Neurônios NADH-diaforase positivos do jejuno de ratos adultos (Rattus norvegicus) desnutridos: aspectos quantitativos

Abstract

RESUMO -Temos por objetivo contribuir com informações sobre os aspectos quantitativos dos neurônios mioentéricos NADH-diaforase positivos do jejuno de ratos submetidos a desnutrição protéica. Foram utilizados 10 ratos (90 dias de idade), divididos em grupos: controle (n=5, ±278g) e desnutrido (n=5, ±280g). Nos 120 dias seguintes, os ratos do grupo controle receberam ração com teor protéico de 22%, os do grupo desnutrido, 8%. Ao final deste período, os ratos do grupo controle pesaram ±394,4g e os desnutrido ±273,5g.O jejuno foi submetido à técnica histoquímica da NADH-diaforase para evidenciação de células nervosas em preparado de membranas. Foram contados os neurônios presentes em 80 campos microscópicos em ambos os grupos. Verificaram-se no controle ±674,6 neurônios e no desnutrido ±1326,8 neurônios; A dieta não alterou a organização dos neurônios entretanto, levou a um menor desenvolvimento corporal nos animais desnutridos, contribuindo para que os neurônios destes sofressem menor dispersão e apresentassem maior densidade por mm 2 . PALAVRAS-CHAVE: desnutrição, jejuno, neurônios mioentéricos, rato. NADH-diaphorase positive neurons of the jejunum of disnurtured adult rats (Rattus norvegicus): quantitative aspectsABSTRACT -We aim at contributing with information on the quantitative aspects of the NADH-diaphorase positive myenteric neurons of the jejunum of adult rats subjected to protein desnutrition. Ten rats aging 90 days were divided into two groups: control (n=5, ±278 g) and disnurtured (n=5, ±280 g). In the following 120 days, the rats from the control group had chow with 22% protein level, and those from the disnurtured group, with 8% protein level. After this period, the control rats weighted ±394.4g and the disnurtured ±273.5g. The jejunum was subjected to the histochemical technique of the NADH-diaphorase to stain nerve cells in whole-mounts. The neurons found in 80 microscopic fields of both groups were counted. In the control ±674.6 neurons were observed, and ±1326.8 neurons were counted in the disnurtured group. The low-protein diet did not alter the organization of the neurons, but led to a smaller body growth in the disnurtured animals, preventing neuronal dispersal and leading to a greater density per mm 2 .

Quantitative analysis of the neurons from the myenteric plexus in the ileum of rats submitted to severe protein deficiency

“…As the neurons present the highest metabolic activity 23 , protein reduction seemed to have activated neuronal metabolism in this study. rats submitted to 8% protein malnutrition for 120 days have also presented an increase with respect to this neuronal subpopulation in the duodenum 12 and 96.7% higher in the jejunum 13 . on the other hand, long-term diet restriction demonstrated that positive NADH-diaphorase subpopulation in the ileum decreased for the 24-month-old animals without reducing total population.…”

“…studies with different experimental models of malnutrition carried out with rats with different ages also demonstrated retarded body weight gain for the animals while fed with a 8% hypoprotein diet 6,8,9,10,13 . Body weight reduction was probably a result of the adaptation to the protein malnutrition due to lower nutrient availability, as well as lower development of fat and lean mass in these animals.…”

“…Malnutrition does not increase the number of total neurons as it is determined since the embryonic life, therefore, the neurons which were not from this class started to do it after malnutrition 13 . subpopulation of positive NADH-d neurons on CG was 35.85% of the total neuronal population and 40.53% on the EG.…”

“…Hypoplasia and hypotrophy of the mucosa in malnourished rats 6,7 and the increase of the myenteric neuronal density while reducing the protein level on the chow to 8% 6,[8][9][10][11][12][13] . As there is a gap in the literature with respect to the effects of severe malnutrition (4%) on the enteric neurons, this paper analyzed the neuronal density of the neurons from the myenteric plexus in the ileum of malnourished rats subjected to a hypoproteic diet (4%) for 90 days.…”

Efeitos da ração autoclavada sobre os aspectos quantitativos e morfométricos dos neurônios mioentéricos do jejuno de ratos em períodos de pré e pós-desmame

“…Este fato é contrário aos apresentados por trabalhos em que os animais foram submetidos à desnutrição protéica, geral ou associada (ARAÚJO et al, 2003a;CASTELUCCI et al, 2002;MELLO, STABILLE;MIRANDA NETO et al, 1999;MIRANDA, 1996;SANT'ANA et al, 1997;ZANIN et al, 2003), onde há uma queda percentual significativa no peso corpóreo.…”