PI) began 1 week after melatonin injection (W1) and persisted until the end of the experiment, with mean RI and PI values in the melatonin group lower (p < .05) than those in the control group on W3 and W4. Furthermore, plasma testosterone concentrations in melatonin-treated rams were inversely correlated to both RI and PI (r = -.7 and -.6, respectively, p < .01). Testicular echogenicity decreased (p < .05) 1 week after melatonin injection (W1) and remained lower (p < .05) in the melatonin-treated group compared to the control group until the end of the study (W6). In conclusion, melatonin administration significantly altered testicular blood flow and echogenicity and increased plasma testosterone concentrations in Ossimi rams during the breeding season.
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Affiliation(s)
- Amr El-Shalofy
- Department of Theriogenology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
| | - Mohamed Hedia
- Department of Theriogenology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
| | - John Kastelic
- Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
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Guo Y, Yang Y, Wang B, Liu C, Li M, Wang X. Morphological and scanning electron microscopic study of the gonadal arterioles in the Tibetan sheep. Anat Histol Embryol 2021; 50:694-700. [PMID: 33878221 DOI: 10.1111/ahe.12671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 12/18/2020] [Accepted: 03/06/2021] [Indexed: 11/30/2022]
Abstract
This research aimed at revealing the structural features of Tibetan sheep's testicular and ovarian vasculature and providing theoretical basis for Tibetan sheep's physiological adaptability in plateau and low-oxygen environments. Through scanning electron microscopy, corrosion casts of the feature of the gonad arterioles were observed and analysed. The results of this study found that centrifugal arteries, centrifugal and centripetal arterioles were distributed in a 'dendritic' fashion in the testis lobule, the ovarian arteries and arterioles, which had a spiral shape. Testicular Tibetan Sheep knot-like artery had a denser spiral structure, and there were more branches in the microarteries. On the testis lobule and arteriole of caput epididymidis, the arteriole surface shows the 'fusiform' indentation to be more shallower. The ovarian artery had a higher degree of helix; its surface was distributed like a 'bark-like' indentation; and the ring was narrower and denser. Nevertheless, the arteriole network had a high concentration and a wide number of branches, as that of the ovarian arteriole network which had more end branches, the surface of the arterioles of ovaries and testicles was scarred and denser. The studies indicate that the structural features of testicular lobule, epididymal arterioles and ovarian arterioles are more conducive to increase the oxygen supply to the gonads tissue and controlling blood flow velocity and metabolism to respond to high altitudes and low-oxygen environments.
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Affiliation(s)
- Yajun Guo
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Yanan Yang
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Biao Wang
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Chengze Liu
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Mingna Li
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Xinrong Wang
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
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Acute mild heat stress alters gene expression in testes and reduces sperm quality in mice. Theriogenology 2020; 158:375-381. [DOI: 10.1016/j.theriogenology.2020.10.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 10/01/2020] [Accepted: 10/02/2020] [Indexed: 12/30/2022]
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9
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Lemos H, Dorado J, Hidalgo M, Gaivão I, Martins-Bessa A. Assessment of Dog Testis Perfusion by Colour and Pulsed-Doppler Ultrasonography and Correlation With Sperm Oxidative DNA Damage. Top Companion Anim Med 2020; 41:100452. [PMID: 32823153 DOI: 10.1016/j.tcam.2020.100452] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Revised: 05/22/2020] [Accepted: 05/31/2020] [Indexed: 02/07/2023]
Abstract
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.
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Affiliation(s)
- Helena Lemos
- University of Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal
| | - Jesus Dorado
- Veterinary Reproduction Group, Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, University of Cordoba, Cordoba, Spain
| | - Manuel Hidalgo
- Veterinary Reproduction Group, Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, University of Cordoba, Cordoba, Spain
| | - Isabel Gaivão
- Department of Genetics and Biotechnology, School of Life Sciences and Environment, UTAD, Vila Real, Portugal; Animal and Veterinary Research Centre (CECAV), UTAD, Quinta de Prados, Vila Real, Portugal
| | - Ana Martins-Bessa
- Animal and Veterinary Research Centre (CECAV), UTAD, Quinta de Prados, Vila Real, Portugal; Department of Veterinary Sciences, School of Agrarian and Veterinary Sciences, UTAD, Vila Real, Portugal;.
