ABSTRACT
We carried out this work with the purpose of studying the effects of protein and vitamin B deficiency on the morphologic and quantitative aspects of the myenteric plexus of the descending colon of adult Rattus norvegicus. Twenty-eight rats were divided in two groups, one of them receiving chow with 22 percent protein level (control) and the other fed with chow having 8 percent protein level without vitamin B supplementation, during 120 days. Whole-mounts of the descending colon were prepared and stained with Giemsa, NADH-diaphorase and NADPH-diaphorase. The undernourished rats had a body weight 11.84 percent less than the control group. Relative to the controls, the experimental group had a colonic area 48 percent smaller, 51.9 percent less Giemsa-stained neurons, 28.3 percent less NADH-diaphorase positive neurons and 24.2 percent less NADPH-diaphorase positive neurons