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Garza-Brenner E, Sánchez-Dávila F, Mauleón-Tolentino K, Zapata-Campos CC, Luna-Palomera C, Hernandez-Melendez J, Gonzalez-Delgado M, Vázquez-Armijo JF. Systematic review of hormonal strategies to improve fertility in rams. Anim Reprod 2024; 21:e20240007. [PMID: 38903866 PMCID: PMC11189135 DOI: 10.1590/1984-3143-ar2024-0007] [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: 01/16/2024] [Accepted: 04/16/2024] [Indexed: 06/22/2024] Open
Abstract
Reviewing the current state of knowledge on reproductive performance and productive traits in rams has many advantages. First, the compilation of this information will serve as a literature resource for scientists conducting research around the world and will contribute to the understanding of the data collected and interpreted by researchers on the different hormonal strategies used to improve reproductive performance in rams. Second, it will allow scientists to identify current knowledge gaps and set future research priorities in ram reproduction. Rams play an important role in the global flock economy, but their reproductive analysis has been limited in the use of hormonal technologies to increase the productivity of sheep flocks. In this review, we cite the most important works on six hormones that, in one way or another, modify the hypothalamus-pituitary-gonadal axis, at different doses, in and out of the reproductive season, breeds, application methods, among other factors. The overall aim is to increase the reproductive efficiency of rams in different scenarios and, in some cases, of other species due to the lack of limited information on rams.
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Affiliation(s)
- Estela Garza-Brenner
- Facultad de Agronomía, Posgrado Conjunto, Universidad Autónoma de Nuevo León, General Escobedo, N.L México
| | - Fernando Sánchez-Dávila
- Facultad de Agronomía, Posgrado Conjunto, Universidad Autónoma de Nuevo León, General Escobedo, N.L México
| | - Keyla Mauleón-Tolentino
- Facultad de Agronomía, Posgrado Conjunto, Universidad Autónoma de Nuevo León, General Escobedo, N.L México
| | - Cecilia Carmela Zapata-Campos
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Tamaulipas, Ciudad Victoria, Tamaulipas, México
| | - Carlos Luna-Palomera
- División Académica de Ciencias Agropecuarias, Universidad Juárez Autónoma de Tabasco, Villahermosa, Tabasco, México
| | | | - Marisol Gonzalez-Delgado
- Centro de Investigación en Producción Agropecuaria, Universidad Autónoma de Nuevo León, Linares, Nuevo León, México
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Shakeel M, Yoon M. Functions of somatic cells for spermatogenesis in
stallions. JOURNAL OF ANIMAL SCIENCE AND TECHNOLOGY 2022; 64:654-670. [PMID: 35969700 PMCID: PMC9353347 DOI: 10.5187/jast.2022.e57] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 06/21/2022] [Accepted: 06/22/2022] [Indexed: 11/20/2022]
Abstract
Spermatogenesis and testis development are highly structured physiological
processes responsible for post-pubertal fertility in stallions. Spermatogenesis
comprises spermatocytogenesis, meiosis, and spermiogenesis. Although germ cell
degeneration is a continuous process, its effects are more pronounced during
spermatocytogenesis and meiosis. The productivity and efficiency of
spermatogenesis are directly linked to pubertal development, degenerated germ
cell populations, aging, nutrition, and season of the year in stallions. The
multiplex interplay of germ cells with somatic cells, endocrine and paracrine
factors, growth factors, and signaling molecules contributes to the regulation
of spermatogenesis. A cell-to-cell communication within the testes of these
factors is a fundamental requirement of normal spermatogenesis. A noteworthy
development has been made recently on discovering the effects of different
somatic cells including Leydig, Sertoli, and peritubular myoid cells on
manipulation the fate of spermatogonial stem cells. In this review, we discuss
the self-renewal, differentiation, and apoptotic roles of somatic cells and the
relationship between somatic and germ cells during normal spermatogenesis. We
also summarize the roles of different growth factors, their
paracrine/endocrine/autocrine pathways, and the different cytokines associated
with spermatogenesis. Furthermore, we highlight important matters for further
studies on the regulation of spermatogenesis. This review presents an insight
into the mechanism of spermatogenesis, and helpful in developing better
understanding of the functions of somatic cells, particularly in stallions and
would offer new research goals for developing curative techniques to address
infertility/subfertility in stallions.
