O objetivo deste estudo foi analisar os efeitos da suplementação com ácido ascórbico (AA) sobre os aspectos morfológicos do plexo mioentérico de camundongos mdx jovens. Foram utilizados camundongos mdx e controles C57BL/10 machos divididos em seis grupos (n=5): GC30 (Grupo controle com 30 dias de idade); GC60 (Grupo controle com 60 dias de idade); GCS60 (Grupo controle suplementado com ácido ascórbico, com 60 dias de idade); GD30 (Grupo distrófico com 30 dias de idade); GD60 (Grupo distrófico com 60 dias de idade) e GDS60 (Grupo distrófico suplementado com AA, com 60 dias de idade). Após a eutanásia, os segmentos orais do jejuno (SOJ) foram coletados e submetidos a técnicas histoquimicas de evidenciação neuronal: NADH-diaforase, NADPH-diaforase e AChE. Os resultados demonstraram um aumento significativo do peso corporal para os animais distróficos (grupos GD30 e GD60) quando comparados aos seus respectivos controles (grupos GC30 e GC60). A análise quantitativa demonstrou que os animais do grupo GD60 possui área total do intestino delgado significativamente maior que os animais do grupo GC60; Não houve diferenças significativas entre os grupos GCS60 e GDS60. Em todos os grupos de animais com 60 dias, exceto para a densidade de neurônios nitrérgicos que se apresentou maior no grupo GCS60, todos os demais parâmetros (densidade e área do perfil neuronal) foram semelhantes entre os grupos, tanto controle (GC60 e GCS60) como distrófico (GD60 E GDS60), nas duas metodologias de coloração utilizadas (NADH-d e NADPH-d). A análise qualitativa demonstrou que componentes do plexo mioentérico dos animais distróficos suplementados com AA (GDS60) evidenciados positivos a NADPH-d e AChE apresentaram manutenção dos aspectos normais do plexo mioentérico quando comparados aos animais do grupo GD60. / The aim of this study was assessment of the effects of ascorbic acid (AA) supplementation on morphoquantitative aspects of myenteric plexus of jejunum young mdx mice. Dystrophic mdx and control C57BL/10 animals were used and divided in six groups (n = 5): GC30 (control group with 30 days of age); GC60 (control group with 60 days of age); GCS60 (control group supplemented with ascorbic acid, 60 days of age); GD30 (dystrophic group 30 days of age); GD60 (dystrophic group 60 days of age) and GDS60 (dystrophic group supplemented with AA, 60 days of age). After euthanasia, the oral segments of the jejunum (SOJ) were collected and submitted to the histochemical techniques of neuronal evidencing: NADH-diaphorase, NADPHdiaphorase and AChE. The results showed a significant increase of weight in dystrophic mice (groups GD30, GD60 and GDS60) compared to its controls (groups GC30, GC60 and GCS60). The quantitative analysis showed that the GD60 group had a significantly higher small intestine total area than the GC60; no differences significant between GCS60 and GDS60 groups. All groups of animals with 60 days of age, except for the density of nitrergic neurons showed higher in GCS60 group, in all other parameters (the neuronal density and neuronal profile area) were similar between groups, controls (GC60 and GCS60) and dystrophic (GD60 e GDS60), for techniques of the NADH-d e NADPH-d.Morphological analysis of the components of myenteric plexus of dystrophic animals supplemented with AA (group GDS60) and evidenced by the techniques of NADPH-d and AChE, showed repair of the myenteric plexus aspects compared to animals of group no supplemented (GD60).

