Cremaster muscle is not sexually dimorphic, but that from boys with undescended testis reflects alterations related to autonomic innervation

doi:10.1053/jpsu.2001.23959

Journal of Pediatric Surgery

Volume 36, Issue 6, June 2001, Pages 877-880

https://doi.org/10.1053/jpsu.2001.23959 Get rights and content

Abstract

Background/Purpose: The genitofemoral nerve and its motor neuron are known to be sexually dimorphic. An association has been suggested to exist between antiandrogen-induced undescended testis and the genitofemoral nerve. Therefore, the cremaster muscles (CM) from boys and girls with inguinal hernia and boys with undescended testis were compared to evaluate the failed descent through sexual dimorphism. Methods: Samples of CM were obtained from 10 boys and 10 girls with inguinal hernia and 10 boys with undescended testis. Sections were stained for ATPase reactions after acid and alkaline preincubations, and for the expression of myosine heavy chains. The percentages of type 1 and type 2 fibers, and mean diameters of fibers according to the types were determined for each group. Values were compared through Mann-Whitney U test, and P values less than.05 were considered to be significant. Results: CM have mainly been composed of type 1 fibers. Distributions of type 1 and 2 fibers have not shown a difference among groups. Mean diameters of both type 1 and type 2 fibers from girls (P <.05), and mean diameter of type 2 fibers from boys with undescended testis have been significantly smaller than those encountered in boys with inguinal hernia (P <.05). Conclusions: Although the mean diameter of type 1 fibers from boys with undescended testis has been as large as those encountered in boys with inguinal hernia, mean diameter of type 2 fibers has been as small as those encountered in girls. Among various reasons to selectively diminish the size of type 2 fibers, lack of beta adrenergic effect appears to be the most satisfactory explanation. J Pediatr Surg 36:877-880. Copyright © 2001 by W.B. Saunders Company.

Section snippets

Materials and methods

After obtaining a written consent, samples of CM were obtained from 10 boys and 10 girls with inguinal hernia and 10 boys with undescended testis at similar ages. The patients have been without any additional pathology including the neurologic or muscular diseases.

Samples were obtained from the identical localization within the inguinal canals. After opening the anterior wall of the inguinal canal, the CM overlying the sac was biopsied before any attempts at dissection.

The CM were frozen in

Results

Mean ages of the boys and girls presenting with inguinal hernia, and boys presenting with undescended testis have been 28.2 ± 3.47, 33.5 ± 8.27, and 33.1 ± 5.12 months, respectively (Table 1).None of the groups has shown a significant difference compared with others.

The CM of the boys and girls presenting with inguinal hernia, and boys presenting with undescended testis have contained significantly more type 1 than type 2 fibers (P <.001; Table 1). However, either type 1 or type 2 percentages

Discussion

The CM obtained from children with an inguinal hernia may have limited the evaluation of sexual dimorphism. However, the CM associated with inguinal hernia have been shown previously to reveal minimal histopathologic changes.8, 9 Furthermore, the patients from both sexes have had the same anomaly. Therefore, we have considered those CM suitable for the evaluation of sexual dimorphism.

The levator ani muscle is well developed in male rats. However, it is very atrophied in female rats. The

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Among cremaster muscles, those obtained from boys with undescended testis reveal significant neurologic alterations

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Cited by (33)

