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Loebenstein M, Thorup J, Cortes D, Clasen-Linde E, Hutson JM, Li R. Cryptorchidism, gonocyte development, and the risks of germ cell malignancy and infertility: A systematic review. J Pediatr Surg 2020; 55:1201-1210. [PMID: 31327540 DOI: 10.1016/j.jpedsurg.2019.06.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 06/18/2019] [Accepted: 06/28/2019] [Indexed: 11/30/2022]
Abstract
BACKGROUND/AIM Cryptorchidism, or undescended testis (UDT) occurs in 1%-4% of newborn males and leads to a risk of infertility and testicular malignancy. Recent research suggests that infertility and malignancy in UDT may be caused by abnormal development of the neonatal germ cells, or gonocytes, which normally transform into spermatogonial stem cells (SSC) or undergo apoptosis during minipuberty at 2-6 months in humans (2-6 days in mice). We aimed to identify the current knowledge on how UDT is linked to infertility and malignancy. METHODS Here we review the literature from 1995 to the present to assess the possible causes of infertility and malignancy in UDT, from both human studies and animal models. RESULTS Both the morphological steps and many of the genes involved in germ cell development are now characterized, but the factors involved in gonocyte transformation and apoptosis in both normal and cryptorchid testes are not fully identified. During minipuberty there is evidence for the hypothalamic-pituitary axis stimulating gonocyte transformation, but without known direct control by LH and androgen, although FSH may have a role. An arrested gonocyte maybe the origin of later malignancy at least in syndromic cryptorchid testes in humans, which is consistent with the recent finding that gonocytes are normally absent in a rodent model of congenital cryptorchidism, where malignancy has not been reported. CONCLUSION The results of this review strengthen the view that malignancy and infertility in men with previous UDT may be caused by abnormalities in germ cell development during minipuberty. TYPE OF STUDY Systematic review (secondary, filtered) LEVEL OF EVIDENCE: Level I.
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Affiliation(s)
- Moshe Loebenstein
- Douglas Stephens Surgical Research Group, Murdoch Children's Research Institute, Melbourne, Australia; Department of Paediatrics, University of Melbourne, Australia
| | - Jorgen Thorup
- Department of Paediatric Surgery, Rigshospitalet, Copenhagen, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Dina Cortes
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Section of Endocrinology, Department of Pediatrics, Copenhagen University Hospital Hvidovre, Denmark
| | - Erik Clasen-Linde
- Department of Pathology, Copenhagen University Hospital Rigshospitalet, Denmark
| | - John M Hutson
- Douglas Stephens Surgical Research Group, Murdoch Children's Research Institute, Melbourne, Australia; Department of Paediatrics, University of Melbourne, Australia; Department of Urology, The Royal Children's Hospital, Melbourne, Australia
| | - Ruili Li
- Douglas Stephens Surgical Research Group, Murdoch Children's Research Institute, Melbourne, Australia; Department of Paediatrics, University of Melbourne, Australia.
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Loebenstein M, Hutson J, Li R. Gonocyte transformation in a congenitally cryptorchid rat is normal and may be similar to the situation reported in human acquired cryptorchidism. J Pediatr Surg 2018; 53:1770-1775. [PMID: 29429771 DOI: 10.1016/j.jpedsurg.2017.12.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 12/06/2017] [Accepted: 12/29/2017] [Indexed: 11/18/2022]
Abstract
BACKGROUND In congenital undescended testis (UDT) in humans, thermal insult damages early germ cell development during mini-puberty (3-6months) causing increased risk of both cancer and infertility. In rodents however, UDT causes infertility but not cancer. In the TS rat with congenital UDT we hypothesized that early germ cell development would be normal as UDT only becomes manifest at 3-4weeks (and the germ cells only become sensitive to thermal injury) after minipuberty is complete at 1week. METHODS Normal testis and potential UDT from unilateral cryptorchid TS rats were collected at week 1 and 4 and processed into paraffin sections labeled for Sertoli cells (AMH), early germ cells (MVH) and spermatogonial stem cells (PLZF). Confocal microscopic images and Fiji Image J were used to count cells in testicular tubules with paired T-test statistical analysis. RESULTS Total germ cells/tubule, basement membrane-bound germ cells/tubule, and Sertoli cells/tubule were unchanged between normally descending and future UDT at 1-4weeks old (P>0.05) Total germ cells/tubule and spermatogonial stem cells/tubule increased dramatically between weeks 1 and 4. CONCLUSION Rat gonocyte transformation is normal in both normally descending and future UDT. This suggests that congenitally cryptorchid rats may not develop testicular cancer because gonocytes (the putative origin of malignant degeneration) normally transform into spermatogonial stem cells before UDT occurs and the risk of thermal injury develops. This suggests the TS rat may be a good model for acquired UDT in human where the abnormal testicular position develops after gonocyte transformation is completed in the first year.