Um metabólito do aminoácido leucina, o HMB, vem sendo utilizado por promover aumento da síntese e/ou redução da degradação protéica. O objetivo do presente estudo avaliou os mecanismos moleculares envolvidos no efeito do HMB sobre o metabolismo proteico na musculatura esquelética frente a um modelo de proteólise, bem como suas consequências funcionais. Ratos Wistar (~250 g) foram tratados com HMB (320 mg/Kg de peso corporal), ou salina (controle), por gavagem, durante 28 dias. Após esse período, uma parcela de ambos os grupos sofreu jejum de 24 horas. Após os tratamentos, parte dos animais foi submetida a ensaios funcionais in vivo. A outra parcela foi sacrificada, os músculos gastrocnêmio (GASTRO) removidos e pesados; sóleo (SOL) e extensor digital longo (EDL), bem como parte do fígado, retirados para avaliação da expressão gênica (real-time PCR) e protéica (Western Blotting) de diversas proteínas envolvidas na síntese e degradação protéica na musculatura esquelética (IGF-I/Akt/mTOR/4E-BP1 e Ub-ligases). Não detectamos alterações na expressão dos atrogenes em ambos os músculos (SOL/EDL) com o tratamento; no entanto observamos um indicativo de atenuação dos animais jejuados com o tratamento no jejum no EDL. Com relação à fosforilação da Akt não houve alteração da mesma com o jejum e nem com o tratamento com HMB no músculo SOL. Já no EDL, encontramos elevação da pAkt no grupo jejuado tratado comparado ao jejuado controle. Contudo, surpreendentemente não detectamos alteração nas demais vias de síntese. Os dados funcionais revelaram apenas uma melhora no tempo de sustentação de isometria e na taxa de resistência à fadiga no EDL dos animais jejuados tratados, sem qualquer alteração na AST. Esta, no entanto, apresentou-se reduzida no SOL. Os resultados obtidos sugerem que o tratamento crônico com HMB não resultou em alterações nas vias de síntese e degradação protéica nos animais submetidos ao jejum. Contudo, eles apontam respostas músculo-específicas direcionadas ao EDL, com aumento da atividade da Akt e uma melhora funcional, sugerindo que o HMB atue protegendo esse músculo do efeito deletério do jejum, sem adicional ganho de massa muscular. / The HMB, a leucine metabolite, has been used for provide muscle mass gain by increasing protein synthesis and / or diminishing its degradations. The aims of this study is to explore the molecular mechanisms involved of the HMB effects over the protein metabolic on skeletal muscle compared to a proteolysis model, as well as their further functional consequences on muscle. Wistar rats (250 g) were treated with HMB (320 mg/kg body weight/mL of saline-0, 9%), or only saline (control) daily by gavage for 28 days along. After it, a group of animals were subjected to 24-hour fast. After the specified treatments, another portion of these animals were submitted to performances test in vivo. Another portion of animals were sacrificed, and their gastrocnemius (GASTRO) removed and weighed; furthermore, the soleus (SOL), extensor digitorum longus (EDL) and a piece of the liver were removed for evaluation of several genes expression (real-time PCR) and their proteins expression (Western Blotting). Those proteins were involved on protein synthesis and degradation of skeletal muscle (IGF-I/Akt/mTOR/4E-BP1 and Ub ligases). After treatment, no changes were detected on the atrogenes expression in both muscles (SOL / EDL); however it can be observed an indicative attenuation of fasted control animals compared HMB treatment fasted on EDL. In relation of Akt phosphorylation, on soleus muscle, it was not altered by fasting, neither by HMB treatment. We found the pAkt elevated on the EDLs muscle of the HMB group fasted compared to the control fasted. However, surprisingly we detected no changes in the other synthesis pathway, as well on IGF-I expressions and its proteins content. Functional data revealed an improvement on sustained time of the isometric force and the fatigue resistance rate on EDL of animals fasted and HMB treated, without any change on cross-sectional area (CSA). On the other hand, it appeared to be reduced in SOL. Those data suggesting that chronic HMB treatment have no change in the synthesis pathways and protein degradations in animals subjected to fasting. Nevertheless, they indicated responses of muscle-specific, mainly the EDL, in which was observed an increase of Akt activity, followed by a functional improvement, suggesting that this metabolite acts as a muscle protector of the deleterious fasting effects, without any additional muscle mass gain.