Developmental genetics of the male reproductive system
2023, Human Reproductive and Prenatal Genetics
Male reproductive development is a complex process requiring precise endocrine and genetic signals to regulate morphological changes. In this chapter, we review the genetic cues that induce male sexual differentiation from the bipotential gonad and genital tubercle to the development of the testes and penis, respectively. To begin, SRY production in XY gonads initiates the male pathway there by inducing testicular development and Mullerian regression. The newly formed testes must then descend into the scrotum to later produce functional sperm. Testicular descent is a biphasic process consisting of INSL3-dependent transabdominal descent and androgen-dependent inguinoscrotal descent. Many genes involved in testicular development are also integral in the development of the external genitalia. The external genitalia develops from a sexually undetermined genital tubercle that undergoes hormone-driven sexually dimorphic development. Finally, we examine birth defects that can arise from perturbations in the intricate system that regulates normal male reproductive development.
Long-term testicular position and growth of acquired undescended testis after prepubertal orchidopexy
2012, Journal of Pediatric Surgery
Citation Excerpt :
The present study shows that after prepubertal orchidopexy, in unilateral cases, the growth of the operated testis seems to be retarded in comparison with both its contralateral counterpart and with the values reported in the literature. Several studies have shown that UDT that had been treated surgically in childhood is smaller in adulthood than normal testes [31-34]. This may be caused by the primary condition of the testis (prenatal dysgenesis) [34], the surgical trauma [31], or both.
The aim of the study was to determine long-term testicular position and growth of acquired undescended testis (UDT) after prepubertal orchidopexy.
Patients who had undergone prepubertal orchidopexy for acquired UDT at our hospital between 1986 and 1999 were recruited to assess long-term testicular position and volume. Testis position was assessed by physical examination. Testis volume was measured with Prader orchidometry and ultrasound and was compared with normative values reported in the literature.
A total of 105 patients (aged 14.0-31.6 years) were included with 137 acquired UDT (32 bilateral, 33 left sided, and 40 right sided). All but 1 of the orchidopexied testes (99.3%) were in low scrotal position. The mean volume of the orchidopexied testes in unilateral UDT (n = 73, 10.57 ± 3.74 mL) differed significantly from the size of the testes at the contralateral side (14.11 ± 4.23 mL) (P = .000). The operated testes (10.28 ± 3.45 mL) were smaller than the mean adult testis volume reported in the literature (13.4-13.6 mL; cutoff, 13.2 mL).
Testis position after prepubertal orchidopexy for acquired UDT was nearly always low scrotal. The volume of the orchidopexied testes was smaller than both the volume of the contralateral testes and the normative values reported in the literature.
Cremaster muscle myogenesis in the tip of the rat gubernaculum supports active gubernacular elongation during inguinoscrotal testicular descent
2011, Journal of Urology
Cryptorchidism is a common abnormality and normal testicular descent is controlled by the gubernaculum. The cremaster may originate from abdominal muscles during gubernacular eversion or alternatively it may develop inside the gubernaculum. We studied cremaster myogenesis to determine how it develops.
Coronal sections of the pelvis were prepared from male Sprague-Dawley® rats and from males treated prenatally with the antiandrogen flutamide at embryonic day 19, and postnatal days 10, 19 and 35 after receiving ethical approval. Immunohistochemical stains were prepared for Ki67, Pax-7, myogenin, myosin heavy chain 7, Myh1, Myh2, Myh4, embryonic myosin, and slow and cardiac troponin T. Cell counts of the 1) gubernacular tip, 2) proximal gubernaculum/cremaster muscle and 3) adjacent abdominal wall are shown as a percent of positive fibers or positive cells per area.
Throughout embryonic day 19, and postnatal days 10 and 19 proliferation (Ki67) was maximal at the gubernacular tip (p <0.001), as were muscle stem cells markers (Pax-7 p <0.05), early myogenesis (myogenin p <0.001) and immature muscle (Myh7, and slow and cardiac troponin T p <0.0001). In contrast, secondary (fast twitch, Myh1, 2 and 4) fibers were more common in abdominal muscles (p <0.0001). Differences in muscle maturity and composition decreased with time. Flutamide treated rats showed more cellular proliferation than controls postnatally on postnatal day 10 (p <0.001) as well as persistent immature embryonic myosin at the tip from postnatal day 19 (p <0.05).
Results show that the rat cremaster muscle is more immature at the gubernacular tip, consistent with myogenesis occurring in the gubernaculum during migration to the scrotum, as proposed in humans.
Does chemical sympathectomy alter the ontogeny of gubernacular migration in vivo?
2007, Journal of Pediatric Surgery
Testicular descent occurs in several stages, but the exact mechanism remains obscure. Sympathetic nerves have been proposed to have a role by a possible action on developing cremaster muscle, following observations of sympathetic dysfunction in cremaster from boys with cryptorchidism. This study aimed to see if chemical sympathectomy affected testicular descent in rats.
