Evaluation of serum ghrelin, nesfatin-1, irisin, and vasoactive intestinal peptide levels in temporal lobe epilepsy patients with and without drug resistance: a cross-sectional study

SUMMARY OBJECTIVE: Epilepsy is a common disorder that affects the nervous systems of 1% of worldwide population. In epilepsy, one-third of patients are unresponsive to current drug therapies and develop drug-resistant epilepsy. Alterations in ghrelin, nesfatin-1, and irisin levels with epilepsy were reported in previous studies. Vasoactive intestinal peptide is among the most common neuropeptides in the hippocampus, which is the focus of the seizures in temporal lobe epilepsy. However, there is also lack of evidence of whether these four neuropeptide levels are altered with drug resistant temporal lobe epilepsy or not. The aim herein was the evaluation of the serum levels of nesfatin-1, ghrelin, irisin, and Vasoactive intestinal peptide in drug-resistant temporal lobe epilepsy patients and temporal lobe epilepsy (TLE) without drug resistance, and to compare them to healthy controls. METHODS: This cross-sectional study group included 58 temporal lobe epilepsy patients (24 with drug resistant temporal lobe epilepsy and 34 with temporal lobe epilepsy who were not drug-resistant) and 28 healthy subjects. Nesfatin-1, ghrelin, irisin, and Vasoactive intestinal peptide serum levels were determined using enzyme-linked immunosorbent assay. RESULTS: The serum ghrelin levels of patients with drug resistant temporal lobe epilepsy were seen to have significantly decreased when compared to those of the control group (p<0.05). Serum nesfatin-1, vasoactive intestinal peptide, and irisin levels were seen to have decreased in the drug resistant temporal lobe epilepsy group when compared to those of the control and temporal lobe epilepsy groups; however, the difference was non-significant (p>0.05). CONCLUSIONS: The results herein suggested that ghrelin might contribute to the pathophysiology of drug resistant temporal lobe epilepsy. However, further studies are needed to confirm this hypothesis.

Modulatory effects of neuropeptides on pentylenetetrazol-induced epileptic seizures and neuroinflammation in rats

SUMMARY OBJECTIVE We aimed to explore the effects of neuropeptides ghrelin, obestatin, and vasoactive intestinal peptide (VIP) on seizures and plasma concentrations of neuroinflammation biomarkers including calcitonin gene-related peptide (CGRP), substance-P (SP), and interleukin-1 beta (IL-1β) in pentylenetetrazol-induced seizures in rats. METHODS Ghrelin (80 µg/kg), obestatin (1 µg/kg), VIP (25 ng/kg) or saline were administered to rats intraperitoneally 30 min before pentylenetetrazole (PTZ, 50 mg/kg) injections. Stages of epileptic seizures were evaluated by Racine's scale, and plasma CGRP, SP, and IL-1β concentrations were measured using ELISA. RESULTS Both obestatin and VIP shortened onset-time of generalized tonic-clonic seizure, respectively, moreover VIP also shortened the onset-time of first myoclonic-jerk induced by PTZ. While PTZ increased plasma CGRP, SP and IL-1β concentrations, ghrelin reduced the increases evoked by PTZ. While VIP further increased PTZ-evoked CGRP levels, it diminished IL-1β concentrations. However, obestatin did not change CGRP, SP, and IL-1β concentrations. CONCLUSION Our results suggest that ghrelin acts as an anticonvulsant, obestatin acts as a proconvulsant, and VIP has dual action on epilepsy. Receptors of those neuropeptides may be promising targets for epilepsy treatment.

