-The effects of acute diabetes on the density and size of the myenteric neurons of the proximal colon of adult rats were investigated. The injection of streptozotocin was followed by a period of observation of seven days, during which the diabetic animals showed weight loss, excessive food and water intake, large urinary debt and hyperglicemia. The whole-mounts from the proximal colon were stained with the techniques of Giemsa and of the NADH-diaphorase, and the employment of these techniques made it possible to verify a decrease on the neuronal density and on the cell body size of the myenteric neurons in the colon of the diabetic rats. These observations were discussed in terms of the pathophysiology of the diabetes and the experimental protocol.KEY WORDS: acute diabetes, myenteric neurons, proximal colon.Efeitos morfoquantitativos do diabetes agudo sobre os neurônios mioentéricos do colo proximal de ratos adultos Efeitos morfoquantitativos do diabetes agudo sobre os neurônios mioentéricos do colo proximal de ratos adultos Efeitos morfoquantitativos do diabetes agudo sobre os neurônios mioentéricos do colo proximal de ratos adultos Efeitos morfoquantitativos do diabetes agudo sobre os neurônios mioentéricos do colo proximal de ratos adultos Efeitos morfoquantitativos do diabetes agudo sobre os neurônios mioentéricos do colo proximal de ratos adultos RESUMO -Foram investigados os efeitos do diabetes agudo sobre a densidade e o tamanho dos neurônios mioentéricos do colo proximal de ratos adultos. À injeção de estreptozootocina seguiu-se um período de observação de sete dias, durante os quais os animais diabéticos apresentaram perda de peso, ingestão excessiva de alimento e água, grande débito urinário e hiperglicemia. Os preparados de membrana do colo proximal foram corados pelas técnicas de Giemsa e da NADH-diaforase. A aplicação dessas técnicas permitiu constatar uma redução da densidade neuronal e do tamanho do corpo celular dos neurônios mioentéricos no colo dos ratos diabéticos. Essas observações foram discutidas em termos da patofisiologia do diabetes e do protocolo experimental. The research on the changes induced by experimental diabetes on the several tissues and organs of laboratory animals is quite large. Among those systems under investigation are the gastrointestinal tract and its intrinsic enteric nervous system, the neuronal network responsible for the control of the activities of the bowel. It is reported, for instance, that the myenteric neurons of the stomach, duodenum and cecum are numerically reduced in diabetes 1-3 , and that specific neurochemical groups show response patterns to diabetes which depend on the intestinal segment and the duration of the diabetic state 4-7 . These neuronal changes, as well as those associated to the autonomic innervation of the gut 8-10 , stand among the responsible by the clinical gastrointestinal symptoms of diabetes [11][12][13] . PALAVRAS-CHAVERecently, we described an increase in the NADHdiaphorase positive myenteric neuronal population in the duo...

The purpose of this work was to study the area of the varicosities of nerve fibers of myenteric neurons immunoreactive to vasoactive intestinal peptide (VIP-IR) and of the cell bodies of VIP-IR submucosal neurons of the jejunum of diabetic rats supplemented with 2% L-glutamine. Twenty male rats were divided into the following groups: normoglycemic (N), normoglycemic supplemented with L-glutamine (NG), diabetic (D) and diabetic supplemented with L-glutamine (DG). Whole-mounts of the muscle tunica and the submucosal layer were subjected to the immunohistochemical technique for neurotransmitter VIP identification. Morphometric analyses were carried out in 500 VIP-IR cell bodies of submucosal neurons and 2000 VIP-IR varicosities from each group. L-Glutamine supplementation to the normoglycemic animals caused an increase in the areas of the cell bodies (8.49%) and varicosities (21.3%) relative to the controls (P < 0.05). On the other hand, there was a decrease in the areas of the cell bodies (4.55%) and varicosities (28.9%) of group DG compared to those of group D (P < 0.05). It is concluded that L-glutamine supplementation was positive both to normoglycemic and diabetic animals.

-The aim of this study was to evaluate the effect of the ascorbic acid (AA) supplementation on the neurons that produce the vasoactive intestinal peptide (VIP) in the submucous plexus of the ileum of rat, four months after the induction of experimental diabetes mellitus with streptozotocin. Three groups of rats were used: C -control, D -diabetic, DA -diabetic receiving AA. We have measured the immunoreactivity and area of 80 cellular bodies of VIP-ergic neurons from each studied group. In the diabetic animals, we have observed hyperphagia, polydipsia, and an increase of glycemia and glycated hemoglobin. The VIP-ergic neurons have presented an increase of their immunoreactivity and the highest profiles when compared to the other groups. In the diabetic animals supplemented with AA it has been observed a small reduction in the glycemia and the water and food intake. We have also noticed smaller immunoreactivity in their VIP-ergic neurons, similar to what we have observed in the control group animals (group C).KEY WORDS: ascorbic acid, diabetes mellitus, streptozotocin, ileum, vasoactive intestinal peptide, submucous plexus, rats.Plexo submucoso de íleo terminal: estudo dos neurônios VIP Plexo submucoso de íleo terminal: estudo dos neurônios VIP Plexo submucoso de íleo terminal: estudo dos neurônios VIP Plexo submucoso de íleo terminal: estudo dos neurônios VIP Plexo submucoso de íleo terminal: estudo dos neurônios VIP-érgicos de ratos diabéticos tratados com -érgicos de ratos diabéticos tratados com -érgicos de ratos diabéticos tratados com -érgicos de ratos diabéticos tratados com -érgicos de ratos diabéticos tratados com ácido ascórbico ácido ascórbico ácido ascórbico ácido ascórbico ácido ascórbico RESUMO -O objetivo deste estudo foi avaliar o efeito da suplementação com ácido ascórbico (AA) sobre os neurônios que expressam o peptídeo intestinal vasoativo (VIP) no plexo submucoso do íleo de ratos, quatro meses após a indução do diabetes mellitus experimental com estreptozootocina. Três grupos de ratos foram usados: C-controles, D-diabéticos, DA-diabéticos recebendo AA. Foram avaliadas a imunoreatividade e a área de 80 corpos celulares de neurônios VIP-érgicos de cada grupo estudado. Nos animais diabéticos ocorreram hirperfagia, polidipsia, elevação da glicemia e hemoglobina glicada. Os neurônios VIP-érgicos apresentaram aumento da imunorreatividade e os maiores perfis, quando comparados aos demais grupos. Nos animais diabéticos suplementados com AA observou-se pequena redução na glicemia, ingesta de água e de alimento, verificando-se também menor imunorreatividade nos neurônios VIP-érgicos, o que foi semelhante ao observado nos animais do grupo controle (grupo C). PALAVRAS-CHAVE: acido ascórbico, diabetes mellitus, estreptozootocina, íleo, peptídeo intestinal vasoativo, plexo submucoso, ratos.