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Samir H, Nyametease P, Elbadawy M, Nagaoka K, Sasaki K, Watanabe G. Administration of melatonin improves testicular blood flow, circulating hormones, and semen quality in Shiba goats. Theriogenology 2020; 146:111-119. [PMID: 32078960 DOI: 10.1016/j.theriogenology.2020.01.053] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 01/04/2020] [Accepted: 01/25/2020] [Indexed: 12/28/2022]
Abstract
Despite the role of melatonin in the regulation of the sleep-wake cycle and seasonal-reproduction, the present study investigated, for the first time, the potential role of melatonin on testicular blood flow (TBF) in goats. Twelve sexually mature male Shiba goats were exposed to a single s.c. injection of either melatonin suspended in one ml of corn oil (melatonin group; 36 mg/goat; n = 5) or one ml of corn oil (control group; n = 7). Monitoring the changes in TBF was done one week before (W-1), at the time of injection (W0), and once a week for 8 weeks after injection using color-pulsed Doppler ultrasonography. Concentrations of FSH, LH, inhibin, testosterone (T), estradiol (E2), and insulin-like growth factor-1 (IGF-1) in plasma were determined by radioimmunoassay. Melatonin and nitric oxide (NO) concentrations were measured using enzyme immunoassay kits. Moreover, semen collection and evaluation of some sperm parameters were performed once a week. Results revealed decreases (P < 0.05) in the Doppler indices (resistive index, pulsatility index) of the testicular arteries from W2 till W6 in the melatonin group. FSH, LH, and inhibin concentrations did not change between the two groups, while T, E2, IGF-1, NO, and melatonin concentrations increased (P < 0.05) in the melatonin group compared to the control. Estradiol and NO concentrations increased (P < 0.05), coinciding with decreases in the values of Doppler indices. Notable (P < 0.05) improvements in most parameters of semen quality were seen in the melatonin group. In conclusion, melatonin induced a stimulatory effect on TBF in Shiba goats and possibly, it could be a potential to improve male goats fertility.
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Affiliation(s)
- Haney Samir
- Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 183-8509, Japan; Department of Theriogenology, Faculty of Veterinary Medicine, Cairo University, Giza, 12211, Egypt.
| | - Paul Nyametease
- Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 183-8509, Japan; Department of Animal Science, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
| | - Mohamed Elbadawy
- Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 183-8509, Japan; Department of Pharmacology, Faculty of Veterinary Medicine, Benha University, Moshtohor, Toukh, Elqaliobiya, 13736, Egypt
| | - Kentaro Nagaoka
- Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 183-8509, Japan
| | - Kazuaki Sasaki
- Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 183-8509, Japan
| | - Gen Watanabe
- Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 183-8509, Japan.
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Rizzoto G, Ferreira JCP, Mogollón Garcia HD, Teixeira-Neto FJ, Bardella LC, Martins CL, Silva JRB, Thundathil JC, Kastelic JP. Short-term testicular warming under anesthesia causes similar increases in testicular blood flow in Bos taurus versus Bos indicus bulls, but no apparent hypoxia. Theriogenology 2020; 145:94-99. [PMID: 32007637 DOI: 10.1016/j.theriogenology.2020.01.045] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 01/17/2020] [Accepted: 01/21/2020] [Indexed: 01/14/2023]
Abstract
Bull testes must be 4-5 °C below body temperature, with testicular warming more likely to cause poor-quality sperm in Bos taurus (European/British) versus Bos indicus (Indian/zebu) bulls. Despite a long-standing dogma that testicular hyperthermia causes hypoxia, we reported that increasing testicular temperature in bulls and rams enhanced testicular blood flow and O2 delivery/uptake, without hypoxia. Our objective was to determine effects of short-term testicular hyperthermia on testicular blood flow, O2 delivery and uptake and evidence of testicular hypoxia in pubertal Angus (B. taurus) and Nelore (B. indicus) bulls (nine per breed) under isoflurane anesthesia. As testes were warmed from 34 to 40 °C, there were increases (P < 0.0001, but no breed effects) in testicular blood flow (mean ± SEM, 9.59 ± 0.10 vs 17.67 ± 0.29 mL/min/100 g, respectively), O2 delivery (1.79 ± 0.06 vs 3.44 ± 0.11 mL O2/min/100 g) and O2 consumption (0.69 ± 0.07 vs 1.25 ± 0.54 mL O2/min/100 g), but no indications of testicular hypoxia. Hypotheses that: 1) both breeds increase testicular blood flow in response to testicular warming; and 2) neither breed has testicular hypoxia, were supported; however, the hypothesis that the relative increase in blood flow is greater in Angus versus Nelore was not supported. Although these were short-term increases in testicular temperature in anesthetized bulls, results did not support the long-standing dogma that increased testicular temperature does not increase testicular blood flow and an ensuing hypoxia is responsible for decreases in motile, morphologically normal and fertile sperm.