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Affiliation(s)
- Muhammad Shakeel
- Department of Animal Science and
Biotechnology, Kyungpook National University, Sangju 37224,
Korea
- Department of Clinical Studies, Faculty of
Veterinary and Animal Sciences, Pir Mehr Ali Shah, Arid Agriculture
University, Rawalpindi 44000, Pakistan
| | - Minjung Yoon
- Department of Animal Science and
Biotechnology, Kyungpook National University, Sangju 37224,
Korea
- Department of Horse, Companion and Wild
Animal Science, Kyungpook National University, Sangju 37224,
Korea
- Reseach Center for Horse Industry,
Kyungpook National University, Sangju 37224, Korea
- Corresponding author: Minjung Yoon,
Department of Animal Science and Biotechnology, Kyungpook National University,
Sangju 37224, Korea. Tel: +82-54-530-1233, E-mail:
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3
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Abstract
Oxytocin and oxytocin receptors are synthesized in the periphery where paracrine/autocrine actions have been described alongside endocrine actions effected by central release of oxytocin from the posterior pituitary. In the female reproductive system, classical actions of uterine contraction and milk ejection from mammary glands are accompanied by actions in the ovaries where roles in steroidogenesis, follicle recruitment and ovulation have been described. Steroidogenesis, contractile activity, and gamete health are similarly affected by oxytocin in the male reproductive tract. In the cardiovascular system, a local oxytocinergic system appears to play an important cardio-protective role. This role is likely associated with emerging evidence that peripheral oxytocin is an important hormone in the endocrinology of glucose homeostasis due to its actions in adipose, the pancreas, and the largely ignored oxytocinergic systems of the adrenal glands and liver. Gene polymorphisms are shown to be associated with a number of reported traits, not least factors associated with metabolic syndrome.
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Affiliation(s)
- Stephen J Assinder
- Discipline of Physiology, School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, Australia.
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4
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El-Shalofy AS, Hedia MG. Exogenous oxytocin administration improves the testicular blood flow in rams. Andrologia 2021; 53:e14193. [PMID: 34309888 DOI: 10.1111/and.14193] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 07/06/2021] [Accepted: 07/12/2021] [Indexed: 12/20/2022] Open
Abstract
The current research aimed to examine the effects of single-dose oxytocin administration on testicular blood flow measurements peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI) and pulsatility index (PI) and plasma steroid (testosterone and oestradiol-17β) concentrations in rams. In the treated group, eight mature Ossimi rams during the breeding season were injected intravenously (iv) with 20 IU oxytocin, while the other eight male rams were administered normal saline (2 ml) iv as a control group. Venous blood samples and testicular blood flow in the left and right testes were examined immediately before (0) and 5, 30, 60 and 120 min after injections. The control group did not show significant changes in the variables examined (p > .05), except for the EDV (p < .05). In the treated group, the administration of oxytocin led to a significant decrease in RI and PI values starting 5 min after oxytocin administration until 60 min after its application (p < .05). The plasma concentrations of testosterone and oestradiol-17β raised from 5 to 30 min after oxytocin injection (p > .05) and then declined significantly until 120 min (p < .05). In conclusion, oxytocin is a potent testicular vasodilator affecting the testicular vascular tone and steroid concentrations in rams.
