Number and size of myenteric neurons of the duodenum of adult rats with acute diabetes

Abstract

-This study had as its purpose to assess the effects of acute diabetes induced by streptozotocin (35 mg/kg body weight) on the number and size of the myenteric neurons of the duodenum of adult rats considering equally the antimesenteric and intermediate regions of the intestinal circumference. Experimental period extended for a week. Neuronal counts were carried out on the same number of fields of both regions of the duodenal circumference and measurements of neuronal and nuclear areas on equal numbers of cells. Number and size of the myenteric neurons stained with Giemsa were not significantly different between groups. On the other hand, the proportion of NADH-positive neurons increased from 18.54% on the controls to 39.33% on the diabetics. The authors discuss that this increased reactivity probably results from a greater NADH/NAD + ratio, described in many tissues of diabetic animals, which has consequences on the modulation of the enzymes that use these cofactors and whose activity is detected by the NADH-diaphorase technique.KEY WORDS: duodenum, myenteric neurons, acute diabetes, NADH-diaphorase.Número e tamanho dos neurônios mientéricos do duodeno de ratos adultos com diabetes agudo RESUMO -Este estudo teve como objetivo avaliar os efeitos do diabetes agudo induzido por estreptozootocina (35 mg/kg de peso corporal) sobre o número e tamanho dos neurônios mientéricos do duodeno de ratos adultos considerando de forma equivalente as regiões antimesentérica e intermediária da circunferência intestinal. O período experimental se estendeu por uma semana. As contagens neuronais foram feitas em igual número de campos nas duas regiões da circunferência duodenal e as mensurações das áreas neuronais e nucleares em igual número de células. O número e o tamanho dos neurônios corados por Giemsa não foram significativamente diferentes entre os grupos. Por outro lado, a proporção de neurônios NADH-positivos aumentou de 18,54% nos animais controles para 39,33% nos diabéticos. Os autores discutem que essa maior reatividade possivelmente resultou do aumento da proporção NADH/NAD + , descrita em diversos tecidos de animais diabéticos, que repercute na modulação das enzimas que utilizam esses cofatores e cuja atividade é detectada pela técnica da NADHdiaforase. PALAVRAS-CHAVE: duodeno, neurônios mientéricos, diabetes agudo, NADH-diaforaseThe knowledge about the mammalian enteric nervous system (ENS) can be considered, currently, as wide and in some instances, quite deep. Descriptions found on the literature assess several aspects of this subdivision of the autonomic nervous system 1-5 and reveal the richness of structure and organization of this neuronal population of magnitude similar to that of the spinal Trabalho

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

“…On the other hand, the technique of the NADH-d stains only a fraction of the myenteric neuronal population. Although there are reports that it stains almost all the myenteric neurons 27,31 , this has not been the case in our research group 14,28 . In this study, the number of NADH-d positive neurons in the proximal colon was of 57-66% that found with Giemsa.…”

“…Alternatively, neuronal activity could only be reduced to the point that the neurons did not stain after 45 minutes. In the duodenum, on the other hand, there was an increase in the NADH-d positive neuronal population in conditions of acute diabetes 14 . This shows that the NADH-d positive neurons react differently from the general neuronal population to the diabetic condition and that the location of the myenteric neurons in the bowel length influences how they react to modifications in their environment 4,7 .…”

“…Recently, we described an increase in the NADHdiaphorase positive myenteric neuronal population in the duodenum of rats subjected to acute diabetes, although the total number of neurons was not affected 14 . Aiming at evaluating the response of the neurons of the proximal colon to this same condition, we subjected adult rats to streptozotocin-induced diabetes for a period of seven days.…”

Effects of ascorbic acid supplementation in ileum myenteric neurons of streptozotocin-induced diabetic rats

“…A decrease in the number of myenteric neurons in STZ-induced diabetes in rats was observed in the stomach (Fregonesi et al 2001, Clebis et al 2004, in the duodenum (Romano et al 1996, Buttow et al 1997, Furlan et al 1999, in the ileum (Zanoni et al 2003, Alves et al 2006, in the small intestine as a whole (Hernandes et al 2000), in the cecum (Zanoni et al 2007), in the proximal colon (Furlan et al 2002). We can justify the controversial results for the NADPH-dp neurons in Group D, C, CS and DS when compared to other reports: the diabetes maintenance period as well as the neurochemical phenotype of the stained neurons was not similar.…”

Características estruturais e estereológicas do plexo cardíaco de camundongos expostos à poluição ambiental

“…Na presente pesquisa foi possível detectar dois tipos Quando se avalia, na literatura, a disposição dos gânglios do plexo cardíaco, observa-se que uma série de trabalhos faz referência à sua distribuição sem, contudo, realizarem mensurações morfométricas (Pardini et al, 1987;Wallis et al, 1996;Singh et al, 1996;De Souza et al, 1996;Batulevicus et al,2003;Maifrino et al,2006;Gama et al,2010 (Wallis et al, 1996;Armour et al, 1997;Batulevicus et al, 2003;Jurgaitiené et al, 2004), enquanto que os pesquisadores que utilizaram contagem de preparados de membrana descrevem uma menor quantidade dessas células (De Souza et al, 1996 (NADH e AChE Histoquímica); Maifrino et al, 2006 (NADPH-diaphorase); Gama et al, 2010 (β-NADH diaphorase); Rysevaite et al, 2011 (Acetyltransferase -ChAT , 1997;Furlan et al, 1999;Miranda-Neto et al, 2000).…”