<p>The subject of this thesis was to study two intestinal barriers to oral drug bioavailability, drug efflux proteins of the ABC-transporter family, and in particular ABCB1/P-glycoprotein (Pgp), and the drug metabolizing enzyme cytochrome P450 (CYP) 3A4. At the onset of this thesis, similarities between CYP3A4 and Pgp in terms of their tissue distribution and gene regulation, along with overlapping substrate specificities, had generated the hypothesis that CYP3A4 and Pgp may have a complementary function and thus form a coordinated intestinal barrier to drug absorption and gut wall metabolism.</p><p>In the first part of this thesis, a cell culture model of the intestinal epithelium that expressed both functional Pgp and CYP3A4 was developed. This model was then used to investigate the steroselective drug efflux and metabolism of R/S-verapamil. In summary, the results indicated that the two barriers in the cell culture model were in agreement with those in the human intestine.</p><p>Both ABC-transporters and CYPs are regulated by drugs that interact with nuclear receptors. However, while the regulation of CYPs is quite well understood, less is known about how repeated drug administration regulates the most abundantly expressed ABC-transporters. Therefore, in the second part of this thesis, the effects of repeated drug administration on the gene regulation of four ABC-transporters and CYP3A4 were studied in intestinal epithelial cell lines in vitro and in the perfused human jejunum in vivo. The in vitro studies revealed that the ABC-transporters are induced by drugs that interact with slightly different sets of nuclear receptors. The in vivo study showed that repeated oral administration of St John’s wort decreased the bioavailability of verapamil, predominantly by induction of intestinal CYP3A4. This part of the thesis provides new information about the regulation of ABC-transporters, shows that the intestinal metabolism is the most significant barrier to oral bioavailability of verapamil and provides evidence for a clinically significant interaction between verapamil and St John’s wort in vivo.</p>

The subject of this thesis was to study two intestinal barriers to oral drug bioavailability, drug efflux proteins of the ABC-transporter family, and in particular ABCB1/P-glycoprotein (Pgp), and the drug metabolizing enzyme cytochrome P450 (CYP) 3A4. At the onset of this thesis, similarities between CYP3A4 and Pgp in terms of their tissue distribution and gene regulation, along with overlapping substrate specificities, had generated the hypothesis that CYP3A4 and Pgp may have a complementary function and thus form a coordinated intestinal barrier to drug absorption and gut wall metabolism. In the first part of this thesis, a cell culture model of the intestinal epithelium that expressed both functional Pgp and CYP3A4 was developed. This model was then used to investigate the steroselective drug efflux and metabolism of R/S-verapamil. In summary, the results indicated that the two barriers in the cell culture model were in agreement with those in the human intestine. Both ABC-transporters and CYPs are regulated by drugs that interact with nuclear receptors. However, while the regulation of CYPs is quite well understood, less is known about how repeated drug administration regulates the most abundantly expressed ABC-transporters. Therefore, in the second part of this thesis, the effects of repeated drug administration on the gene regulation of four ABC-transporters and CYP3A4 were studied in intestinal epithelial cell lines in vitro and in the perfused human jejunum in vivo. The in vitro studies revealed that the ABC-transporters are induced by drugs that interact with slightly different sets of nuclear receptors. The in vivo study showed that repeated oral administration of St John’s wort decreased the bioavailability of verapamil, predominantly by induction of intestinal CYP3A4. This part of the thesis provides new information about the regulation of ABC-transporters, shows that the intestinal metabolism is the most significant barrier to oral bioavailability of verapamil and provides evidence for a clinically significant interaction between verapamil and St John’s wort in vivo.

Resumo: Foi realizado um experimento com frangos de corte machos e fêmeas, com duração de 43 dias, no Aviário Experimental do Departamento de Zootecnia da Faculdade de Ciências Agrárias e Veterinárias, UNESP, Campus de Jaboticabal, SP. O objetivo foi o de avaliar a eficácia de três programas de alimentação contendo virginiamicina, sobre o desempenho, rendimento de carcaça e morfometria intestinal de frangos de corte machos e fêmeas, criados sobre cama reutilizada. Foram utilizados 2.160 pintos de um dia de idade da linhagem Cobb, distribuídos em 72 boxes com 30 aves cada. O delineamento experimental adotado foi em blocos com esquema fatorial 3x2 (três programas alimentares e dois sexos), com doze repetições de 30 aves cada. As dietas experimentais consistiram em: T1 (dieta inicial, crescimento e final, isentas de virginiamicina), T2 (adição de virginiamicina nas dietas inicial, crescimento e final) e T3 (adição de virginiamicina nas dietas inicial e crescimento). Aos 21, 35 e 42 dias de idade foram avaliados os dados de desempenho (peso médio, ganho de peso, consumo de ração, conversão alimentar e