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Affiliation(s)
- Amr S El-Shalofy
- Department of Theriogenology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
| | - Mohamed G Hedia
- Department of Theriogenology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
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5
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Jung Y, Yoon M. Oxytocin receptor expression in stallion testes and epididymides. Domest Anim Endocrinol 2021; 74:106562. [PMID: 33038836 DOI: 10.1016/j.domaniend.2020.106562] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 09/07/2020] [Accepted: 09/08/2020] [Indexed: 11/27/2022]
Abstract
Endocrine, paracrine, and autocrine factors orchestrate the development and physiology of the stallion reproductive system. Oxytocin (OXT) is one of the critical endocrine, paracrine, and autocrine factors for the male reproductive system. Previous studies have investigated OXT receptor (OXTR) expression in testes and epididymides, including humans, marmosets, macaques, swine, and sheep. This study aimed to explore (1) OXTR localization in the testes and epididymides and (2) the seasonal modification of OXTR expression in the testes. Adult stallion testis and epididymis samples were prepared using routine castration procedures. Reverse-transcription PCR was performed to detect the presence of OXTR messenger RNA (mRNA) in the testes. Western blot procedure was performed to confirm the cross-reactivity of OXTR antibody to horse OXTR. Immunohistochemistry was performed to detect OXTR protein expression in the testes and epididymides. Oxytocin receptor mRNA was detected in the stallion testes. The OXTR protein band was observed at 55 kDa. Interestingly, the relative intensity of the OXTR protein band varied between nonbreeding and breeding season. The OXTR protein level in the testes collected during the breeding season was higher than that during the nonbreeding season. Oxytocin receptor localization was observed in the cytoplasm of Type A spermatogonia and spermatid. Oxytocin receptor protein expression was also observed in the cytoplasmic area of Leydig cells and the membrane of the seminiferous tubules. The cytoplasm of principal and basal cells in the caput, corpus, and cauda was also immunolabeled with OXTR antibody. In conclusion, based on the expression of OXTR in tissues of testes and epididymides, OXT-OXTR system may be a critical factor for stallion testicular and epididymal function. In addition, according to the seasonal alteration of intensity, the OXT-OXTR system may be associated with seasonal changes in the reproductive system in stallions.
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Affiliation(s)
- Y Jung
- Department of Animal Science and Biotechnology, Kyungpook National University, Sangju 37224, Republic of Korea
| | - M Yoon
- Department of Animal Science and Biotechnology, Kyungpook National University, Sangju 37224, Republic of Korea; Department of Horse, Companion and Wild Animal Science, Kyungpook National University, Sangju 37224, Republic of Korea.
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6
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Stadler B, Whittaker MR, Exintaris B, Middendorff R. Oxytocin in the Male Reproductive Tract; The Therapeutic Potential of Oxytocin-Agonists and-Antagonists. Front Endocrinol (Lausanne) 2020; 11:565731. [PMID: 33193084 PMCID: PMC7642622 DOI: 10.3389/fendo.2020.565731] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 09/07/2020] [Indexed: 12/12/2022] Open
Abstract
In this review, the role of oxytocin and oxytocin-like agents (acting via the oxytocin receptor and belonging to the oxytocin-family) in the male reproductive tract is considered. Previous research (dating back over 60 years) is revised and connected with recently found aspects of the role oxytocin plays in male reproductive health. The local expression of oxytocin and its receptor in the male reproductive tract of different species is summarized. Colocalization and possible crosstalk to other agents and receptors and their resulting effects are discussed. The role of the newly reported oxytocin focused signaling pathways in the male reproductive tract, other than mediating contractility, is critically examined. The structure and effect of the most promising oxytocin-agonists and -antagonists are reviewed for their potential in treating male disorders with origins in the male reproductive tract such as prostate diseases and ejaculatory disorders.
