Maternal protein restriction affects gene expression and enzyme activity of intestinal disaccharidases in adult rat offspring

This study investigated the consequences of intrauterine protein restriction on the gastrointestinal tract and particularly on the gene expression and activity of intestinal disaccharidases in the adult offspring. Wistar rat dams were fed isocaloric diets containing 6% protein (restricted, n = 8) or 17% protein (control, n = 8) throughout gestation. Male offspring (n = 5-8 in each group) were evaluated at 3 or 16 weeks of age. Maternal protein restriction during pregnancy produced offspring with growth restriction from birth (5.7 ± 0.1 vs 6.3 ± 0.1 g; mean ± SE) to weaning (42.4 ± 1.3 vs 49.1 ± 1.6 g), although at 16 weeks of age their body weight was similar to control (421.7 ± 8.9 and 428.5 ± 8.5 g). Maternal protein restriction also increased lactase activity in the proximal (0.23 ± 0.02 vs 0.15 ± 0.02), medial (0.30 ± 0.06 vs 0.14 ± 0.01) and distal (0.43 ± 0.07 vs 0.07 ± 0.02 U·g-1·min-1) small intestine, and mRNA lactase abundance in the proximal intestine (7.96 ± 1.11 vs 2.38 ± 0.47 relative units) of 3-week-old offspring rats. In addition, maternal protein restriction increased sucrase activity (1.20 ± 0.02 vs 0.91 ± 0.02 U·g-1·min-1) and sucrase mRNA abundance (4.48 ± 0.51 vs 1.95 ± 0.17 relative units) in the duodenum of 16-week-old rats. In conclusion, the present study shows for the first time that intrauterine protein restriction affects gene expression of intestinal enzymes in offspring.

Effect of glutamine on the mRNA level of key enzymes of malate-aspartate shuttle in the rat intestine subjected to ischemia reperfusion / Efeito da glutamina sobre o nível de RNA Mensageiro das enzimas-chave do ciclo malato-aspartato no intestino de ratos submetidos à isquemia e reperfusão

PURPOSE: To determine the effects of oral L-glutamine (L-Gln) and the dipeptide l-alanyl-glutamine (L-Ala-Gln) upon the activity of the malate-aspartate shuttle in the rat distal small intestine following ischemia and reperfusion. METHODS: Seventy-two Wistar rats (350-400g), were randomized in 2 groups (n = 36): group S (Sham) and Group T (Treatment) and divided into 12 subgroups (n = 6): A-A6, and B1-B6. The subgroups A1-A3 were subjected to sham procedures at 30 and 60 minutes. Thirty minutes before the study, rats were treated with calcium caseinate, 0.5g/Kg (subgroups A1, A4, B1, B4), L-Gln, 0.5g / kg (subgroups A2, A5, B2 and B5) or L-Ala-Gln, 0.75g/Kg (subgroups A3, A6, B3, B6), administered by gavage. Ischemia was achieved by clamping the mesenteric vessels, delimiting a segment of bowel 5 cm long and 5 cm apart from the ileocecal valve. Samples were collected 30 and 60 minutes after start of the study for real-time PCR assay of malate dehydrogenases (MDH1-2) and aspartate-aminotransferases (GOT1-2) enzymes. RESULTS: Tissue MDH and GOT mRNA expression in intestinal samples from rats preconditioned with either L-Gln or L-Ala-Gln showed no significant differences both during ischemia and early reperfusion. CONCLUSION: Activation of the malate-aspartate shuttle system appears not to be the mechanism of glutamine-mediated elevation of glucose oxidation in rat intestine during ischemia/reperfusion injury.