viabilidade criatória) e aos 42 dias de idade as características de carcaça (rendimento de carcaça, peito, peito desossado, coxa + sobrecoxa e asas). Aos 43 dias de idade, amostras de duodeno e jejuno foram retiradas para análise de morfometria de altura e largura das vilosidades, profundidade de cripta e relação a altura de vilosidade/profundidade de cripta, no Laboratório de Histologia e Embriologia do Departamento de Morfologia e Fisiologia Animal da FCAV, UNESP. Os tratamentos T2 e T3 proporcionaram melhores resultados para peso, ganho de peso e conversão alimentar, no entanto, não interferiram no consumo de ração, viabilidade criatória e no rendimento de carcaça e cortes quando comparados com o tratamento T1. A utilização de virginiamicina proporcionou melhor ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: An experiment was conducted with broiler males and females, with duration of 43 days in the Experimental Aviary of the Animal Science Department at Agriculture and Veterinary Sciences Faculty, UNESP, Jaboticabal, SP. The objective was to evaluate the efficacy of three feed programs containing virginiamycin on performance, carcass and intestinal morphology of broiler males and females reared on reused litter. We used 2,160 chicks a day old, Cobb, distributed in 72 boxes with 30 birds each. The experiment was arranged in blocks with a 3x2 factorial arrangement (three food programs and two sexes), with twelve replicates of 30 birds each. The experimental diets consisted of T1 (starter, growth and final diet free virginiamycin), T2 (addition of virginiamycin in diets starting, growing and finishing) and T3 (addition of virginiamycin in diets and initial growth). At 21, 35 and 42 days of age were evaluated performance data (average weight, weight gain, feed intake, feed conversion and livability) and at 42 days old carcass characteristics (carcass yield, breast, boneless breast, thigh + drumstick and wings). At 43 days of age, samples of duodenum and jejunum were removed for morphometric analysis of villus height and width, crypt depth and compared villus height/crypt depth in the Histology and Embryology Laboratory, of Morphology and Physiology Departament, from FCAV, UNESP. The treatments T2 and T3 provided better results for weight, weight gain and feed conversion, however, did not affect feed intake, livability and carcass yield and cuts when compared with T1. The use of virginiamycin provided better development of the villi and crypts, when compared with treatment without antibiotic in the study / Orientador: Silvana Martinez Baraldi Artoni / Coorientador: Otto Mack Junqueira / Banca:Antonio Carlos de Laurentiz / Banca: Maria Rita Pacheco / Mestre

Um metabólito do aminoácido leucina, o HMB, vem sendo utilizado por promover aumento da síntese e/ou redução da degradação protéica. O objetivo do presente estudo avaliou os mecanismos moleculares envolvidos no efeito do HMB sobre o metabolismo proteico na musculatura esquelética frente a um modelo de proteólise, bem como suas consequências funcionais. Ratos Wistar (~250 g) foram tratados com HMB (320 mg/Kg de peso corporal), ou salina (controle), por gavagem, durante 28 dias. Após esse período, uma parcela de ambos os grupos sofreu jejum de 24 horas. Após os tratamentos, parte dos animais foi submetida a ensaios funcionais in vivo. A outra parcela foi sacrificada, os músculos gastrocnêmio (GASTRO) removidos e pesados; sóleo (SOL) e extensor digital longo (EDL), bem como parte do fígado, retirados para avaliação da expressão gênica (real-time PCR) e protéica (Western Blotting) de diversas proteínas envolvidas na síntese e degradação protéica na musculatura esquelética (IGF-I/Akt/mTOR/4E-BP1 e Ub-ligases). Não detectamos alterações na expressão dos atrogenes em ambos os músculos (SOL/EDL) com o tratamento; no entanto observamos um indicativo de atenuação dos animais jejuados com o tratamento no jejum no EDL. Com relação à fosforilação da Akt não houve alteração da mesma com o jejum e nem com o tratamento com HMB no músculo SOL. Já no EDL, encontramos elevação da pAkt no grupo jejuado tratado comparado ao jejuado controle. Contudo, surpreendentemente não detectamos alteração nas demais vias de síntese. Os dados funcionais revelaram apenas uma melhora no tempo de sustentação de isometria e na taxa de resistência à fadiga no EDL dos animais jejuados tratados, sem qualquer alteração na AST. Esta, no entanto, apresentou-se reduzida no SOL. Os resultados obtidos sugerem que o tratamento crônico com HMB não resultou em alterações nas vias de síntese e degradação protéica nos animais submetidos ao jejum. Contudo, eles apontam respostas músculo-específicas direcionadas ao EDL, com aumento da atividade da Akt e uma melhora funcional, sugerindo que o HMB atue protegendo esse músculo do efeito deletério do jejum, sem adicional ganho de massa muscular. / The HMB, a leucine metabolite, has been used for provide muscle mass gain by increasing protein synthesis and / or diminishing its degradations. The aims of this study is to explore the molecular mechanisms involved of the HMB effects over the protein metabolic on skeletal muscle compared to a proteolysis model, as well as their further functional consequences on muscle. Wistar rats (250 g) were treated with HMB (320 mg/kg body weight/mL of saline-0, 9%), or only saline (control) daily