Collagen and elastic fibers in the penis of human fetuses at 28 weeks postconception.
OBJECTIVE
The extracellular matrix is a key element in penile function and pathology, yet little is known of its development. Herein we investigated the morphological organization of collagen and elastin in the corpora cavernosa and tunica albuginea of human fetuses.


METHODS
The penises from 5 fresh human fetuses at 28 weeks postconception (WPC) were routinely fixed and embedded, and all staining procedures were carried out on paraffin sections. Collagen was evidenced by staining with: (1) Gomori's trichrome; (2) sirius red, followed by observation under polarized light, and (3) an antihuman collagen type-III antibody. Elastin and the whole elastic system were revealed using an antihuman elastin antibody and Weigert's resorcin fucsin, respectively.


RESULTS
At this stage of fetal development, the albuginea is formed predominantly by dense bundles of collagen. Near the corpora cavernosa, the presence of type-III collagen was also observed. Weigert staining showed numerous fibers of the elastic system in the albuginea. Type-III collagen was found to be strongly positive in the cavernous trabeculae and in the connective sheath surrounding the central artery. Using Weigert staining and an immunolabeling method with primary antibody against human elastin, we found an important quantity of elastic system fibers in the trabeculae of the corpora cavernosa.


CONCLUSIONS
In fetuses at 28 WPC the albuginea is formed predominantly by dense bundles of collagen. The trabecular structures of the corpora cavernosa present a significant quantity of type-III collagen and elastic system fibers.
Urogenital Research Unit, Biomedical Center, State University of Rio de Janeiro, UERJ, Brazil.
A L
AL
Bastos
W S
WS
Costa
L E
LE
Cardoso
F J
FJ
Sampaio
D003094:Collagen / Q000378:metabolism*; D004547:Elastic Tissue / Q000196:embryology; D004549:Elastin / Q000378:metabolism*; D005333:Fetus / Q000378:metabolism; D005865:Gestational Age; D006801:Humans; D008297:Male; D010413:Penis / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D013194:Staining and Labeling
D003094:Collagen; D004549:Elastin