The role of smooth muscle cell differentiation in the mechanism of obliteration of processus vaginalis.
OBJECTIVE
Development of indirect inguinal hernia and hydrocele in childhood is readily explained by the persistence of smooth muscle component around the processus vaginalis (PV) after the descent of the testis into the scrotum. The aim of this study was to investigate the expression of smooth muscle myosin heavy chain (SM MHC) isoforms as the markers of smooth muscle cell (SMC) differentiation in childhood inguinal hernia and hydrocele and in age-matched controls.


METHODS
The authors analyzed sacs from patients with inguinal hernia (male, 10; female, 10) and hydrocele (n = 10) immunohistochemically using monoclonal antibodies against alpha-smooth muscle actin, SM1, SM2 and SMemb. Peritoneal samples (male, 5; female, 5) obtained from age-matched patients served as controls. Immunostaining was evaluated with semiquantitative scoring and chi2 test.


RESULTS
The expression pattern of SM MHC isoforms did not differ among sacs obtained from female inguinal hernia when compared with that of controls. However, strong expression of SMemb within the sac walls of male inguinal hernia and SM1 in hydrocele groups were observed.


CONCLUSIONS
Our results indicate that SMC differentiation may play an important role in the obliteration of processus vaginalis in male inguinal hernia and hydrocele after the descent of the testis.
Hosgor
Munevver
M
Department of Pediatric Surgery, Dr. Behcet Uz Children's Hospital, Izmir, Turkey.
Karaca
Irfan
I
Ozer
Erdener
E
Erdag
Gulsun
G
Ulukus
Cagnur
C
Fescekoglu
Orhan
O
Aikawa
Masanori
M
D000199:Actins / Q000032:analysis; D015415:Biomarkers / Q000032:analysis; D002454:Cell Differentiation; D002675:Child, Preschool; D005260:Female; D006552:Hernia, Inguinal / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009130:Muscle, Smooth / Q000473:pathology*; D018995:Myosin Heavy Chains / Q000032:analysis*; D010537:Peritoneum / Q000473:pathology; D012016:Reference Values; D006848:Testicular Hydrocele / Q000473:pathology* / Q000601:surgery
D000199:Actins; D015415:Biomarkers; D018995:Myosin Heavy Chains