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Affiliation(s)
- G Rizzoto
- Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
| | - J C P Ferreira
- Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science, São Paulo State University (UNESP), Botucatu, SP, Brazil.
| | - H D Mogollón Garcia
- Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - F J Teixeira-Neto
- Department of Veterinary Surgery and Anesthesiology, School of Veterinary Medicine and Animal Science, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - L C Bardella
- School of Medicine, Experimental Research Unit, Botucatu, SP, Brazil
| | - C L Martins
- Department of Animal Breeding and Nutrition, School of Veterinary Medicine and Animal Science São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - J R B Silva
- Department of Veterinary Surgery and Anesthesiology, School of Veterinary Medicine and Animal Science, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - J C Thundathil
- Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
| | - J P Kastelic
- Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
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Rizzoto G, Kastelic JP. A new paradigm regarding testicular thermoregulation in ruminants? Theriogenology 2019; 147:166-175. [PMID: 31785861 DOI: 10.1016/j.theriogenology.2019.11.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 11/16/2019] [Accepted: 11/17/2019] [Indexed: 02/05/2023]
Abstract
Increased testicular temperature reduces percentages of morphologically normal and motile sperm and fertility. Specific sperm defects appear at consistent intervals after testicular hyperthermia, with degree and duration of changes related to intensity and duration of the thermal insult. Regarding pathogenesis of testicular hyperthermia on sperm quality and fertility, there is a long-standing paradigm that: 1) testes operate near hypoxia; 2) blood flow to the testes does not increase in response to increased testicular temperature; and 3) an ensuing hypoxia is the underlying cause of heat-induced changes in sperm morphology and function. There are very limited experimental data to support this paradigm, but we have data that refute it. In 2 × 3 factorial studies, mice and rams were exposed to two testicular temperatures (normal and increased) and three concentrations of O2 in inspired air (hyperoxia, normoxia and hypoxia). As expected, increased testicular temperature had deleterious effects on sperm motility and morphology; however, hyperoxia did not prevent these changes nor did hypoxia replicate them. In two follow-up experiments, anesthetized rams were sequentially exposed to: 1) three O2 concentrations (100, 21 and 13% O2); or 2) three testicular temperatures (33, 37 and 40 °C). As O2, decreased, testis maintained O2 delivery and uptake by increasing testicular blood flow and O2 extraction, with no indication of anaerobic metabolism. Furthermore, as testicular temperature increased, testicular metabolic rate nearly doubled, but increased blood flow and O2 extraction prevented testicular hypoxia and anaerobic metabolism. In conclusion, our data, in combination with other reports, challenged the paradigm that testicular hyperthermia fails to increase testicular blood flow and the ensuing hypoxia disrupts spermatogenesis.
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Affiliation(s)
- G Rizzoto
- Faculty of Veterinary Medicine, Department of Production Animal Health, University of Calgary, 3280 Hospital Drive, Calgary, AB, Canada, T2N 4Z6
| | - J P Kastelic
- Faculty of Veterinary Medicine, Department of Production Animal Health, University of Calgary, 3280 Hospital Drive, Calgary, AB, Canada, T2N 4Z6.
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