Neotropical Entomology 35(1): 070-074 (2006) Citopatologia Causada Pelo Nucleopolyhedrovirus em Células do Sistema Nervoso Central de Bombyx mori (L.) (Lepidoptera: Bombycidae) RESUMO PALAVRAS-CHAVE: Insecta, bicho-da-seda, Baculoviridae, lamela neural, perineuro ABSTRACT -BmMNPV, a Nucleopolyhedrovirus isolated from infected Bombyx mori (L.) larvae in Paraná State -Brazil, was used to inoculate healthy 5 th -instar B. mori larvae and examine the infection on central nervous system (CNS) cells. Samples of nervous tissue were removed from the infected insects, at different sampling times, and processed for cytopathology studies by light and transmission electron microscopy using routine techniques. The experiment included both inoculated and noninoculated larvae (control). BmMNPV infection was detected on the 5th day after inoculation in CNS cells. Initially, infection was characterized by nuclear hypertrophy and the presence of virogenic stroma, in which the progeny virions were produced. Virions are enveloped and occluded into protein crystal, the polyhedra. Lyses of infected CNS cells were undetected; however, free mature polyhedra were seen in spaces inside the CNS. These polyhedra possibly came from trachea that penetrate the CNS and its cells, which are susceptible to BmMNPV and lyses after infection. We conclude that the tracheal system is responsible for disseminating BmMNPV infection in B. mori CNS and that the tracheal branches allow non-occluded virions to pass through the blood-brain barrier.

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% protein level (control) and the other fed with chow having 8% 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% less than the control group. Relative to the controls, the experimental group had a colonic area 48% smaller, 51.9% less Giemsa-stained neurons, 28.3% less NADH-diaphorase positive neurons and 24.2% less NADPH-diaphorase positive neurons.

We investigated the effect of ascorbic acid (AA) supplementation on the NADPH-diaphorase (NADPHd) and myosin-V myenteric neurons in the ileum of rats, after 4 months of treatment. Two groups were compared, i.e. controls rats (C) and AA-treated rats (CA). Myosin-V immunohistochemistry and NADPHd histochemistry were employed. We investigated the areas of 500 cell bodies of myosin-V neurons and of 500 NADPHd stained neurons from all groups. The quantitative analysis was performed using an area of 8.96 mm2 from each ileum. There was an increase of 21.9% in the myosin-V immunoreactive myenteric neurons (P > 0.05) and of 22.5% in the NADPHd in group CA when compared with C (P < 0.05). There were no significant differences when we compared the area of myosin-V stained neurons between groups C and CA. However, we verified an area reduction of 7.5% in NADPHd neurons when comparing group C to group CA (P < 0.05).

PurposeEnteric glial cells (EGCs) exert a critical role in the structural integrity, defense, and metabolic function of enteric neurons. Diabetes mellitus is a chronic disease characterized by metabolic disorders and chronic autonomic neuropathy. Quercetin supplementation, which is a potent antioxidant, has been used in order to reduce the effects of diabetes-induced oxidative stress. The purpose of this research was to investigate the effects of quercetin supplementation in the drinking water at a daily dose of 40 mg on the glial cells and neurons in the jejunum of diabetic rats.Materials and methodsTwenty 90-day-old male adult Wistar rats were split into four groups: normoglycemic control (C), normoglycemic control supplemented with quercetin (Q), diabetic (D), and diabetic supplemented with quercetin (DQ). After 120 days, the jejunums were collected, and immunohistochemical technique was performed to label S-100-immunoreactive glial cells and HuC/D-immunoreactive neurons.ResultsAn intense neuronal and glial reduction was observed in the jejunum of diabetic rats. Quercetin displayed neuroprotective effects due to reduced cell body areas of neurons and glial cells in Q and DQ groups compared to their controls (C and D groups). Interestingly, quercetin prevented the glial and neuronal loss with a higher density for the HuC/D-immunoreactive neurons (23.06%) and for the S100-immunoreactive glial cells (14.55%) in DQ group compared to D group.ConclusionQuercetin supplementation promoted neuroprotective effects through the reduction of neuronal and glial body areas and a slight prevention of neuronal and glial density reduction.

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