OBJETIVO: Determinar os efeitos da administração oral de L-glutamina (L-Gln) e do dipeptídeo L-alanil-glutamina (L-Ala-Gln) sobre a atividade do ciclo malato-aspartato no intestino delgado distal de ratos após isquemia/reperfusão. MÉTODOS: Setenta e dois ratos Wistar (350-400g) foram randomizados em 2 grupos (n = 36): T grupo S (Sham) e grupo (Tratamento) e distribuídos em 12 subgrupos (n = 6): A-A6, e B1-B6. Os subgrupos A1-A3 foram submetidos a procedimentos "sham" aos 30 e 60 minutos. Trinta minutos antes do estudo, os ratos foram tratados com caseinato de cálcio, 0,5 g/kg (subgrupos A1, A4, B1 e B4), L-Gln, 0,5 g/kg (subgrupos A2, A5, B2 e B5) ou L-Ala -Gln, 0,75g/kg (subgrupos A3, A6, B3, B6), administrado por gavagem. A isquemia foi obtida por pinçamento dos vasos mesentéricos, delimitando um segmento do intestino cinco centímetros de comprimento e 5 cm da válvula ileocecal. Amostras foram coletadas aos 30-60 minutos para ensaio de PCR em tempo real das enzimas malato desidrogenases (MDH1-2), aspartato-aminotransferase (GOT1-2). RESULTADOS: A expressão de MDH e GOT mRNA nas amostras provenientes do intestino delgado de ratos pré-condicionados com L-Gln ou L-Ala-Gln não apresentou diferenças significativas, tanto durante a isquemia como na fase inicial de reperfusão. CONCLUSÃO: Ativação do ciclo malato-aspartato não parece ser o mecanismo de elevação glutamina-mediada da oxidação da glicose no intestino de ratos durante a isquemia / reperfusão.

Atividade da catalase no pulmão, rim e intestino delgado não isquemiado de ratos após reperfusão intestinal / Catalase activity in lung, kidney and small bowel non-ischemic in rats after intestinal reperfusion

OBJETIVO: Avaliar a atividade catalase, após lesão por isquemia e reperfusão intestinal e estudar as alterações deste antioxidante em órgãos situados à distância do insulto inicial. MÉTODOS: Utilizaram-se 18 ratos do tipo Wistar, aleatoriamente distribuídos em três grupos. 1-Controle, 2-Simulação e 3-Isquemia/Reperfusão. Neste último, realizou-se isquemia no íleo, por 60 minutos, seguida de reperfusão por 30 minutos. No grupo 2 efetuou-se apenas uma laparotomia. Foram retirados, de todos os animais, segmentos do intestino com e sem reperfusão, além do pulmão e rim direitos para exame com microscopia óptica. A atividade da catalase foi aferida em espectrofotômetro ajustado para 240 nm. Utilizaram-se os testes estatísticos Mann e Whitney e Kruskal Wallis. RESULTADOS: Observou-se aumento significante (p < 0.05), da atividade da catalase nas porções do intestino isquemiado e não isquemiado, além do pulmão. Houve redução da atividade enzimática no rim. No grupo com reperfusão observaram-se alteração nas vilosidades, infiltrado inflamatório em todas as vísceras, além de áreas de atelectasia pulmonar. CONCLUSÃO: O estresse oxidativo intestinal, em ratos, causa alterações bioquímicas à distância com mobilização dos mecanismos de defesa antioxidante pulmonar, em segmento intestinal não isquemiado e no rim, com esgotamento precoce das reservas deste último, no entanto, sem lesão celular relevante, destas vísceras.

OBJECTIVE: This study aimed to assess the catalase activity after ischemia and reperfusion and to study the changes of this antioxidant in organs located far from the initial insult. METHODS: Eighteen Wistar rats were randomly divided into three groups. 1-Control, 2-Simulation and 3-Ischemia and Reperrfusion. In the latter it was done an ischemia of the ileum for 60 minutes followed by reperfusion for 30 minutes. In group 2 only laparotomy was performed. From all animals it was taken segments of the reperfused and non reperfused intestine, as well of the right kidney and lung to be evaluated under light microscopy. Catalase activity was measured in spectrophotometer with a wavelength set to 240 nm. It was used Mann Whitney and Kruskal Wallis statistical tests. RESULTS: There was a significant increase (p <0.05) in the catalase activity not only at small bowel ischemic and non-ischemic segments but also at lungs. However the enzymatic activity decreases in the kidney. In all organs studied at reperfusion group it was found a slight villi derangement, mild congestion and infiltration with inflammatory cells, and areas of pulmonary atelectasis. CONCLUSION: The intestinal oxidative stress in rats causes biochemical changes at distance, with mobilization of antioxidant defense mechanisms in lung, non-ischemic intestinal segment and kidney, with early decrease in this last organ, however, with no relevant cellular damage.

Coordinated secretion of alkaline phosphatase into serum and intestine in fat-fed rats.

