Effects of protein and vitamin B deficiency on blood parameters and myenteric neurons of the colon of rats

Abstract

-The aims of this work were to evaluate the effects of the deficient ingestion of protein and vitamin B on the biochemical and hematologic parameters and on the NADH-and NADPH-diaphorase positive myenteric neurons. The control animals (n=10) received commercial chow and the experimental rats (n=10) received chow with protein level reduced to 8% during 120 days. At the time of killing blood was collected for assessment of the blood and hematologic parameters and the ascending colon for quantitative analysis of the neurons of the myenteric plexus. It was observed that the reduction of the protein level to 8% coupled to the reduction of the levels of vitamin B in adult rats neither led to qualitative or quantitative changes on red or white blood cells, nor decreased globulin levels, induced the formation of edema or gave rise to clinical signs typical of protein or vitamin B deficiency. On the other hand, the experimental protocol led to less weight gain, change on the body composition with fat deposition; decrease of the values of serum total protein and albumin; reduction of the area of colon and density of nitrergic and NADH-diaphorase myenteric neurons inferior to the expected.KEY WORDS: enteric neurons, proteic desnutrition, ascending colon, hematology, vitamin B.Efeitos da deficiência de proteínas e vitamina B sobre parâmetros sanguíneos e neurônios mioentéricos do colo de ratos adultos RESUMO -Os objetivos deste trabalho foram avaliar as repercussões da ingestão deficiente de proteínas e vitaminas do complexo B sobre parâmetros bioquímicos e hematológicos e neurônios mientéricos NADH e NADPH-diaforase positivos. Os animais controle (n=10) receberam ração comercial e os animais experimentais (n=10) ração com teor protéico reduzido para 8% durante 120 dias. Durante o sacrifício, coletou-se o sangue dos animais para avaliação de parâmetros sanguíneos e hematológicos e o colo ascendente para a análise quantitativa dos neurônios do plexo mioentérico. Observou-se que a redução do teor de proteínas na dieta para 8% associado a redução no teor de vitaminas do complexo B em ratos adultos, não causa alterações qualitativas e quantitativas das células sanguíneas das séries vermelha e branca, não leva a redução do valor da globulina nem a formação de edema ou ao surgimento de sinais clínicos característicos das carências de proteínas e vitaminas do complexo B. Por outro lado causa: menor ganho de peso corporal; alteração da composição corporal com acúmulo de gordura; redução nos valores de proteína total e albumina; redução na área do colo e evidenciação de densidade de neurônios nitrérgicos e NADH-diaforase positivos inferior ao esperado.PALAVRAS CHAVE: neurônios entéricos, desnutrição protéica, colo ascendente, hematologia, vitamina B. The utilization of animal models in studies of food restriction with known and controlled diets has as an advantage the improved knowledge about the many aspects of the human desnutrition 1 . Research on desnutrition aimsat simulating natural conditions, which involve deficienc...

Morphoquantitative effects of acute diabetes on the myenteric neurons of the proximal colon of adult rats

“…This decrease can probably be explained by the smaller body weight of the diabetic animals, which was accompanied, although not proportionately, by a diminishment of the internal organs: in percentual terms, the diabetics had a body weight loss of 16.10% relative to their initial weight, while the colon showed a weight decrease of 13.45% as compared to that of the controls. Smaller intestinal segments were frequently observed in our laboratory, specially in animals losing weight due to protein desnutrition 22,23 . Insulin deficiency is also an explanation for the reduced dimensions observed here, once insulin is an anabolic hormone and, as such, a promoter of cellular development.…”

Effect of protein and vitamin B deficiency on the morpho-quantitative aspects of the myenteric plexus of the descending colon of adult rats

“…The diet of the experimental group was obtained reducing the protein levels of the NUVILAB chow through the addition of corn starch and mixture of mineral salts, but without vitamin supplementation 14,15 . This procedure was based on models described elsewhere 1,5,6,12,21,22 .…”

“…In the same segment of adult rats subjected to protein and vitamin deficiency, it was observed a greater reduction in the total number of myenteric neurons 14,15 .…”

“…In what concerns the effects of undernourished on the myenteric plexus, the hypoproteic diet leads to a greater concentration of neurons 5,10-12 and diminishment of their numbers [13][14][15] . Nevertheless, most of the studies on the effects of malnutrition on the enteric neurons assess the small intestine 5,8,10,13,16 , the number of works dealing with the large intestine being reduced 1,11,12,14,15,17 .…”

“…Nevertheless, most of the studies on the effects of malnutrition on the enteric neurons assess the small intestine 5,8,10,13,16 , the number of works dealing with the large intestine being reduced 1,11,12,14,15,17 . Studies in the ascending colon of rats subjected to protein deficiency during gestation and lactation demonstrated increased neuronal density and incidence of large neurons 11 , while animals subjected to apoproteic diet during gestation and lactation had changes in the myenteric ganglia shape, reduction in the area of the neuronal profile and greater density of the neurons in the total colon 17 .…”