The testicular descent in the rat: a scanning electron microscopic study.
OBJECTIVE
Numerous researchers studied the morphology of testicular descent including the possible function of gubernaculum. However, a clear illustration of this process is still missing. The aim of this study was to illustrate testicular descent using scanning electron microscopy (SEM) in a rat model.


METHODS
The abdomen of rat fetuses between gestational day (E) 15 and E 22 and newborns at postnatal day (D) 0 and D 1.5 was opened by microsurgery. Standard preparation for SEM was carried out. The position of the testis and gubernaculum testis was documented.


RESULTS
The gubernaculum was obvious in male rat embryos at E 17.5. In a first phase (E 16-E 21) the testis moved from cranio-lateral and dorsal to caudo-medial and ventral, while clear signs of an active role of the gubernaculum were missing. In a second phase (E 22-D 1.5) the processus vaginalis peritonei (PVP) developed, while the conus of the gubernaculum disappeared, after which, the testis moved out of the abdominal cavity and entered the PVP.


CONCLUSIONS
In our study, we could not specify the role of gubernaculum for testicular descent. However, our data showed that the testis lay intraperitoneal throughout the descensus testis.
Fiegel
Henning C
HC
Department of Pediatric Surgery, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany. henning.fiegel@kgu.de
Rolle
Udo
U
Metzger
Roman
R
Geyer
Christian
C
Till
Holger
H
Kluth
Dietrich
D
D000818:Animals; D000831:Animals, Newborn; D004622:Embryo, Mammalian; D005333:Fetus; D008297:Male; D008855:Microscopy, Electron, Scanning; D023421:Models, Animal; D051381:Rats; D017207:Rats, Sprague-Dawley; D013737:Testis / Q000502:physiology* / Q000648:ultrastructure*
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