BACKGROUND: Fat feeding increases the activity of intestinal alkaline phosphatase in the serum. The mechanism underlying this increase is unknown. Surfactant-like particles (SLP) secreted by enterocytes have been implicated in this phenomenon. OBJECTIVE: To study the effect of feeding fish oil and protein synthesis inhibitors on alkaline phosphatase activity in serum and in different intestinal fractions. METHODS: Male albino rats were fed 2 mL of fish oil and were injected cycloheximide or actinomycin D. Alkaline phosphatase activity was determined in the serum and intestinal fractions (SLP, mucosa, muscularis). RESULT: Feeding fish oil significantly elevated alkaline phosphatase activity in serum (p< 0.001) and intestinal mucosa (p< 0.01). Administration of cycloheximide or actinomycin D significantly reduced alkaline phosphatase activity in serum (p< 0.01) and in intestinal mucosa (p< 0.05). BCIP staining of brush border alkaline phosphatase activity in acrylamide gels yielded similar results. CONCLUSIONS: These findings suggest a co-ordination between alkaline phosphatase synthesis and its assembly into lipoprotein vesicles, such as SLP, secreted by enterocytes in response to fat feeding.

Relation of the disaccharidases in the small intestine of the rat to the degree of experimentally induced iron-deficiency anemia

Hypolactasia associated with severe iron-deficiency anemia has been reported in several studies. The objective of the present study was to determine whether hypolactasia is associated with the degree and duration of iron-deficiency anemia. Newly weaned male Wistar rats were divided into a control group receiving a diet supplemented with iron (C) and an experimental group (E) receiving a diet not supplemented with iron (iron-deficiency diet). The animals were studied on the 3rd, 5th, 7th, 14th, 21st, 28th and 35th days of the experiment, when overall and iron nutritional status and disaccharidase activity in the small intestine were determined by the Dahlqvist method. A reduction in weight occurred in the anemic animals starting on the 5th day of the study. Anemia was present in the experimental animals, with a progressive worsening up to the 14th day (hemoglobin: C = 13.27 and E = 5.37) and stabilizing thereafter. Saccharase and maltase activities did not differ significantly between groups, whereas lactase showed a significant reduction in total (TA) and specific activity (SA) in the anemic animals starting on the 21st day of the study. Median lactase TA for the C and E groups was 2.27 and 1.25 U on the 21st day, 2.87 and 1.88 U on the 28th day, and 4.20 and 1.59 U on the 35th day, respectively. Median lactase SA was 0.31 and 0.20 U/g wet weight on the 21st day, 0.39 and 0.24 U/g wet weight on the 28th day, and 0.42 and 0.23 U/g wet weight on the 35th day, respectively. These findings suggest a relationship between the enzymatic alterations observed and both the degree and duration of the anemic process. Analysis of other studies on intestinal disaccharidases in anemia suggests that the mechanism of these changes may be functional, i.e., that the enterocytes may suffer a reduction in their ability to synthesize these enzymes.

Ontogeny of the small intestine

During development the gastrointestinal tract undergoes marked changes in many physiological and anatomic properties. The remarkable degree of coordination between the development of the gastrointestinal function suggests that the processes may be signalled by some factors, such as weaning, nutrient intake, growth and hormones. The interactions between nutrition and intestinal development begin when fetuses start swallowing amniotic fluid and extend past weaning. Hormonal control plays a major role in the ontogeny of the small intestine. There are late effects of early nutrition, and the normal progress of ontogeny may be important to ensure that the intestine is capable of adaptation in later life.

Análise das alteraçöes do óxido nítrico em pacientes com megacólon chagásico / Analysis of the alterations of nitric oxide in the patient with megacolon in Chaga's disease