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Affiliation(s)
- Moshe Loebenstein
- FD Stephens Surgical Research Group, Murdoch Children's Research Institute, Parkville, Victoria, 3052, Australia; Department of Paediatrics, University of Melbourne, Parkville, Victoria, 3052, Australia
| | - John Hutson
- FD Stephens Surgical Research Group, Murdoch Children's Research Institute, Parkville, Victoria, 3052, Australia; Department of Urology, Royal Children's Hospital, Parkville, Victoria, 3052, Australia; Department of Paediatrics, University of Melbourne, Parkville, Victoria, 3052, Australia
| | - Ruili Li
- FD Stephens Surgical Research Group, Murdoch Children's Research Institute, Parkville, Victoria, 3052, Australia; Department of Paediatrics, University of Melbourne, Parkville, Victoria, 3052, Australia.
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Abstract
Testicular descent occurs in two morphologically distinct phases, each under different hormonal control from the testis itself. The first phase occurs between 8 and 15 weeks when insulin-like hormone 3 (Insl3) from the Leydig cells stimulates the gubernaculum to swell, thereby anchoring the testis near the future inguinal canal as the foetus grows. Testosterone causes regression of the cranial suspensory ligament to augment the transabdominal phase. The second, or inguinoscrotal phase, occurs between 25 and 35 weeks, when the gubernaculum bulges out of the external ring and migrates to the scrotum, all under control of testosterone. However, androgen acts mostly indirectly via the genitofemoral nerve (GFN), which produces calcitonin gene-related peptide (CGRP) to control the direction of migration. In animal models the androgen receptors are in the inguinoscrotal fat pad, which probably produces a neurotrophin to masculinise the GFN sensory fibres that regulate gubernacular migration. There is little direct evidence that this same process occurs in humans, but CGRP can regulate closure of the processus vaginalis in inguinal hernia, confirming that the GFN probably mediates human testicular descent by a similar mechanism as seen in rodent models. Despite increased understanding about normal testicular descent, the common causes of cryptorchidism remain elusive.
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Hutson JM, Southwell BR, Li R, Lie G, Ismail K, Harisis G, Chen N. The regulation of testicular descent and the effects of cryptorchidism. Endocr Rev 2013; 34:725-52. [PMID: 23666148 DOI: 10.1210/er.2012-1089] [Citation(s) in RCA: 118] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The first half of this review examines the boundary between endocrinology and embryonic development, with the aim of highlighting the way hormones and signaling systems regulate the complex morphological changes to enable the intra-abdominal fetal testes to reach the scrotum. The genitoinguinal ligament, or gubernaculum, first enlarges to hold the testis near the groin, and then it develops limb-bud-like properties and migrates across the pubic region to reach the scrotum. Recent advances show key roles for insulin-like hormone 3 in the first step, with androgen and the genitofemoral nerve involved in the second step. The mammary line may also be involved in initiating the migration. The key events in early postnatal germ cell development are then reviewed because there is mounting evidence for this to be crucial in preventing infertility and malignancy later in life. We review the recent advances in what is known about the etiology of cryptorchidism and summarize the syndromes where a specific molecular cause has been found. Finally, we cover the recent literature on timing of surgery, the issues around acquired cryptorchidism, and the limited role of hormone therapy. We conclude with some observations about the differences between animal models and baby boys with cryptorchidism.
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Affiliation(s)
- John M Hutson
- Urology Department, Royal Children's Hospital, Parkville 3052, Victoria, Australia.