RESUMO OBJETIVO Nosso objetivo foi explorar os efeitos dos neuropeptídeos grelina, obestatina e peptídeo intestinal vasoativo (VIP) nas convulsões e concentrações plasmáticas de biomarcadores neuroinflamatórios, incluindo peptídeo relacionado ao gene da calcitonina (CGRP), substância-P (SP) e interleucina-1 beta (IL-1β) em convulsões induzidas por pentilenotetrazol em ratos. MÉTODOS Grelina (80 µg/kg), obestatina (1 µg/kg), VIP (25 ng/kg) ou solução salina foram administrados a ratos intraperitonealmente 30 minutos antes de injeções de pentilenotetrazol (PTZ, 50 mg/kg). Os estágios das crises epilépticas foram avaliados pela escala de Racine e as concentrações plasmáticas de CGRP, SP e IL-1β foram medidas usando Elisa. RESULTADOS Tanto a obestatina quanto o VIP encurtaram o tempo de início da crise tônico-clônica generalizada, respectivamente. Além disso, o VIP também encurtou o tempo de início do primeiro impulso mioclônico induzido por PTZ. Enquanto o PTZ aumentou as concentrações plasmáticas de CGRP, SP e IL-1β, a grelina reduziu os aumentos evocados por PTZ. Enquanto o VIP aumenta ainda mais os níveis de CGRP evocados por PTZ, diminui as concentrações de IL-1β. No entanto, a obestatina não alterou as concentrações de CGRP, SP e IL-1β. CONCLUSÃO Nossos resultados sugerem que a grelina tem anticonvulsivante, a obestatina tem proconvulsivante e o VIP tem ação dupla na epilepsia. Receptores desses neuropeptídeos podem ser alvos promissores para o tratamento da epilepsia.

Diarrea crónica como manifestación inicial de un ganglioneuroblastoma / Chronic diarrhea as the initial manifestation of a ganglioneuroblastoma

Resumen: El neuroblastoma es un tumor maligno del sistema nervioso simpático periférico con presentación y curso clínico heterogéneo. Es el tercer tumor pediátrico más frecuente y el 90% de los casos se diagnostica antes de los 5 años. Los síntomas más comunes se deben a la compresión por la masa tumoral o al dolor óseo causado por la metástasis. La diarrea como síntoma principal es rara por lo que es difícil de diagnosticar en la etapa temprana de la enfermedad. Se presenta el caso clínico de una paciente de 2 años en la que luego de 8 meses de estudio por diarrea crónica se diagnóstica ganglioneuroblastoma secretor de VIP. Se debe plantear como diagnóstico diferencial en los pacientes menores de 3 años con diarrea crónica intratable luego de haber descartado otras etiologías.

Summary: Neuroblastoma is a malignant tumor of the peripheral sympathetic nervous system with heterogeneous clinical presentation and course. It is the third most frequent pediatric tumor and in 90% of cases it is diagnosed before 5 years of age. The most typical symptoms result from the tumor compression or bone pain caused by methastasis. Diarrhea as the main symptom is unusual, and thus it is hard to diagnose in early stages of the disease. We report the case of a 2-year-old patient who, after 8 months of study for chronic diarrhea was diagnosed with VIP-secreting ganglioneuroblastoma. It is necessary for this condition to be considered as a differential diagnosis in patients younger than 3 years old with chronic diarrhea with no evolution, after other etiologies are ruled out.

Expressão de mediadores neurotróficos e pró-inflamatórios na endometriose de reto e sigmoide / Expression of neurotrophic and inflammatory mediators in rectosigmoid endometriosis

OBJETIVO: Avaliar a expressão de mediadores neurotróficos (NGF, NPY E VIP) e pró-inflamatórios (TNF-α) em fragmentos de reto e sigmoide comprometidos por endometriose. MÉTODOS: Foram selecionadas 24 pacientes submetidas ao tratamento cirúrgico de endometriose de reto e sigmoide com técnica de ressecção segmentar, seguido de anastomose mecânica término-terminal, com grampeador circular, no período de janeiro de 2005 a dezembro de 2007. Neste estudo incluímos mulheres no menacme que se submeteram a tratamento cirúrgico por endometriose profunda infiltrativa com acometimento do reto e sigmoide, atingindo o nível da camada muscular, submucosa ou mucosa. Para o grupo de estudo foram utilizados 24 fragmentos de reto e sigmoide com endometriose confirmada histologicamente, sendo um fragmento de cada uma das 24 pacientes selecionadas. Para o grupo controle, utilizou-se um fragmento da margem distal da ressecção, denominado anel de anastomose, de cada uma das 24 pacientes selecionadas e incluídas no estudo. As amostras foram agrupadas em blocos de Tissue Micro Array (TMA) e submetidas à reação imunoistoquímica para avaliar a expressão do fator de necrose tumoral alfa (TNF-α), do fator de crescimento neural (NGF), do neuropeptídeo Y (NPY) e do peptídeo intestinal vasoativo P (VIP), e posterior análise semiquantitativa da imunomarcação por meio da leitura da densidade ótica relativa (DO). RESULTADOS: Observou-se maior densidade ótica relativa da imunomarcação para TNF-α e NGF no grupo de estudo (amostras com endometriose intestinal), DO= 0,01, respectivamente, para as duas proteínas (p<0,05), em relação aos controles sem endometriose. Não houve diferença estatística na densidade ótica da imunomarcação do NPY e VIP. CONCLUSÃO: Identificou-se o aumento da imunomarcação dos anticorpos TNF-α e NGF em fragmentos de reto e sigmoide comprometidos por endometriose em relação aos controles livres da doença. Não identificamos diferença estatística na imunomarcação das proteínas NPY e VIP.