A fisiopatologia da Doença de Chagas ainda näo está completamente esclarecida. O óxido nítrico (NO) tem sido citado como neurotransmissor responsável pelo relaxamento do esfíncter interno do ânus no indivíduo normal. Neuronal nicotinamida adenina dinucleotídeo fosfato (NADPH) diaforase pode ser usado como marcador neuronal do NO. Objetivos: Examinar as alteraçöes nos neurônios produtores de NO do cólon de pacientes submetidos à ressecçäo por megacólon avançado e comparar com o intestino delgado dos mesmos pacientes e com controles. Métodos: Espécimes obtidos da ressecçäo do reto e biópsias extramucosas do intestino delgado de 11 pacientes chagásicos foram comparadas a 10 pacientes controles com câncer de cólon. Os tecidos foram fixados em soluçäo de Zamboni e submetidos à histoquímica para neurônios contendo NADPH diaforase. A reatividade foi avaliada utilizando-se uma escala de 0 a 4 nas diversas camadas da parede intestinal: musculatura lisa longitudinal (ML), plexo mioentérico (PM), musculatura lisa circular (MC), plexo submucoso (PSM), e mucosa (M). Resultados: Os casos controles mostraram os plexos mioentérico e submucoso bem corados e uma rica rede de terminaçöes nervosas nas camadas musculares. Os espécimes provenientes de doentes chagásicos revelaram uma diminuiçäo da reatividade e da coloraçäo em todas as camadas do intestino. De maneira geral, houve uma diminuiçäo estatisticamente significante nos neurônios contendo NADPH diaforase. O intestino delgado clinicamente näo envolvido também demonstrou diminuiçäo da reatividade, porém em menor grau. Conclusöes: A atividade da NADPH diaforase está diminuída em pacientes com megacólon avançado, especialmente no plexo mioentérico e na camada muscular lisa; 2. Houve também uma diminuiçäo da atividade neuronal do NO no jejuno clinicamente näo envolvido pela doença, mas em menor grau

A variant of ornithine aminotransferase from mouse small intestine

The ornithine aminotransferase (OAT) activity of mouse was found to be highest in the small intestine. The mitochondrial OAT from mouse small intestine was purified to homogeneity by the procedures including heart treatment, ammonium sulfate fractionation, octyl-Sepharose chromatography, and Sephadex G-150 gel filtration. Comparing to the amino acid sequence of mouse hepatic OAT, six N-terminal amino acid residues have been deleted in intestinal OAT. However, the subsequent sequence was identical with that of hepatic OAT. The molecular weights of both intestinal and hepatic OAT were estimated as 46 kDa by SDS-gel electrophoresis and as 92 kDa by gel filtration, indicating that both native OATs are dimeric. Biochemical properties of intestinal OAT, such as molecular weight, pH optimum and K(m) values for L-ornithine and alpha-ketoglutarate, were similar to those of hepatic OAT. However, intestinal OAT was more labile than hepatic OAT to tryptic digestion.

Alterations in rat intestinal sucrase and alkaline phosphatase activities in alloxan induced experimental diabetes.

Rat intestines revealed a significant loss of proteins after seven days of alloxan induced diabetes. The data suggested the presence of two forms of alkaline phosphatase (ALP) in normal rat intestines. Along with the loss of proteins from the intestines during diabetes, a form of ALP which appears to be loosely bound to the intestine is also flushed out. Total brush border membrane (BBM) proteins are relatively preserved from such leaching effect of alloxan induced diabetes. Thus, sucrase and another form of ALP which appears to be strongly bound to the BBM are flushed out at a slower rate as compared to the other intestinal proteins and loosely bound soluble ALP. BBM preparations from diabetic rat intestines showed lower ratios for BBM/intestinal homogenate sucrase or ALP activity/mg proteins as compared to the normal control rats. Such ratios, therefore, misdepict the purity as low for the BBM from diabetic rats which is merely because of the decreased contents of proteins in the intestinal homogenate during alloxan-induced acute experimental diabetes.

Effect of lactose induced diarrhea on intestinal glutaminase and muscle glutamine synthetase activities in rats

O objetivo deste estudo foi avaliar o efeito da diarréia induzida por lactose na senzimas chaves do metabolismo de glutamina no músculo esqulético e no intestino delgado, em ratos. Comparados com os controles de peso pareado, os animais com diarréia apresentaram atividade maior de glutamina sintetase do músculo, concomitante com uma reduçäo na concentraçäo de glutamina nesse tecido, e uma queda na concentraçäo de glutamina arterial. Essas alteraçöes säo semelhantes àquelas relatadas por outros investigadores em condiçöes em que ocorre a proteólise muscular tais como, durante a fase pós-operatória e septicemia. Além dos dados que sugerem alteraçöes gerais no metabolismo da glutamina, um achado importante deste estudo foi a verificaçäo de aumento na atividade específica de glutaminase intestinal dependente de fosfato em ratos com diarréia. A alteraçäo da atividade dessa enzima näo tem sido demonstrada em diveresas condiçöes tais como, acidose, alcalose, aumento na ingestäo de gluamina através de água ou dieta, situaçöes que supostamente, poderiam interferir na sua atividade

Some properties of monkey intestinal sucrase.