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Lie G, Hutson JM. The role of cremaster muscle in testicular descent in humans and animal models. Pediatr Surg Int 2011; 27:1255-65. [PMID: 22038274 DOI: 10.1007/s00383-011-2983-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/19/2011] [Indexed: 10/16/2022]
Abstract
Testicular descent is a complex developmental process involving anatomical and hormonal regulation. The gubernaculum undergoes a "swelling reaction" during the transabdominal phase and is mainly under the control of Insulin-Like Peptide 3 (INSL-3) and Mullerian Inhibitory Substance/Anti-Mullerian Hormone (MIS/AMH). The second phase of testicular descent is regulated by androgens and calcitonin gene-related peptide (CGRP) release from the sensory nucleus of the genitofemoral nerve (GFN). In rodents, the active proliferation of the gubernacular tip and cremaster muscle, its rhythmic contraction, as well as the chemotactic gradient provided by the CGRP result in eventual migration of the testis into the scrotum. This review illustrates the structural aspects and hormonal control of cremaster muscle development to better understand the mechanism of testicular descent in normal rodents and humans, compared to diseased rodent models. The analysis showed the cremaster muscle is formed from mesenchymal differentiation of the gubernacular tip and is not a direct passive extension of internal oblique muscle. Cremaster muscle matures slower than other body muscles, and the persistence of immature myogenic proteins seen in cardiac muscle allows rhythmic contraction to guide the testis into the scrotum. Finally, remodelling of the cremaster muscle enables gubernacular eversion. Further understanding of the molecular regulators governing the structural and hormonal changes in the cremaster muscle may lead to new advances in the treatment of undescended testes.
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Affiliation(s)
- Gabrielle Lie
- Douglas Stephens Surgical Research Unit, Murdoch Childrens Research Institute, Melbourne, Australia
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Ferlin A, Zuccarello D, Garolla A, Selice R, Foresta C. Hormonal and genetic control of testicular descent. Reprod Biomed Online 2008; 15:659-65. [PMID: 18062862 DOI: 10.1016/s1472-6483(10)60532-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cryptorchidism has the potential to affect the health of the human male. Although it is often considered a mild malformation, it represents the best-characterized risk factor for reduced fertility and testicular cancer. The aetiology of cryptorchidism remains, for the most part, unknown and cryptorchidism itself might be considered a complex disease. This reflects the intricate mechanisms regulating testicular development and descent from intra-abdominal location into the bottom of the scrotum, involving different anatomical and hormonal factors. Major actors of testicular descent are the Leydig cell-derived hormones testosterone and insulin-like factor 3, even if other factors may play a role. Although considerable evidence exists in animals to support a genetic cause, the genetic contribution to human cryptorchidism is only recently being elucidated. Environmental factors might also contribute to the aetiology of cryptorchidism and its increased incidence in recent years. Mutations in the gene for insulin-like factor 3 and its receptor and in the androgen receptor gene explain a minority of cases of cryptorchidism, but research on genetic polymorphisms that may also influence susceptibility to endocrine disruptors is shedding light on this field.
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Affiliation(s)
- Alberto Ferlin
- University of Padova, Department of Histology, Microbiology and Medical Biotechnologies, Centre for Male Gamete Cryopreservation, Via Gabelli 63, 35121 Padova, Italy.