by gavage for 28 days along. After it, a group of animals were subjected to 24-hour fast. After the specified treatments, another portion of these animals were submitted to performances test in vivo. Another portion of animals were sacrificed, and their gastrocnemius (GASTRO) removed and weighed; furthermore, the soleus (SOL), extensor digitorum longus (EDL) and a piece of the liver were removed for evaluation of several genes expression (real-time PCR) and their proteins expression (Western Blotting). Those proteins were involved on protein synthesis and degradation of skeletal muscle (IGF-I/Akt/mTOR/4E-BP1 and Ub ligases). After treatment, no changes were detected on the atrogenes expression in both muscles (SOL / EDL); however it can be observed an indicative attenuation of fasted control animals compared HMB treatment fasted on EDL. In relation of Akt phosphorylation, on soleus muscle, it was not altered by fasting, neither by HMB treatment. We found the pAkt elevated on the EDLs muscle of the HMB group fasted compared to the control fasted. However, surprisingly we detected no changes in the other synthesis pathway, as well on IGF-I expressions and its proteins content. Functional data revealed an improvement on sustained time of the isometric force and the fatigue resistance rate on EDL of animals fasted and HMB treated, without any change on cross-sectional area (CSA). On the other hand, it appeared to be reduced in SOL. Those data suggesting that chronic HMB treatment have no change in the synthesis pathways and protein degradations in animals subjected to fasting. Nevertheless, they indicated responses of muscle-specific, mainly the EDL, in which was observed an increase of Akt activity, followed by a functional improvement, suggesting that this metabolite acts as a muscle protector of the deleterious fasting effects, without any additional muscle mass gain.

O objetivo deste estudo foi analisar os efeitos da suplementação com ácido ascórbico (AA) sobre os aspectos morfológicos do plexo mioentérico de camundongos mdx jovens. Foram utilizados camundongos mdx e controles C57BL/10 machos divididos em seis grupos (n=5): GC30 (Grupo controle com 30 dias de idade); GC60 (Grupo controle com 60 dias de idade); GCS60 (Grupo controle suplementado com ácido ascórbico, com 60 dias de idade); GD30 (Grupo distrófico com 30 dias de idade); GD60 (Grupo distrófico com 60 dias de idade) e GDS60 (Grupo distrófico suplementado com AA, com 60 dias de idade). Após a eutanásia, os segmentos orais do jejuno (SOJ) foram coletados e submetidos a técnicas histoquimicas de evidenciação neuronal: NADH-diaforase, NADPH-diaforase e AChE. Os resultados demonstraram um aumento significativo do peso corporal para os animais distróficos (grupos GD30 e GD60) quando comparados aos seus respectivos controles (grupos GC30 e GC60). A análise quantitativa demonstrou que os animais do grupo GD60 possui área total do intestino delgado significativamente maior que os animais do grupo GC60; Não houve diferenças significativas entre os grupos GCS60 e GDS60. Em todos os grupos de animais com 60 dias, exceto para a densidade de neurônios nitrérgicos que se apresentou maior no grupo GCS60, todos os demais parâmetros (densidade e área do perfil neuronal) foram semelhantes entre os grupos, tanto controle (GC60 e GCS60) como distrófico (GD60 E GDS60), nas duas metodologias de coloração utilizadas (NADH-d e NADPH-d). A análise qualitativa demonstrou que componentes do plexo mioentérico dos animais distróficos suplementados com AA (GDS60) evidenciados positivos a NADPH-d e AChE apresentaram manutenção dos aspectos normais do plexo mioentérico quando comparados aos animais do grupo GD60. / The aim of this study was assessment of the effects of ascorbic acid (AA) supplementation on morphoquantitative aspects of myenteric plexus of jejunum young mdx mice. Dystrophic mdx and control C57BL/10 animals were used and divided in six groups (n = 5): GC30 (control group with 30 days of age); GC60 (control group with 60 days of age); GCS60 (control group supplemented with ascorbic acid, 60 days of age); GD30 (dystrophic group 30 days of age); GD60 (dystrophic group 60 days of age) and GDS60 (dystrophic group supplemented with AA, 60 days of age). After euthanasia, the oral segments of the jejunum (SOJ) were collected and submitted to the histochemical techniques of neuronal evidencing: NADH-diaphorase, NADPHdiaphorase and AChE. The results showed a significant increase of weight in dystrophic mice (groups GD30, GD60 and GDS60) compared to its controls (groups GC30, GC60 and GCS60). The quantitative analysis showed that the GD60 group had a significantly higher small intestine total area than the GC60; no differences significant between GCS60 and GDS60 groups. All groups of animals with 60 days of age, except for the density of nitrergic neurons showed higher in GCS60 group, in all other parameters (the neuronal density and neuronal profile area) were similar between groups, controls (GC60 and GCS60) and dystrophic (GD60 e GDS60), for techniques of the NADH-d e NADPH-d.Morphological analysis of the components of myenteric plexus of dystrophic animals supplemented with AA (group GDS60) and evidenced by the techniques of NADPH-d and AChE, showed repair of the myenteric plexus aspects compared to animals of group no supplemented (GD60).