PURPOSE: To evaluate the expression of neurotrophic (NGF, NPY and VIP) and pro-inflammatory (TNF-α) mediators in the rectum and sigmoid fragments compromised by endometriosis. METHODS: Twenty-four patients were selected to undergo surgical treatment of endometriosis of the rectum and sigmoid colon with a segmental resection technique, followed by end-to-end anastomosis with a circular stapler from January 2005 to December 2007. The study included premenopausal women who underwent surgical treatment for deep endometriosis infiltrating the rectum with involvement of the rectum and sigmoid, reaching the level of the muscle layer, submucosa or mucosa. Twenty-four rectum and sigmoid fragments with histologically confirmed endometriosis, one from each of the 24 selected patients, were used for the study group. For the control group, we used a fragment of the distal resection margin called anastomosis ring from each of the 24 patients enrolled in the study. Samples were grouped into Tissue Micro Array (TMA) blocks and subjected to immunohistochemistry to evaluate the expression of tumor necrosis factor alpha (TNF-α), nerve growth factor (NGF), neuropeptide Y (NPY) and P vasoactive intestinal peptide (VIP), followed by semiquantitative analysis of immunostaining by reading the relative optical density (OD). RESULTS: There was higher optical density relative to TNF-α immunostaining and NGF in the study group (samples with intestinal endometriosis), DO=0.01, for the two proteins, respectively (p<0.05), compared to controls without endometriosis. There was no statistically significant difference in the optical density of immunostaining of NPY and VIP. CONCLUSION: We identified increased immunostaining of TNF-α antibodies and fragments of NGF in the rectum and sigmoid compromised by endometriosis compared to disease-free controls. We did not identify any statistical difference in immunostaining of NPY and VIP proteins.

VIPoma pancreático: Caso clínico / Pancreatic VIPoma: Report of one case

Neuroendocrine tumors are uncommon, including VIPoma that produces vasoactive intestinal polypeptide. We report a 45-year-old female presenting with a history of diarrhea lasting three months. An abdominal CAT scan showed a solid tumor in the body of the pancreas. A fine needle aspiration biopsy of the tumor was compatible with a neuroendocrine tumor. The patient was subjected to a partial pancreatectomy, excising a 4 cm diameter tumor. The pathological study was compatible with a neuroendocrine carcinoma. There was no regional lymph node involvement. During the postoperative period the results of serum vasoactive intestinal polypeptide were received. These were 815.9 pg/ml before surgery and normalized after the operation.

Síndrome do ceco móvel: manifestações clínicas e avaliação radiológica da mobilidade do ceco e cólon ascendente em pacientes com queixa de constipação crônica / Mobile cecum syndrome: clinical manifestations and radiologic avaliation of the mobility of cecum and ascending colon in patients with chronic constipation

A síndrome do ceco móvel é uma doença causada por um mesentério relativamente alongado do ceco e segmento do cólon ascedente podendo levar a torções as quais poderiam causar micro danos vasculares impedindo a ação plena de substâncias como o peptídeo intestinal vasoativo e do óxido nítrico, fundamentais para o correto funcionamento do trato gastrointestinal. Este estudo tem como objetivo avaliar a relação entre a mobilidade do ceco e cólon ascendente (diagnosticada por exame radiológico) e a constipação crônica. Foram estudados 40 pacientes constipados, do Ambulatório de Coloproctologia do Hospital Regional de Mato Grosso do Sul (HRMS), segundo protocolo em anexo, por meio de analise radiográfica do segmento em questão. Verificou-se que a maioria dos pacientes (72,50 por cento) apresentou mobilidade radiológica do ceco e cólon ascendente, e que as variáveis clínicas estudadas segundo o protocolo não são suficientes para definir esses pacientes como portadores dessa síndrome.