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Shenker NS, Huynh J, Farmer PJ, Hutson JM. A new role for androgen in testicular descent: permitting gubernacular cell proliferation in response to the neuropeptide, calcitonin gene-related peptide. J Pediatr Surg 2006; 41:407-12. [PMID: 16481260 DOI: 10.1016/j.jpedsurg.2005.11.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND/PURPOSE Cell proliferation at the gubernacular tip increases in response to exogenous calcitonin gene-related peptide (CGRP) during migration into the scrotum. Calcitonin gene-related peptide is contained in the masculinized sensory branches of the genitofemoral nerve. We tested the independent effects of chemical sensory nerve disruption and prenatal androgen blockade on the in vitro gubernacular proliferative response to CGRP. METHODS Neonatal Sprague-Dawley rats were injected with capsaicin, a sensory nerve toxin, and gubernacula dissected 2 days later (D2). Sprague-Dawley dams were injected with flutamide, an androgen receptor antagonist, between days 15 and 19 of gestation. Flutamide pretreated males, and normal neonatal rats, were dissected at D0 and D2. Gubernacula were cultured for 24 hours +/- CGRP, pulse-labelled for the last 4 hours of culture with bromodeoxyuridine, a thymidine analogue marker for DNA replication, sectioned, and stained using immunohistochemistry. The percentage of positively staining cells in the gubernacular tip was calculated from three separate counts by a blinded observer and compared using analysis of variance. RESULTS Normal D0 gubernacular tips showed a significant response of cell proliferation to exogenous CGRP (34% vs 9% in controls, P < .001), which resolved by day 2 (16% vs 12%, P > .05). Calcitonin gene-related peptide markedly increased cell proliferation in D2 capsaicin pretreated gubernacula compared with controls (25% vs 14%, P < .01) and normal D2 gubernacula cultured with CGRP (P < .01). D0 flutamide pretreated cultured with CGRP showed no increase in cell proliferation compared with controls (16% vs 11%), but a small response was seen by D2 (19% vs 9%, P < .05). There was no significant difference between proliferation rates in the control groups. CONCLUSIONS Sensory innervation interruption sensitises the gubernaculum to exogenous CGRP, suggesting upregulation of CGRP receptors. In contrast, androgen blockade abolishes the increased rate of cell proliferation within the gubernacular tip. We conclude that androgens are necessary to "preprogramme" the proliferative response of the gubernaculum to CGRP.
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Affiliation(s)
- Natalie S Shenker
- Department of General Surgery, Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria 3052, Australia
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Vigueras RM, Moreno-Mendoza N, Reyes G, Merchant-Larios H. Androgen receptor and calcitonin gene-related peptide in neurons of the genitofemoral nerve during testicular descent induced with human chorionic gonadotropin. Arch Med Res 2004; 34:166-70. [PMID: 14567394 DOI: 10.1016/s0188-4409(03)00040-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Low levels of circulating testosterone during testis descent cause cryptorchidism in humans and rats. Treatment with human chorionic gonadotrophin (hCG) induces testis descent by stimulating production of testosterone (T). Neurons of genitofemoral nerve (GFN), which innervate testicular gubernaculum, may play a role in testis descent. METHODS In the current study, putative correlations were made between T and GFN motor and sensory neuron activity during inguinoscrotal testis descent. Cryptorchidism was provoked in prepuberal rats with estradiol. Rats with testicular descent induced with hCG and cryptorchid controls were used. Cells of spinal cord and dorsal root ganglia were labeled by retrograde staining with fast-blue. Expression of androgen receptor (AR) and calcitonin gene-related peptide (CGRP) were detected with indirect immunofluorescence. RESULTS Neurons labeled with fast-blue were found in the center of motor horn and dorsal root ganglia at levels L1 and L2. While number of motor neurons expressing AR was significantly higher in the group treated with hCG, number expressing CGRP was higher in controls. In dorsal root ganglion, number of cells immunostained with CGRP antibody was similar in both groups but AR was not detected. CONCLUSIONS Present results support the hypothesis that motor nucleus of the GFN is a direct target of testosterone and that regulation of CGRP in sensory nucleus may be involved in testicular descent.
