The myenteric plexus of the rat colon after fecal stream diversion: a morpho-quantitative study.
The myenteric plexus undergoes adaptive changes under several conditions. Mucosal and muscular alterations of the colon have been described after fecal stream diversion but studies concerning the myenteric plexus after this procedure are scarce. Therefore, 28 Wistar rats were submitted to fecal diversion and followed for different periods (30, 60, 120 and 180 days), in order to study the myenteric plexus of the excluded segments. Seven non-operated rats were employed as control. The myenteric plexus was subsequently evaluated with the NADH and NADPH histochemical techniques. The colonic area of excluded segments is significantly decreased. The density of NADH-stained neurons continuously increases during the entire postoperative period but does not match the extent of surface reduction. Neuronal area measurements suggest hypertrophy of the remaining neurons in the late postoperative period. Morphological alterations of myenteric ganglia and neurons were also evident. An important surface area reduction combined with slight density increase points toward significant neuronal loss after fecal diversion. While studies correlating neuronal loss and functional changes are still lacking, surgeons should bear in mind the modifications of the myenteric plexus when performing fecal stream diversion surgeries.
Departamento de Anatomia, Laboratorio de Sistema Nervoso Autonomo, Instituto de Ciencias Biomedicas III, Av. Prof. Lineu Prestes 2415, CEP 05508-900, Cidade Universitaria, Sao Paulo, SP, Brazil. rbvfontes@yahoo.com.br
Ricardo Braganca de Vasconcellos
RB
Fontes
Luis Bernardo
LB
Froes
Erick Dancuart
ED
Omar
Edson Aparecido
EA
Liberti
D000704:Analysis of Variance; D000818:Animals; D002452:Cell Count / Q000379:methods; D003106:Colon / Q000378:metabolism / Q000601:surgery*; D003125:Colostomy / Q000379:methods; D006651:Histocytochemistry / Q000379:methods; D008297:Male; D009197:Myenteric Plexus / Q000166:cytology* / Q000378:metabolism; D009243:NAD / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D009474:Neurons / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
D009243:NAD; D009249:NADP