Mobile cecum syndrome is a disease caused by the failure of the right colon fusion with the lateral peritoneum. It might lead to volvulus which could cause micro vascular damages preventing the full action of substances such as the intestinal vasoactive peptide and nitric oxide. These substances are necessary to the correct gastrointestinal function. The objective of this study is to evaluate the relationship between the mobility of cecum and the right colon (diagnosed by radiological examination) and the chronic constipation. Forty constipated patients, from the Clinic of Coloproctologia of the Hospital Regional de Mato Grosso do Sul (HRMS), in accordance with the attached protocol were studied through radiological analysis. It was observed that the majority of the patients (72,50 percent) presented radiological mobility of the cecum and right colon and that the clinical variable studied according to the protocol are not enough to define these patients as mobile cecum syndrome patients.

Effects of ascorbic acid on the vasoactive intestinal peptide synthesis in the ileum submucous plexus of normal rats

RACIONAL: O envelhecimento é um processo deteriorativo que acomete o trato gastrointestinal, provocando alterações no número e tamanho dos neurônios do sistema nervoso entérico. A ação dos radicais livres nos neurônios entéricos é favorecida pela diminuição significativa de antioxidantes. OBJETIVO: Avaliar o efeito da suplementação com ácido ascórbico sobre os neurônios submucosos do íleo de ratos normais que produzem o peptídio intestinal vasoativo (VIP) por um período de 120 dias. MÉTODOS: Quinze ratos foram divididos em três grupos: controles com 90 dias, controles com 210 dias e tratados com ácido ascórbico com 210 dias. O ácido ascórbico foi administrado durante 16 semanas a partir de 90 dias de idade pela adição em água (1 g/L/dia). O íleo foi processado para obtenção de preparados totais empregados na realização de técnica imunoistoquímica para detectar a presença de corpos celulares e fibras VIP imunoreativas nos neurônios do plexo submucoso. O perfil celular e a imunoreatividade de 80 corpos celulares de neurônios VIP-érgicos de cada grupo estudado foi verificada. RESULTADOS: A suplementação com ácido ascórbico não alterou parâmetros fisiológicos tais como a água ingerida e alimento consumido nos três grupos estudados. Observou-se aumento significativo do perfil celular dos neurônios VIP-érgicos dos animais controles com 210 dias, quando comparados com os controles com 90 dias. O perfil celular dos neurônios VIP-érgicos no grupo de animais tratados com ácido ascórbico foi maior do que aqueles observados nos grupos controles. CONCLUSÃO: O ácido ascórbico teve efeito neurotrófico sobre os neurônios VIP-érgicos do íleo após 120 dias de suplementação.

Imunofluorescência para neuropeptídeos na mucosa nasal humana: avaliacão de técnica para peptídeo intestinal vasoativo (VIP) / Neuropeptide immunofluorescence in human nasal mucosa: assessment of the technique for vasoactive intestinal peptide (VIP)

Os neuropeptídeos são neurotransmissores relevantes na fisiologia nasal e o conhecimento crescente acerca de seu papel na fisiopatologia de doencas nasais abre novas perspectivas. A sua investigacão na mucosa nasal humana baseia-se em grande parte em marcacão imunológica, método complexo e sujeito a inúmeros fatores de erro. Com o intuito de viabilizar este tipo de pesquisa em nosso meio, um método de imunofluorescência para peptídeo intestinal vasoativo (VIP) na mucosa nasal humana é proposto e avaliado. FORMA DE ESTUDO: Coorte transversal. MATERIAL E MÉTODO: Oito pacientes submetidos a cirurgia funcional do nariz têm um fragmento de mucosa coletado da concha inferior. O tecido foi fixado em solucão de Zamboni (paraformaldeído 4 por cento tamponado e ácido pícrico 0,4 por cento), congelado em nitrogênio líquido e armazenado. Cortes de 14 æm foram realizados e submetidos à reacão de imunofluorescência para VIP (Península Laboratories). As imagens microscópicas foram documentadas em fotografia convencional. A especificidade, sensibilidade e reprodutibilidade de execucão foram avaliadas. A reprodutibilidade de interpretacão de resultados foi avaliada através da comparacão de graus de marcacão (0 a 4) atribuídos às fotos por seis observadores. RESULTADOS: Os resultados mostraram ser o método suficientemente específico, sensível, além de reprodutível em sua execucão. A interpretacão de resultados mostrou depender do perfeito esclarecimento do observador no julgamento das imagens de imunofluorescência, mas mostrou uniformidade. CONCLUSAO: O método proposto foi considerado útil na pesquisa de neuropeptídeos na mucosa nasal humana.