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Affiliation(s)
- Rosa María Vigueras
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
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HRABOVSZKY ZOLTAN, FARMER PAMELAJ, HUTSON JOHNM. UNDESCENDED TESTIS IS ACCOMPANIED BY CALCITONIN GENE RELATED PEPTIDE ACCUMULATION WITHIN THE SENSORY NUCLEUS OF THE GENITOFEMORAL NERVE IN TRANS-SCROTAL RATS. J Urol 2001. [DOI: 10.1016/s0022-5347(05)66594-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- ZOLTAN HRABOVSZKY
- From the F. Douglas Stephens Surgical Research Laboratory, Royal Children’s Hospital Research Institute, Melbourne, Australia
| | - PAMELA J. FARMER
- From the F. Douglas Stephens Surgical Research Laboratory, Royal Children’s Hospital Research Institute, Melbourne, Australia
| | - JOHN M. HUTSON
- From the F. Douglas Stephens Surgical Research Laboratory, Royal Children’s Hospital Research Institute, Melbourne, Australia
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UNDESCENDED TESTIS IS ACCOMPANIED BY CALCITONIN GENE RELATED PEPTIDE ACCUMULATION WITHIN THE SENSORY NUCLEUS OF THE GENITOFEMORAL NERVE IN TRANS-SCROTAL RATS. J Urol 2001. [DOI: 10.1097/00005392-200103000-00079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Hrabovszky Z, Farmer PJ, Hutson JM. Does the sensory nucleus of the genitofemoral nerve have a role in testicular descent? J Pediatr Surg 2000; 35:96-100. [PMID: 10646783 DOI: 10.1016/s0022-3468(00)80022-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND/PURPOSE A role for the genitofemoral nerve (GFN) and its neurotransmitter, CGRP, in testicular descent has been well established. The exact mechanism, however, by which circulating androgens act on the GFN is not yet known. The authors studied the sensory nucleus of the GFN (L1-L2 dorsal root ganglia [DRG]) to determine whether it is sexually dimorphic and able to be influenced by intrauterine antiandrogen treatment. METHODS Sprague-Dawley rats were injected daily with 100 mg/kg/d of the antiandrogen flutamide on day 16 to 19 of pregnancy. Control animals were treated with vehicle only. At the age of 2 to 3 days the newborn rats underwent unilateral dissection of the GFN. The proximal end was labelled with fluorescent dye, diamidinophenyl indole. The rats were killed 48 hours later, and the relevant ganglia (L1,L2) were removed. Cryostat frozen serial sections were cut, and retrogradely labelled fluorescent cells were counted under an epifluorescence microscope. In 32 animals, the cells were double fluorescent labelled with antibody to CGRP and FITC. RESULTS Of 75 rats evaluated, the mean number of the DAPI-positive, retrogradely labelled cells in the control groups was 266 +/- 55 in the male, and 230 +/- 67 in the female as opposed to 186 +/- 45 and 161 +/- 35 in the flutamide-treated male and female groups, respectively. In 32 animals the DRG sections were double labelled for CGRP. The number of CGRP plus DAPI-positive cells were as follows: control males, 60 +/-12; control females, 50 +/- 9; flutamide males, 36 +/- 8; flutamide females, 40 +/- 10. CONCLUSIONS These findings show a sexual dimorphism in the number of GFN cell bodies in the DRG. Flutamide decreases the number of GFN cell bodies in the DRG of both males and females. Our results are consistent with a role for circulating androgens acting on the sensory nucleus of the GFN (DRG) instead of the motor nucleus as previously thought. The release of CGRP from the nerve endings may occur via the sensory branch of the GFN.
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Affiliation(s)
- Z Hrabovszky
- F. Douglas Stephens Surgical Research Laboratory, Royal Children's Hospital Research Institute, Melbourne, Australia
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Abstract
BACKGROUND/PURPOSE Calcitonin gene-related peptide (CGRP) may stimulate gubernacular migration during testicular descent by release from the genitofemoral nerve (GFN). The origin of CGRP within the nerve, however, is controversial. This study examines whether sensory nerve destruction alters gubernacular contractility in vitro in Sprague-Dawley (SD) and congenitally cryptochid (TS) rats. METHODS Part 1: Twenty-four SD and 16 TS rats (day 0) had either both GFNs transected or sham operation. Gubernacula were removed on day 2 and cultured with or without CGRP (714 nmol/L). Contractility was recorded by video. Part 2: Twenty-two SD and 17 TS rats (day 0) were injected with either capsaicin or vehicle. Gubernacula were removed (day 2) and cultured as above. RESULTS Part 1: In sham-operated SD rats gubernacular contracility increased from 8% to 83% with added CGRP. After GFN transection contractility was not affected by CGRP (21% without and 86% with CGRP; not significant). TS rat gubernacula had no endogenous contractions, but after GFN transection, the contractile response to CGRP increased from 6% to 44% (P = .04). Part 2: In vehicle-treated SD rats, rhythmic contractions increased from 10% to 86% with CGRP, which was unchanged by capsaicin treatment (82%; not significant). In vehicle-treated TS rats, gubernacular contractions were 6% after CGRP. After capsaicin pretreatment, contractions increased to 59% with CGRP (P = .002). CONCLUSIONS Results of this study show that chemical destruction of sensory nerves restores gubernacular contractility in mutant cryptorchid TS rats. Release of CGRP appears to occur through sensory nerves.
