Morphometry of submucous and myenteric esophagic plexus of dogs experimentally reinfected with Trypanosoma cruzi

We carried out a morphometric study of the esophagus of cross-bred dogs exp erimentally infected or consecutively reinfected with Trypanosoma cruzi 147 and SC-1 strains, in order to verify denervation and/or neuronal hypertrop hy in the intramural plexus. The animals were sacrificed in the chronic sta ge, 38 months after the initial infection. Neither nests of amastigotes, no r myositis or ganglionitis. were observed in all third inferior portions of esophageal rings analyzed. No nerve cell was identified in the submucous o f this organ. There was no significant difference (p>0.05) between the numb er, maximum diameter, perimeter, or area and volume of the the nerve cells of the myenteric plexus of infected and/or reinfected dogs and of the non-i nfected ones. In view of these results we may conclude that the 147 and SC- 1 strains have little neurotropism and do not determine denervation and/or hypertrophy in the intramural esophageal plexuses in the animals studied, i ndependent of the reinfections.