Sprague-Dawley dams were injected with 6-hydroxydopamine (days 15-19; 75 μg/kg) or control vehicle alone, and male pups examined at 0 to 10, 20, 30, and 60 days of age. The length of the processus vaginalis was measured and sections taken for histology.
No difference in processus vaginalis growth was found between experimental and control groups, both macro- and microscopically. Chemical sympathectomy was confirmed by loss of adrenergic fibres in the adrenal cortex of experimental, but not control, animals.
These studies suggest that sympathetic innervation is not an important part of testicular descent in the rat but does not exclude a pathologic role in undescended testes or effects in humans only.
The role of sympathetic innervation in the developing rat gubernaculum
2007, Journal of Pediatric Surgery
Citation Excerpt :
Recently, a new theory implicating the sympathetic nerves in testicular descent has been proposed [9]. By examining the cremaster muscle and its physiological properties in specimens removed at orchidopexy, Tanyel et al found evidence for decreased beta-adrenergic nerves consistent with deficient sympathetic innervation in cryptorchidism [10-12]. These authors have gone on to suggest that rather than the sympathetic neuropathy being the result of the maldescent, it may be its cause.
Testicular descent occurs in several steps, but the mechanism remains unknown. Recently, sympathetic nerves have been proposed to have a role. This study aimed to see if adrenergic agonists and antagonists affected the neonatal rat gubernacular cremaster sac in organ culture.
Cremaster sacs were collected from 2-day-old Sprague-Dawley male rats (n = 90) and placed in organ culture with/without (1) calcium chloride (0.45-1.8 mmol/L), (2) rat calcitonin gene-related peptide (CGRP) (714 nmol/L), (3) nifedipine (0.1-100 nmol/L), (4) isopreneline (10 μmol/L), and (5) guanethidine (10 μmol/L). Gubernacula were observed over 2 days for rhythmic peristalsis (>120 beats per minute for >1 minute).
Addition of CGRP stimulated rhythmic contractility but only in the presence of calcium, with a dose-response to the level of calcium ions. Contractions induced by CGRP with calcium could be obliterated in a dose-response by nifedipine. Isoprenaline caused some increase in contractions with calcium but less than that seen with CGRP. No augmentation of effect was seen with CGRP and isopreneline together, and the level of contractility was the same with guanethidine.
Calcitonin gene-related peptide is the main effector for contractility of the rat cremaster sac, as long as calcium ions are present. Adrenergic agonists and antagonists had limited effects. Contractility could be inhibited with nifedipine, consistent with CGRP acting via a calcium-dependent pathway.
Androgen receptor immunostaining and androgen receptor messenger ribonucleic acid expression are increased in cremaster muscles associated with undescended testis
2006, Urology
To determine and compare androgen receptor (AR) immunostaining and AR messenger ribonucleic acid (mRNA) expression in cremaster muscles associated with descended or undescended testis.
Eight boys with descended testis but with inguinal hernia and 8 boys with undescended testis were evaluated. Serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, and free testosterone levels were determined, and samples of cremaster muscles were immunostained for AR. Groups were compared by unpaired t tests and Fisher’s exact tests; P values of <0.05 were considered significant. Samples of cremaster muscles were obtained from another 5 boys with descended testis but with inguinal hernia and 5 boys with undescended testis. The expression of AR mRNA in those samples was determined by semiquantitative reverse transcriptase polymerase chain reaction.
Serum FSH, LH, testosterone, and free testosterone levels were similar among groups. None of the samples from boys with descended testis showed positive staining, but 4 of 8 samples from boys with undescended testis stained positive for AR. Androgen receptor mRNA transcript levels were approximately 10 times lower in cremaster muscles of boys with descended testis compared with those in boys with undescended testis.
Despite similar serum hormone levels, more AR expression in cremaster muscles associated with undescended testis might represent evidence of being subjected to a lesser degree of androgenic effects.

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^☆: Address reprint requests to F. Cahit Tanyel, MD, Hacettepe University, Children's Hospital, Department of Pediatric Surgery, 06100 Ankara, Turkey.

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ArticlesCremaster muscle is not sexually dimorphic, but that from boys with undescended testis reflects alterations related to autonomic innervation☆

Abstract

Section snippets

Materials and methods

Results

Discussion

Febs Lett

J Pediatr Surg

J Urol

J Pediatr Surg

Early Hum Dev

Curr Biol

J Pediatr Surg

Brain Res

Neuroscience

A reevaluation of the mechanism of testicular descent: Mechanisms for failed descent or ascent

J Pediatr Surg

Lack of carbachol response indicates the absence of cholinergic receptors in sacs associated with undescended testis

J Pediatr Surg

Muscle fiber types: How many and what kind?

Arch Neurol

Among cremaster muscles, those obtained from boys with undescended testis reveal significant neurologic alterations

BJU Int

Articles
Cremaster muscle is not sexually dimorphic, but that from boys with undescended testis reflects alterations related to autonomic innervation☆