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Affiliation(s)
- Z Hrabovszky
- F. Douglas Stephens Surgical Research Laboratory, Royal Children's Hospital Research Institute, Melbourne, Australia
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Clarnette TD, Hutson JM. Exogenous calcitonin gene-related peptide can change the direction of gubernacular migration in the mutant trans-scrotal rat. J Pediatr Surg 1999; 34:1208-12. [PMID: 10466597 DOI: 10.1016/s0022-3468(99)90153-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
PURPOSE The mutant trans-scrotal (TS) rat shows unilateral or bilateral suprainguinal testes in more than 70% of males. Calcitonin gene-related peptide (CGRP) has been proposed as the neurotransmitter released from the genitofemoral nerve (GFN), which controls gubernacular migration to the bottom of the scrotum during inguinoscrotal descent. Results of previous studies in this rat suggest a down-regulation of CGRP receptors in gubernaculum occurring caused by excess release of the neuropeptide from the GFN. The aim of this study was to test the hypothesis that division of the GFN in neonatal TS rats, potentially allowing the gubernaculum to become sensitive to CGRP, followed by exogenous CGRP injections, would change the direction of gubernacular migration and the final position of the testis. METHODS Four study groups were used: group 1 (n = 43), sham operation, in which the peritoneal cavity was opened and the left genitofemoral nerve was exposed but not divided, and oil injections into left hemiscrotum; group 2 (n = 70), division of left GFN and CGRP injections into left hemiscrotum; group 3 (n = 36), sham operation and CGRP injections into left hemiscrotum; group 4 (n = 30), division of left GFN and oil injections into left hemiscrotum. RESULTS In group 2 (GFN division and CGRP injection), 18 testes were located in a position not previously described in this model. In 16 (23%) rats, the testis was located at the entrance of the internal inguinal ring with the gubernaculum directed down toward the scrotum. This contrasts with the normal position of the testis in the superficial inguinal pouch, where the testis is located superficial to the external oblique muscle, with the gubernaculum directed craniolaterally. In two (3%) rats, there was incomplete descent of the testis. In group 3 (sham operation and CGRP injection), two (6%) testes were located at the internal ring. The remaining testes in the above groups and all of the testes in groups 1 and 4 were found in either the superficial inguinal pouch, completely descended, or adherent to scar tissue. CONCLUSIONS These findings suggest that division of the GFN in neonatal TS rats followed by CGRP injections into the scrotum can change the direction of gubernacular migration in the TS rat. The effectiveness of this experimental model is limited by the inability to accurately localize injected CGRP into the scrotum.
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Affiliation(s)
- T D Clarnette
- F. Douglas Stephens Surgical Research Laboratory, Royal Children's Hospital Research Institute, Melbourne, Australia
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Terada M, Hutson JM, Farmer PJ, Goh DW. The Role of the Genitofemoral Nerve and Calcitonin Gene-Related Peptide in Congenitally Cryptorchid Mutant TS Rats. J Urol 1995. [DOI: 10.1016/s0022-5347(01)67148-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Masaru Terada
- Department of General Surgery, Royal Children's Hospital, Melbourne, Australia
| | - John M. Hutson
- Department of General Surgery, Royal Children's Hospital, Melbourne, Australia
| | - Pamela J. Farmer
- Department of General Surgery, Royal Children's Hospital, Melbourne, Australia
| | - Day Way Goh
- Department of General Surgery, Royal Children's Hospital, Melbourne, Australia
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Hutson JM. Testicular descent: the first step towards fertility. INTERNATIONAL JOURNAL OF ANDROLOGY 1994; 17:281-8. [PMID: 7744506 DOI: 10.1111/j.1365-2605.1994.tb01257.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- J M Hutson
- Department of Paediatrics, Royal Children's Hospital, University of Melbourne, Victoria, Australia
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