Quantitative analysis of smooth muscle fibers in corpus cavernosum of human fetuses.
OBJECTIVE
Quantify objectively the normative distribution and the percentage of smooth muscle fibers in the corpus cavernosum of human fetuses with 24 weeks post-conception (WPC) of gestational age.


METHODS
We studied 7 penises taken from 7 fresh human fetuses. We analyzed 5 randomized sections from each penis and in every section we analyzed 3 fields, totaling 15 fields per penis and 105 fields for the final results. Immunohistological staining for the smooth muscle fibers was used to accentuate the differences between the intracavernous structures (smooth muscle fibers and collagen fibers). The fields studied were digitized with a final magnification of 450X and a computerized analysis of the smooth muscle fibers was performed with image analyzer software. The percentage of smooth muscle fibers per standard square area was estimated and the mean value was used for each penis.


RESULTS
The distribution of smooth muscle fibers in the corpus cavernosum of human fetuses with 24 WPC of gestational age ranged from 17.52% to 27.76% of the total area. The mean value was 22.72% and the standard deviation was 3.56.


CONCLUSIONS
Our results show that the percentage of smooth muscle cells in corpus cavernosum of human fetuses with 24 WPC of gestational age is significantly smaller when compared with the data available for adult cadavers.
Sampaio
F J
FJ
Urogenital Research Unit, State University of Rio de Janeiro, Brazil.
Pinto
J L
JL
Silva-Costa
W
W
Pereira
M J
MJ
D005333:Fetus / Q000166:cytology*; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D009130:Muscle, Smooth / Q000166:cytology / Q000196:embryology*; D010413:Penis / Q000166:cytology / Q000196:embryology