Summary This report aims to study architectural Auerbach ple- xus structure with NADH histochemistry (nicotinami- de adenine dinucleotide, reduced form), along ages and their modifications with restricted diet in obese β line rats. Experimental groups were: 1) After weaning, male rats were fed ad libitum (ALD) with standard rat chow. Autopsies were done at 2, 4, 8, 12, and 18 months old. 2) After weaning, one group was fed ad li- bitum, another group of rats were maintained on a res- tricted diet (RD). Autopsy was performed at 8 months of age. 3) After weaning, male rats were fed ad libi- tum (ALD) with standard rat chow. At 60 days old one group was continued with standard rat chow. Another group was fed with a restricted diet (RD). Au- topsy was performed at 120 days old. After autopsy, segments of small intestine, proximal and distal colon were processed for NADH histochemistry. 1) At 2 months of age some empty spaces ("neuronal ghosts") were seen between neurons. Later on partial to total disruption of reticular structures was seen along ages. 2) In RD rats of 8 months of age, a mesh-like structu- re similar to normal control rats was observed. In ALD rats, partial to total disruption of mesh-like structures was seen. 3) In RD rats of 4 months of age, disruption intermingled with normal mesh-like zones was seen, more severe in ALD rats. Changes in Auer- bach plexus structure (disruption of mesh-like appea- rance) in this line of rats were quite different from nor- mal control rats suggesting dismetabolism effects. Die- tary restriction delayed alterations in Auerbach plexus structures in obese rats. Key words. obesity, myenteric plexus, diabetes, small intestine, colon. Estructura del plexo de Auerbach con técnica histoquímica del NADH en una línea de ratas obesas: efectos de la restricción dietaria Resumen Estudiamos las modificaciones con la edad y con una dieta restrictiva de la estructura reticulada del plexo de Auerbach en ratas β (obesas) en intestino delgado, colon proximal y distal que fueron procesados con la técnica histoquímica de NADH (nicotinamide adeni- ne dinucleotide, reduced form). Los grupos experimen- tales fueron: 1) Después del destete ratas machos fueron alimentadas ad libitum (DAL) con dieta balanceada comercial y autopsiados a los 2, 4, 8, 12 y 18 meses de edad. A los 2 meses de edad se observaron espacios va- cíos interneuronales y a edades mayores mostraron una destrucción parcial a total de la estructura reticular. 2) Después del destete un grupo fue alimentado con DAL y otro con dieta restringida (RD). Se realizó la autop- sia a los 8 meses de edad. En los animales con RD de 8 meses de edad se pudo observan una estructura nor- mal reticulada muy similar a otras ratas controles. En las ratas con DAL se observó una ruptura parcial y/o total de la estructura reticulada. 3) Después del deste- te, las ratas fueron mantenidos con DAL hasta los 60 días de edad en que un grupo siguió con DAL y otro con RD. La autopsia se hizo a los 120 días. Se obser- varon zonas con una destrucción parcial de la estruc- tura reticulada que se entremezclaron con zonas con- Correspondence: Noriyuki Hisano Department of Histology & Embryology, School of Medical Sciences, National University of Rosario. Santa Fe 3100 S 2002 KTQ. Rosario, Argentina E-mail: norihisano@yahoo.com.ar Auerbach plexus structure with NADH histochemistry in a line of obese rats: effects of dietary restriction Silvia M Vázquez, 1 Marta Posadas, 2 Verónica B Labourdette, 2 María del Carmen Gayol, 2 Noriyuki Hisano 1 1 Department of Histology & Embryology, School of Medical Sciences, National University of Rosario. Rosario. Argentina. 2 Department of Biology, School of Medical Sciences, National University of Rosario. Rosario. Argentina. Acta Gastroenterol Latinoam 2010;40:251-257 ◆ MANUSCRITO ORIGINAL 251  Acta Gastroenterológica Latinoamericana – Vol 40 / N° 3 / Septiembre 2010 VAZQUEZ 9/14/10 11:43 AM Página 251