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Affiliation(s)
- Beatrix Stadler
- Institute of Anatomy and Cell Biology, Justus-Liebig-University, Giessen, Germany
| | - Michael R. Whittaker
- Drug Discovery Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Melbourne, VIC, Australia
| | - Betty Exintaris
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Melbourne, VIC, Australia
| | - Ralf Middendorff
- Institute of Anatomy and Cell Biology, Justus-Liebig-University, Giessen, Germany
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Gao DD, Wang LL, Xu JW, Qiu ZE, Zhu YX, Zhang YL, Zhou WL. Cellular mechanism underlying oxytocin-stimulated Cl - secretion in rat cauda epididymal epithelium. Am J Physiol Cell Physiol 2020; 319:C630-C640. [PMID: 32726160 DOI: 10.1152/ajpcell.00397.2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The neurohypophyseal hormone oxytocin (OT) plays critical roles in lactation and parturition, while its function in male reproduction system is largely unknown. This study aims to investigate the effect of OT on regulating transepithelial ion transport in rat cauda epididymal epithelium. With the use of RT-PCR, Western blot, and immunohistochemical analysis, we found that OT receptor (OTR) was expressed and localized at the basal membrane of rat cauda epididymal epithelium. The short-circuit current (Isc) measurement showed that basolateral application of OT to the primary cultured rat cauda epididymal epithelial cells elicited an increase in Isc, which was abrogated by pretreating the epithelial cells with CFTRinh-172, a blocker of cystic fibrosis transmembrane conductance regulator (CFTR). Pretreatment with the prostaglandin H synthase inhibitors indomethacin and piroxicam, or the nonselective antagonists of prostaglandin E2 (PGE2) receptor EP2 or EP4, AH-6809, and AH-23848, significantly attenuated OT-stimulated Isc response. Furthermore, the generation of PGE2 was measured using enzyme-linked immunosorbent assay, demonstrating that OT induced a substantial increase in PGE2 release from primary cultured rat cauda epididymal epithelial cells. In conclusion, activation of OTR by OT triggered PGE2 release, resulting in CFTR-dependent Cl- secretion through paracrine/autocrine pathways in rat cauda epididymal epithelium.
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Affiliation(s)
- Dong-Dong Gao
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Sport and Health Promotion, Scientific Research Center, Guangzhou Sport University, Guangzhou, China
| | - Long-Long Wang
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Jia-Wen Xu
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zhuo-Er Qiu
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yun-Xin Zhu
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yi-Lin Zhang
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Wen-Liang Zhou
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
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8
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Epidermal growth factor, transforming growth factor-alpha, and epidermal growth factor receptor expression and localization in the canine endometrium during the estrous cycle and in bitches with pyometra. Theriogenology 2009; 73:36-47. [PMID: 19853901 DOI: 10.1016/j.theriogenology.2009.08.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2009] [Revised: 07/28/2009] [Accepted: 08/01/2009] [Indexed: 11/20/2022]
Abstract
Gene expression and immunohistochemical localization of epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha), and epidermal growth factor receptor (EGF-R) were compared between the endometrium of bitches (Canis familiaris) with pyometra accompanied by cystic endometrial hyperplasia (CEH) and that of healthy bitches at similar stages of the estrous cycle. In normal bitches, endometrial TGF-alpha mRNA levels were highest at proestrus and gradually decreased as the cycle progressed to anestrus. Epidermal growth factor receptor mRNA levels were not significantly affected by the stage of the estrous cycle. Epidermal growth factor mRNA levels were higher at Day 35 of diestrus than at other stages of the estrous cycle (P<0.05). In bitches with pyometra, endometrial TGF-alpha and EGF-R mRNA levels did not differ significantly from those at diestrus in normal bitches, but EGF mRNA levels were lower than those at Day 35 of diestrus in normal bitches (P<0.05). In normal bitches, positive immunohistochemical staining for TGF-alpha, EGF, and EGF-R was mainly present in the glandular and luminal epithelial cells of the endometrium. In contrast, in bitches with pyometra, immunoreactivity for EGF was clearly present in endometrial stromal cells. Inflammatory cells that had infiltrated the endometrial stroma stained strongly for TGF-alpha and EGF-R. Luminal and glandular epithelial cells also stained positive for EGF-R. In conclusion, expression of TGF-alpha by inflammatory cells and a low level of expression and differential localization of EGF may be involved in aberrant growth of endometrial glands and development of CEH.
