Quantitative analysis of sacral parasympathetic nucleus innervating the rectum in rats with anorectal malformation.
OBJECTIVE
The purpose of this experiment was to identify the neurons in the lumbosacral spinal cord involved in colon-rectal function and to compare normal and anorectal malformation of fetal rats.


METHODS
The authors quantified the sacral parasympathetic nucleus (SPN) innervation of the rectum by Fluorogold (FG) (Fluorochrome, Englewood, CO) retrograde tracing experiment in fetal rats with normal and anorectal malformation. Anorectal malformation was induced in rat fetuses by ethylenethiourea (ETU). The number of FG-labeled SPNs was scored and compared between male fetuses with or without malformation in the ETU-fed group and control groups.


RESULTS
The number of FG-labeled SPNs in the fetuses without a defect, with ETU injected but without any defects of the anorectum or neural tube, with low-type deformity, and with high-type deformity were (mean +/- SEM) 47.3 +/- 2.9, 45.6 +/- 3.2, 24.2 +/- 3.8, and 8.5 +/- 2.5, respectively. Fluorogold-labeled SPNs in the fetuses with high-type deformity were significantly fewer than those in fetuses without defects (P<.05) and in controls (P < .05).


CONCLUSIONS
These findings suggest that defective SPN innervation to the rectum is a primary anomaly that coexists with the alimentary tract anomaly in anorectal malformation during fetal development. The intrinsic neural deficiency is an important factor likely to contribute to poor postoperative anorectal function despite surgical correction of the malformation.
Jia
Huimin
H
Department of Paediatric Surgery, The 2nd Clinical College of China Medical University, Shenyang 110004, PR China.
Zhang
Keren
K
Zhang
Shucheng
S
Yuan
Zhengwei
Z
Bai
Yuzuo
Y
Wang
Weilin
W
D001003:Anal Canal / Q000002:abnormalities / Q000294:innervation*; D000818:Animals; D003248:Constipation / Q000209:etiology / Q000503:physiopathology; D005031:Ethylenethiourea; D005260:Female; D008161:Lumbosacral Region; D008297:Male; D010275:Parasympathetic Nervous System / Q000166:cytology*; D051381:Rats; D017208:Rats, Wistar; D012007:Rectum / Q000002:abnormalities* / Q000294:innervation*
D005031:Ethylenethiourea