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Home / Equine Research Bank / Reproduction / Cryptorchidism in common eutherian mammals.
Reproduction (Cambridge, England)2007; 133(3); 541-561; doi: 10.1530/REP-06-0272

Cryptorchidism in common eutherian mammals.

Abstract: Cryptorchidism is failure of one or both testes to descend into the scrotum. Primary fault lies in the testis. We provide a unifying cross-species interpretation of testis descent and urge the use of precise terminology. After differentiation, a testis is relocated to the scrotum in three sequential phases: abdominal translocation, holding a testis near the internal inguinal ring as the abdominal cavity expands away, along with slight downward migration; transinguinal migration, moving a cauda epididymidis and testis through the abdominal wall; and inguinoscrotal migration, moving a s.c. cauda epididymidis and testis to the bottom of the scrotum. The gubernaculum enlarges under stimulation of insulin-like peptide 3, to anchor the testis in place during gradual abdominal translocation. Concurrently, testosterone masculinizes the genitofemoral nerve. Cylindrical downward growth of the peritoneal lining into the gubernaculum forms the vaginal process, cremaster muscle(s) develop within the gubernaculum, and the cranial suspensory ligament regresses (testosterone not obligatory for latter). Transinguinal migration of a testis is rapid, apparently mediated by intra-abdominal pressure. Testosterone is not obligatory for correct inguinoscrotal migration of testes. However, normally testosterone stimulates growth of the vaginal process, secretion of calcitonin gene-related peptide by the genitofemoral nerve to provide directional guidance to the gubernaculum, and then regression of the gubernaculum and constriction of the inguinal canal. Cryptorchidism is more common in companion animals, pigs, or humans (2-12%) than in cattle or sheep (< or =1%). Laboratory animals rarely are cryptorchid. In respect to non-scrotal locations, abdominal testes predominate in cats, dogs, and horses. Inguinal testes predominate in rabbits, are common in horses, and occasionally are found in cats and dogs. S.c. testes are found in cattle, cats and dogs, but are most common in humans.
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Publication Date: 2007-03-24 PubMed ID: 17379650DOI: 10.1530/REP-06-0272Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research article provides a comprehensive study on cryptorchidism, a condition where one or both testes fail to descend into the scrotum in common eutherian mammals. The study introduces a unified interpretation of testis descent and emphasizes the importance of accurate terminology.

Understanding Cryptorchidism

  • According to the research, the primary fault of Cryptorchidism lies in the testis itself. The testis is relocated to the scrotum in a three-step process: abdominal translocation, transinguinal migration, and inguinoscrotal migration. Specifically, cryptorchidism is characterized and understood through the following key factors:
    • The testis initially gets relocated near the internal inguinal ring as the abdominal cavity expands away. This is marked by a slight downward migration process.
    • Following this, the cauda epididymidis and testis move through the abdominal wall in a process known as transinguinal migration.
    • Finally, the cauda epididymidis and testis are moved to the bottom of the scrotum in a process known as inguinoscrotal migration.

Contribution of Insulin-Like Peptide 3 and Testosterone

  • During the first phase of testis relocation, the gubernaculum (an anatomical structure in males that guides the testis descent) enlarges under the stimulation of insulin-like peptide 3, helping to anchor the testis in place. Concurrently, testosterone plays an important role in the masculinization of the genitofemoral nerve (a nerve in the pelvic region).
  • The research also reveals that testosterone is not necessary for the correct migration of testes to the scrotum, but typically stimulates the growth of the vaginal process and provides directional guidance to the gubernaculum.

Rate of Cryptorchidism in Various Species

  • The occurrence of the condition of cryptorchidism varies across species. It is found to be more common in companion animals, pigs, and humans with 2-12% occurrence rate than in cattle or sheep, which have an occurrence rate less than or equal to 1%.
  • Interestingly, the location of the abdominal testes also differs among species. They are predominantly found in cats, dogs, and horses. Inguinal testes are more common in rabbits and horses but can sometimes be found in cats and dogs. Subcutaneous (s.c.) testes are found in cattle, cats, and dogs, but are most common in humans.

Cite This Article

APA
Amann RP, Veeramachaneni DN. (2007). Cryptorchidism in common eutherian mammals. Reproduction, 133(3), 541-561. https://doi.org/10.1530/REP-06-0272

Publication

Reproduction (Cambridge, England)
ISSN: 1470-1626
NlmUniqueID: 100966036
Country: England
Language: English
Volume: 133
Issue: 3
Pages: 541-561

Researcher Affiliations

Amann, R P
  • Animal Reproduction and Biotechnology Laboratory, Colorado State University, Fort Collins, Colorado 80523-1683, USA. rpalra63@msn.com
Veeramachaneni, D N R

    MeSH Terms

    • Animals
    • Cryptorchidism / embryology
    • Gestational Age
    • Humans
    • Inguinal Canal / embryology
    • Male
    • Mammals / embryology
    • Organogenesis
    • Scrotum / embryology
    • Sex Differentiation
    • Testis / embryology
    • Testosterone / physiology

    Grant Funding

    • 1R21-ES014607-01 / NIEHS NIH HHS

    References

    This article includes 107 references

    Citations

    This article has been cited 47 times.
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