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Sendemir E, Herbert Z, Sivukhina E, Zermann DH, Arnold R, Jirikowski GF. Colocalization of Androgen Binding Protein, Oxytocin Receptor, Caveolin 1 and Proliferation Marker p21 in Benign Prostate Hyperplasia. Anat Histol Embryol 2008; 37:325-31. [DOI: 10.1111/j.1439-0264.2008.00848.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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10
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Kida K, Baba E, Torii R, Kawate N, Hatoya S, Wijewardana V, Sugiura K, Sawada T, Tamada H, Inaba T. Lactoferrin expression in the canine uterus during the estrous cycle and with pyometra. Theriogenology 2006; 66:1325-33. [PMID: 16730786 DOI: 10.1016/j.theriogenology.2006.04.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2006] [Accepted: 04/26/2006] [Indexed: 10/24/2022]
Abstract
The expression of lactoferrin, a non-specific antimicrobial defence, in the canine uterus during the normal estrous cycle and in bitches with pyometra was examined. Using polymerase chain reaction analysis, lactoferrin gene transcripts were detected in the endometrium at all stages of the estrous cycle, with the highest levels in estrus. In normal bitches, endometrial lactoferrin mRNA increased from proestrus to estrus (P<0.05). Thereafter, it dramatically decreased from estrus to Day 10 of diestrus (P<0.05), and stayed low at Day 35 of diestrus and anestrus; this was consistent with blood estrogen concentrations. Levels of lactoferrin mRNA were higher in bitches with pyometra than in normal diestrus (P<0.05). With immunohistochemistry, distinct staining of lactoferrin was detected in the luminal and glandular epithelial cells of the endometrium at proestrus and estrus, but little staining was detected at Day 10 of diestrus. At Day 35 of diestrus and anestrus, a partial and weak reaction was present in the same region. In bitches with pyometra, the glandular epithelial cells and many cells in the uterine stroma were strongly stained. Staining cells in the stroma were morphologically similar to neutrophils. No lactoferrin staining was seen in the uterine stromal cells or myometrium in any section. These results suggest that, in the canine uterus, lactoferrin expression is related to the blood concentration of estrogen, and that the dramatic reduction in lactoferrin observed at the early stage of diestrus may impair antimicrobial defense. Also, enhanced expression of lactoferrin mRNA in the endometrium with pyometra may be associated with neutrophil invasion into the uterus to combat the infection.
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Affiliation(s)
- K Kida
- Department of Advanced Pathobiology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka 599-8531, Japan
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Thackare H, Nicholson HD, Whittington K. Oxytocin--its role in male reproduction and new potential therapeutic uses. Hum Reprod Update 2006; 12:437-48. [PMID: 16436468 DOI: 10.1093/humupd/dmk002] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Oxytocin (OT) is traditionally thought of as a "female" neurohypophysis hormone due to its role in parturition and milk ejection. However, OT is recognized as having endocrine and paracrine roles in male reproduction. At ejaculation, a burst of OT is released from the neurohypophysis into the systemic circulation and stimulates contractions of the reproductive tract aiding sperm release. There is conclusive evidence that OT is synthesized within the mammalian testis, epididymis and prostate and the presence of OT receptors (OTRs) through the reproductive tract supports a local action for this peptide. OT has a paracrine role in stimulating contractility of the seminiferous tubules, epididymis and the prostate gland. Interestingly, OT has also been shown to modulate androgen levels in these tissues via stimulation of the conversion of testosterone to dihydrotestostone (DHT) by 5alpha-reductase. The elucidation of OT's role in male reproduction has suggested a number of potential therapeutic uses for this hormone. Exogenous administration of OT has, in some cases, been shown to increase the numbers of ejaculated sperm, possibly by stimulating contractions of the reproductive tract and thus aiding sperm passage. Within the prostate, OT has been shown to affect gland growth both directly and via its interaction with androgen metabolism. Prostate pathologies due to unregulated cell proliferation/growth, such as benign prostatic hyperplasia and cancer, are unfortunately very common and few effective treatments are available. Greater understanding of paracrine growth mediators, such as OT, is likely to provide new mechanisms for treating such pathologies.