The intestinal epithelium is able to adapt to varying blood flow and, thus, oxygen availability. Still, the adaptation fails under pathologic situations. A better understanding of the mechanisms underlying the epithelial adaptation to hypoxia could help to improve the therapeutic approach. We hypothesized that the short-term adaptation to hypoxia is mediated via AMP-activated protein kinase (AMPK) and that it is coupled to the long-term adaptation by a common regulation mechanism, the HIF-hydroxylase enzymes. Further, we hypothesized the transepithelial transport of glucose to be part of this short-term adaptation. We conducted Ussing chamber studies using isolated lagomorph jejunum epithelium and cell culture experiments with CaCo-2 cells. The epithelia and cells were incubated under 100% and 21% O2, respectively, with the panhydroxylase inhibitor dimethyloxalylglycine (DMOG) or under 1% O2. We showed an activation of AMPK under hypoxia and after incubation with DMOG by Western blot. This could be related to functional effects like an impairment of Na+-coupled glucose transport. Inhibitor studies revealed a recruitment of glucose transporter 1 under hypoxia, but not after incubation with DMOG. Summing up, we showed an influence of hydroxylase enzymes on AMPK activity and similarities between hypoxia and the effects of hydroxylase inhibition on functional changes.

The HIF prolyl 4-hydroxylases (HIF-P4H) control hypoxia-inducible factor (HIF), a powerful mechanism regulating cellular adaptation to decreased oxygenation. The gastrointestinal epithelium subsists in “physiological hypoxia” and should therefore have an especially well-designed control over this adaptation. Thus, we assessed the absolute mRNA expression levels of the HIF pathway components, Hif1a, HIF2a, Hif-p4h-1, 2 and 3 and factor inhibiting HIF (Fih1) in murine jejunum, caecum and colon epithelium using droplet digital PCR.We found a higher expression of all these genes towards the distal end of the gastrointestinal tract. We detected mRNA for Hif-p4h-1, 2 and 3 in all parts of the gastrointestinal tract. Hif-p4h-2 had significantly higher expression levels compared to Hif-p4h-1 and 3 in colon and caecum epithelium. To test the roles each HIF-P4H isoform plays in the gut epithelium, we measured the gene expression of classical HIF target genes in Hif-p4h-1/, Hif-p4h-2 hypomorph and Hif-p4h-3/ mice. Only Hif-p4h-2 hypomorphism led to an upregulation of HIF target genes, confirming a predominant role of HIF-P4H-2. However, the abundance of Hif-p4h-1 and 3 expression in the gastrointestinal epithelium implies that these isoforms may have specific functions as well. Thus, the development of selective inhibitors might be useful for diverging therapeutic needs.