Effect of acetyl-L-carnitine on Vip-ergic neurons in the jejunum submucous plexus of diabetic rats

The effect of the treatment with acetyl-L-carnitine (ALC) on neurons releasing the vasoactive intestinal polypeptide (VIP) of the submucous plexus in the jejunum of diabetic rats was the purpose of our investigation. Diabetes (DM) was induced by injecting streptozotocin endovenously (35mg/kg). After sacrificing the animals, the jejunum was collected and processed for VIP detection. Four groups were used: C (non-diabetic), CC (non-diabetic treated with ALC), D (diabetic), DC (diabetes treated with ALC). We analyzed the immunoreactivity and the cellular profile of 126 cell bodies. The treatment with ALC improved some aspects of DM. However, it promoted a small increase in the area of neurons from group CC, suggesting a possible neurotrophic effect. Neurons from groups D and DC showed a large increase in their cellular profile and immunoreactivity when compared to C and CC, suggesting a larger concentration of this neurotransmitter within the neurons that produce it. This observation constitutes a recurrent finding in diabetic animals, suggesting that ALC doesnot interfere in the pathophysiological mechanisms that unchain a higher production and/or neurotransmitter accumulation and increase the profile of the VIP-ergic neurons

Radioiodination of vasoactive intestinal peptide (VIP) using different oxidative electrophilic substitution agents

O Peptídeo Intestinal Vasoativo (VIP) é um peptídeo linear composto de 28 aminoácidos com um amplo espectro de atividades biológicas. Várias células tumorais expressam quantidades significantes de receptores para VIP, provendo a base para o uso do peptídeo na localização de adenocarcinomas. A molécula de VIP contém dois resíduos de tirosina, nas posições 10 e 22, susceptíveis à iodação. Este trabalho descreve a influência do agente oxidante na pureza radioquímica e nas diferentes formas de VIP obtidas, analisadas por cromatografia líquida de alta eficiência (CLAE). Três procedimentos de marcação foram estudados. Nos dois primeiros foi utilizado como agente oxidante Iodogen, na forma de um fino filme, aderido ao tubo de reação bem como na forma de suspensão. As reações de iodação foram conduzidas por 30 minutos à temperatura ambiente e com agitação suave. No terceiro procedimento de marcação empregou-se Cloramina T como agente oxidante e após um curto período de incubação à temperatura ambiente e agitação suave, a reação foi interrompida pela adição de metabissulfito de sódio. A pureza radioquímica das marcações foi determinada por cromatografia líquida de alta eficiência (coluna de fase reversa C18, 5µm, 4,6 x 50 mm) com mistura de solvente composta de TFA (solução aquosa de ácido trifluoracético 0,1 por cento): acetonitrila 73:27 por cento, com fluxo de 0,5 mL/minuto. A porcentagem de radioiodo nas marcações também foi determinada por eletroforese. O peptídeo radioiodado foi produzido com alto rendimento e pureza radioquímica, em um curto período de tempo, particularmente ao utilizar-se Cloramina-T como agente oxidante. O sistema de cromatografia líquida estudado possibilitou a separação do VIP marcado com alta atividade específica, necessária para procedimentos diagnósticos que envolvem a ligação de radiofármacos a receptores específicos

La interrupción temprana del vínculo social altera la organización citoarquitectónica y expresión de neuropéptidos en la corteza prefrontal / Early disruption of social attachment alters the cytoarchitectonic organization and neuropeptide expression in the prefrontal cortex

En el presente trabajo se evalúa el efecto que produce el entorno social sobre la maduración neuronal y la expresión del péptido intestinal vasoactivo (VIP) en ratas postlactantes. Se emplearon técnicas de Golgi-Cox-Sholl e inmunocitoquímicas para evaluar el patrón de ramificación dendrítica y la expresión de VIP en animales criados en un medio social aislado (SA) versus uno social habitual (SH). Las ratas del grupo SA presentaron un menor porcentaje de dendritas basales asociado a un incremento en la expresión de VIP respecto de los animales SH. Estas alteraciones neuronales no fueron recuperadas a pesar de restituirles su entorno social durante 30 días. Los animales SA mostraron además un deterioro significativo de la conducta exploratoria. Estos hallazgos conjuntamente con antecedentes clínicos previos sugieren que el ambiente social temprano puede ocacionar cambios morfofuncionales notables en la corteza prefrontal