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Affiliation(s)
- Hemlata Thackare
- Clinical Science at South Bristol (Obstetrics & Gynaecology), Henry Wellcome Laboratories for Integrated Neuroscience and Endocrinology, University of Bristol, Whitson Street, Bristol, UK
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12
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Ishiguro K, Baba E, Torii R, Tamada H, Kawate N, Hatoya S, Wijewardana V, Kumagai D, Sugiura K, Sawada T, Inaba T. Reduction of mucin-1 gene expression associated with increased Escherichia coli adherence in the canine uterus in the early stage of dioestrus. Vet J 2006; 173:325-32. [PMID: 16413213 DOI: 10.1016/j.tvjl.2005.11.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/15/2005] [Indexed: 11/28/2022]
Abstract
The relation between adherence of Escherichia coli and expression of mucin-1 (Muc1: an integral membrane mucin) mRNA in the endometrium was studied in beagle bitches at different stages of the oestrous cycle and in those with cystic endometrial hyperplasia/pyometra complex (pyometra). The number of E. coli adhering to the endometrium was low at pro-oestrus and oestrus and increased at the early stage (day 10) of dioestrus, corresponding to the implantation period; it declined thereafter. Adhesion of the organisms to endometrial epithelial cells collected at day 10 of dioestrus was inhibited by the addition of D-mannose. When endometrial epithelial cells collected at pro-oestrus were treated with hyaluronidase, an enzyme that digests mucins, the numbers of E. coli adhering to the cells tended to increase. With polymerase chain reaction analysis it was possible to detect Muc1 gene transcripts in the endometrium at all stages of the oestrous cycle, although the level of Muc1 mRNA decreased by day 10 of dioestrus. The levels of Muc1 mRNA in bitches with a clinical stage of pyometra were low and comparable to those at day 10 of dioestrus. The number of E. coli adhering to the endometrium and Muc1 mRNA levels in the endometrium were inversely correlated (r=-0.77, P<0.01). Immunohistochemical analysis showed little staining for Muc1 in the endometrial epithelia at day 10 of dioestrus and in bitches with pyometra. These results suggest that reduction of Muc1 expression is associated with increased E. coli adherence in the canine uterus at the early stage of dioestrus, possibly facilitating the development of pyometra.
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Affiliation(s)
- K Ishiguro
- Department of Advanced Pathobiology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka 599-8531, Japan
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13
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Segarra AB, Arechaga G, Prieto I, Ramirez-Exposito MJ, Martinez-Martos JM, Ramirez M, Alba F, Ruiz-Larrea MB, Ruiz-Sanz JI. Effects of dietary supplementation with fish oil, lard, or coconut oil on oxytocinase activity in the testis of mice. ARCHIVES OF ANDROLOGY 2002; 48:233-6. [PMID: 11964217 DOI: 10.1080/01485010252869333] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Oxytocin (OT), locally synthesized in the testis, is involved in androgen biosynthesis. The use of polyunsaturated fatty acids (e.g., fish oil) in the diet may improve the fertilizing ability in mammals. Cystinyl aminopeptidase (oxytocinase) activity plays a major role regulating the functional status of OT. Sex steroids and the type of the fatty acid used in the diet modify aminopeptidase activities in serum. In the present study, the authors compared the effect of a fish oil supplemented diet with two other diets supplemented with saturated oils (lard and coconut) on oxytocinase activity in the testis of mice. The enzymatic activity was determined fluorometrically using cystinyl-beta-naphthylamide as substrate. The results demonstrated higher levels of oxytocinase activity in mice fed the diet supplemented with fish oil than in those that were fed diets containing lard or coconut oils. The testicular functions in which OT is involved may be attenuated by the use of fish oil in the diet.
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Affiliation(s)
- A B Segarra
- Unit of Physiology, University of Jaén, Spain
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