A reconstrução microcirúrgica de faringe e esôfago com jejuno é uma das opções para a reparação de defeitos resultantes de faringolaringectomias. Suas principais vantagens são: o diâmetro da alça jejunal é compatível com o diâmetro das bocas faríngea e esofágica, apresenta menos estenose do que reconstruções cutâneas e há menos contaminação do que quando se emprega o cólon. Entretanto, o pedículo vascular é, por vezes, curto; além disso, as paredes flácidas do intestino delgado e sua secreção mucosa dificultam a adaptação de prótese fonatórias. Finalmente, é necessária uma laparotomia para a obtenção do segmento jejunal, o que aumenta a potencial morbidade operatória. O objetivo deste trabalho foi avaliar de forma retrospectiva os aspectos técnicos, mobi-mortalidade e resultados funcionais de uma série de doentes submetidos a este método reconstrutivo, numa única instituição. No período de 1989 a 2000, 35 pacientes do sexo masculino, com média de idade de 55 anos, foram submetidos à reconstrução faringoesofágica com retalho microcirúrgico de jejuno, no Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Trinta e quatro doentes eram portadores de tumores malignos do trato aerodigestivo alto, e um sofreu um ferimento cervical por arma de fogo. Onze casos foram previamente submetidos à radioterapia. A reconstrução foi imediata na maioria dos casos (85,7%). Através de laparotomia mediana supra-umbilical, escolheu-se segmento de alça jejunal de tamanho compatível, situado de 30 a 50 cm do ângulo do Treitz e nutrido por ramos longos dos vasos mesentéricos superiores, atentando-se para preservar a continuidade da arcada vascular primária em todo o segmento a ser transplantado. Este foi transposto para o seu leito definitivo sempre em posição isoperistáltica. Obteve-se um restabelecimento do trânsito digestivo alto em 84,0% dos casos. Houve perda do retalho em 14%, e a taxa de mortalidade foi de 2,9%, ocasionada por abdome agudo obstrutivo. O resultado funcional foi avaliado através de escala de pontuação de Schechter, incluindo parâmetros como deglutição, voz e peso corpóreo. Em 45% dos casos, observou-se uma pontuação entre 5 e 6, evidenciando uma boa qualidade de reabilitação. Em virtude da gravidade dos doentes e da magnitude dos atos operatórios, concluiu-se que a reconstrução faringoesofágica com retalho microcirúrgico jejunal foi um método exeqüível em nosso meio, oferecendo uma boa qualidade de reabilitação funcional, com morbi-mortalidade aceitável / Microsurgical reconstruction of the esophagus and pharynx with a jejunal segment is one of the current options available for repairing defects caused by pharyngolaryngectomies. Main advantages of this technique are: compatible diameters of the jejunal segment with the pharyngeal and esophageal openings, lower incidence of stenosis when compared to cutaneous reconstructions, and less contamination in relation to techniques using colonic fragments. Nevertheless, the vascular pedicle is sometimes too short and the flaccid walls of the jejunum associated with its mucous secretion render adaptation to phonatory prosthesis more difficult. Finally, operative morbidity may be increased due to the need for laparotomy in order to obtain the jejunal segment. The aim of this work was to evaluate, in a retrospective fashion, the technical aspects, morbi-mortality and functional results of a series of patients submitted to this reconstructive method at a single institution. During the period of 1989 to 2000 a total of 35 male patients with an average age of 55 years received a microsurgical flap of the jejunum for pharyngoesophageal reconstruction, at the Hospital das Clínicas of São Paulo University Medical School. Thirty four patients had malignant tumors of the upper aerodigestive tract and one had a injury. Eleven cases had been previously submitted to radiotherapy. The majority of patients (85.7%) underwent reconstruction immediately following ablative surgery. By means of median supraumbilical laparotomy an intestinal segment located 30 to 50 cm away from the angle of Treitz was chosen taking into note that it had to be nourished by long branches of the superior mesenteric vessels and to also maintain its continuity to the primary vascular arcade throughout the segment to be transplanted. The segment was transposed to its definitive vascular bed always respecting an isoperistaltic position. Functional effective restoration of the higher digestive transit was possible in 84.0% of cases. Graft loss occurred in 14%, and the mortality rate was of 2.9%, caused by obstructive acute abdomen. Functional results were evaluated according to the Schechter scoring scale, where parameters such as swallowing, voice and weight are taken into account. In 45% of the cases the scores were between 5 and 6, representing good repairing quality. Considering the degree of severity of these patients and the magnitude of the surgical procedures, we concluded that pharyngoesophageal reconstruction utilizing microsurgical jejunal flaps is a feasible method with good functional rehabilitation results and acceptable morbidity and mortality rates for our patient population