Terminal ileum submucous plexus: Study of the VIP-ergic neurons of diabetic rats treated with ascorbic acid

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)

Secretion from neuropeptide-treated splenocytes modifies ovarian steroidogenesis

There are evidences for modulation of immune function by the sympathetic nervous system and its principal neurotransmitter norepinephrine (NE) throgugh superior ovarian nerve (SON)-coeliac ganglionnoradrenergic postganglionic innervation of the spleen. Seven days after SON transection at 53 days of age, the rat splenocytes were isolated and then cultured for 48h. These culture media, used to simulate ovaries from 60-day- old intact rats (neither SON-transected nor sham-operated) at diestrus 2 stage, in in vitro incubations, showed adecrease in progesterone release, an increase in estradiol release and no change in androstenedione release in relation to splenocyte culture media from control (sham-operated) rats.When esplenocytes from SON transected (SON-t) rats were treated with vasoactive intestinal peptide (VIP) or neuropeptide Y (NPY), both at 16-6M for 24h, their secretions increased the progesterone release while decreasing the estradiol release from the intact ovaries, compared with the secretions of untreated splenocytes from SON-t rats. Although the secretions of splenocytes treated with VIP decrease the androstenedione release from de ovaries, the treatment with NPY produced no change in hormone release. In the present paper the ovarian steroidogenic response, which was modified by the effects of an in vivo SON transection on spleen cells, was reverted by an in vitro system in which the splenocytes were treated with VIP or NPY. This could indicate that the spleen of SON-t rats does not receive those neuropeptides by neural route however, when they are added to splenocyte culture in vitro, the cell secretions revert the profile of steroid hormones released from the intact ovary. We also present functional evidence for modulation of the immune function by sympathetic nervous system and neurotransmitters other than NE.

Efecto de fracciones pépticas derivadas de la caseína en la absorción de D-xilosa y motilidad intestinal en el perro: estudio preliminar / Effect of casein derived peptides on D-xylose absorption and small intestinal motility

Background: The presence of food in the intestinal lumen increases absorption from an isolated intestinal loop, the mechanisms involved are unknown. Casein, and its respective hydrolysate, increased D-xylose absorption in both normal volunteers and experimental animals; this effect was associated with prolonged small intestinal transit time and a decrease of motor activity. Aims: To separate from casein hydrolysate, groups of peptides and to investigate their effects on both D-xylose absorption and small intestinal motility. Material and methods: Studies were performed on five dogs with a surgically implanted duodenal cannula. Three groups of peptides were separated by means of a Silica Gel 60 column and were continously infused through the duodenal cannula. After 15 min, 5 g of D-xylose were injected in the duodenum, plasma levels were measured, and the area under the curve was estimated. Motility was recorded by means of infused catheters and external transducers. Results: Plasma levels of D-xylose were significantly increased during the infusion of one group of peptides compared to the others. In addition, the area under the curve: 3366 ñ 885 mg x min-1 observed with this group was significantly greater than the other two groups: 1432 ñ 183 mg x min-1 and 1137 ñ 280 mg x min-1 respectively. No statistically significant differences in motor activity were observed between the different groups of peptides. Conclusions: A group of peptides derived from casein was characterized by increasing D-xylose absorption. The presence of beta casomorphines might be the possible mechanism involved

Neuropeptide control of the cardiovascular system in fish and reptiles

Accumulating evidence shows the involvement of neuropeptides in cardiovascular control in mammals as well as non-mammalian species. Our own immunohistochemical studies indicate a sparse innervation only in cyclostomes, holostean fish and lungfish, a more extensive variation and distribution in elasmobranchs and teleosts, and a rich and varied innervation of the cardiovascular system in crocodiles and lizards. Vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), gastrin releasing peptide (GRP) and tachykinins are present in most vertebrate groups. VIP is vasodilatory in the Atlantic cod (Gadus morhua) as in most mammalian species, but increases gut vascular resistance in the spiny dogfish (Squalus acanthias). NPY potentiates the effect of noradrenaline on skate (Raja rhina) coronary vessels, suggesting an interaction between adrenergic mechanisms and NPY early in evolution, but studies in the spiny dogfish and the crocodile also demonstrate different mechanisms for the action of NPY and adrenaline in some species. Bombesin/GRP increases flow to the gut in the spiny dogfish by an increase in somatic vascular resistance, while visceral resistance remains unchanged. In the caiman (Caiman crocodylus crocodylus) bombesin causes a shunting of blood from the lung to the gut. Substance P and other tachykinins in general increase flow to the gut, and on some occasions also increase somatic blood flow. Flow in the anastomosis of the crocodile (Crocodylus porosus) gut is increased by substance P. The results presented here are a review of several published and unpublished studies.

Estimulación electrica del sistema nervioso autonomo y descarga de polipeptido intestinal vasoactivo (VIP) y sustancia (SP) sobre el esfinter esofagico inferior (EEI) / Eletric stimulation of the antonomic nervous system and vasoactive intestinal peptide and substance P discharge on the lower esophageal sphincter

Fue investigado el efecto de la estimulación eléctrica de los nervios esplácnicos y vagos sobre la presión del esfínter esofágico inferior (PEEI) y la secreción de VIP y SP en el drenaje venoso del mismo esfínter. Se utilizó el esfínter esofágico porcino aislado in vivo. La integridad funcional de los nervios autónomos fue comprobada por el efecto de la estimulación nerviosa sobre la frecuencia cardíca. La estimulación vagal aumentó la PEEI 8 veces y la secreción de VIP 3 veces, lo que fue estadísticamente significativo (p , 0.01), mientras que la secreción de SP no fue afectada. La estimulación esplácnica aumentó significativamente la frecuencia cardíaca pero no tuvo efecto sobre la secreción de VIP ni SP y no modificó la PEEI. La atropina abolió parcialmente el efecto de la estimulación vagal sobre la PEEI, pero la secreción de VIP fue completamente resistente al bloqueo atropínico. La administración de guanetidina no tuvo ningún efecto sobre la PEEI ni sobre la secreción de VIP y SP tanto durante la estimulación esplácnica como durante la estimulación vagal. Dado que la estimulación vagal aumenta la secreción de VIP en el EEI sacamos como conclusión que VIP actúa como neurotransmisor. Sin embargo, el hallazgo de resistencia parcial a la atropina en la medición de la PEEI y resistencia total en la secreción de VIP y SP, sugiere que otros transmisores participan en la actividad vagal sobre la PEEI

Polipeptídeo vasoativo intestinal (VIP) no útero de mamíferos: distribuiçäo, origem e efeitos / Vasoactive intestinal polypeptide (VIP) in the mamalian uterus: distribution, origin and effects

Procedeu-se a uma revisäo bibliográfica sobre a distribuiçäo, origem e possíveis papéis fisiológicos do neurotransmissor polipeptídeo vasoactivo intestinal (VIP), no útero. O VIP está presente no útero de mamíferos em geral, localizando-se em fibras nervosas, cujo número é maior na cervice uterina em comparaçäo com o restante do órgäo. As fibras nervosas vipérgicas orientam-se ao longo de células musculares lisas e ao redor de glândulas e vasos sanguíneos, e originam-se dos gânglios nervosos paracervicais, situados na junçäo cérvice uterina-vagina. Os efeitos do VIP no útero, encontrados até o momento, säo os seguintes: 1) relaxamento da musculatura lisa uterina; 2) vasodilataçäo; 3) possível participaçäo em processos secretores.

Dose-dependent effects of vasoactive intestinal polypeptide on somatostatin release from hypothalamic fragments in vitro

Vasoactive intestinal polypeptide (VIP) is present in high concentrations in the hypothalamus and appears to be involved in the modulation of growth hormone (GH) secretion. The effects of VIP on huypothalamic somatostatin (SMS) release are, however, controversial. To further elucidate the mechanism of action of this peptide on GH secretion we studied the effects of VIP on SMS secretion from incubated rat hypothalamic fragments in vitro. At 10**6 M, VIP induced a significant increase in basal SMS release (P<0.01), whereas at 10**-10 M it had an inhibitory effect. We suggest that the increase in GH after in vivo administration of VIP may be modulated, at least in part, by a direct effect of this peptide on SMS neurons, while the stimulatory effect of high doses of VIP on SMS release may represent a pharmacological interaction of this peptide with growth hormone releasing hormone, peptide histidine isoleucine, or glucagon receptors