A detergent solubilised sucrase from monkey small intestine has been purified 388-fold to gel electrophoretic homogeneity with an overall recovery of 36%. The molecular weight of the enzyme was 263 kDa by gel filtration. Electrophoresis in the presence of SDS indicates that the enzyme is a hetero-dimer. Mixed substrate inhibition studies and inhibition by PCMB and Tris suggest the presence of two catalytically active sites in the form of maltase and sucrase with isomaltase activity being common to both sites. Polyclonal antiserum against the purified enzyme showed a single continuous precipitin line with the purified antigen.

Purification of rat intestinal cinnabarinate synthase and its possible role in hyperplasia of the small intestine in diabetic rats.

Streptozotocin diabetic rats fed ad libitum exhibited hyperplasia of the small intestine. As compared to the control animals, the intestine of experimental animals grew in weight, length and total RNA and DNA contents. Intestinal cinnabarinate synthase activity in diabetic rats was however significantly lower. Developmental studies in albino rats indicated that, attainment of the terminal and highest activity of the enzyme tends to correspond with cessation of further increase in RNA and DNA contents of the intestine, thereby suggesting a possible relationship between cinnabarinate synthase and the hyperplastic changes observed. It was also observed that some properties of this enzyme, such as Km and Vmax are modified in diabetic condition. The enzyme was purified to apparent homogeneity and some of its kinetic and other properties were studied.

The activity of gamma-glutamyl transpeptidase in the small intestine of some species of animals at different stages of growth.

The activity of gamma-glutamyl transpeptidase (GTP), the key enzyme of gamma-glutamyl cycle, was studied in the intestine of new born, suckling and adult animals (rats, mice, guinea pigs and rabbits). In all the four species, the activity of GTP was greater in new borns than in adults. The activity was highest in rats and almost negligible in guinea pigs.

Atividade dissacaridásica intestinal da esquistossomose mansônica: estudo evolutivo em camundongos com diferentes cargas de infestaçäo / Intestinal activity of disaccharides in schistosomiasis mansoni: study of the course in mice with different loads of infestation

A esquistossomose mansônica compromete vários órgäos, sendo o intestino e o fígado os mais agredidos. Com a intençäo de verificar o comprometimento do intestino delgado, dependente da intensidade e do tempo de infecçäo pelo Schistosoma mansoni, analisou-se a atividade das dissacaridases - lactase, sacarase e maltase - em 112 camundongos, distribuídos em 3 grupos: grupo I - controle, grupo II - infestado com 30 cercárias, grupo III - infestado com 60 cercárias. Observou-se uma diminuiçäo da atividade lactásica, sacarásica e maltásica do intestino delgado, decorrente da infestaçäo esquistossomótica, do tempo de infestaçäo e da alteraçäo entre ambos. O íleo é o segmento que demonstrou maior sensibilidade a esquistossomose, tendo uma diminuiçäo das suas dissacaridases a partir da fase inicial de infestaçäo. Opostamente, o jejuno só mais tardiamente mostra essas alteraçöes, exceto em relaçäo a lactase. Detectou-se um aumento da atividade dissacaridásica, inclusive para a lactase, em todos os grupos, com a evoluçäo etária dos animais, quantitativamente menor nos infestados. Cargas de 30 e 60 cercárias devem ser consideradas do mesmo porte, pois produziram reduçäo semelhante na atividade dissacaridásica

Estudio comparativo del efecto de acetato de hidrocortisona y la prednisolona sobre la actividad de algunas enzimas intestinales / Comparative study of hydrocortisone acetate and prednisolone effect on some intestinal enzymes activites

Se estudia el efecto que produce el acetato de hidrocortisona y la prednisolona en ratas de 12 días de nacidas que habían sido previamente inyectadas durante 3 días consecutivos con una dosis de 50 mg/kg de peso. Se observó que el efecto del acetato de hidrocortisona fue más intenso que el de la prednisolona al incrementar la actividad de la sacarasa y la leucina aminopeptidasa; y que el efecto de la prednisolona fue más intenso que el del acetato de hidrocortisona al incrementar la actividad de la fosfatasa alcalina y al disminuir la ß galactosidasa ácida y la catepsina D. Además, ninguna de las dos hormonas provocó cambio en la lactato deshidrogenasa. Se concluye que aunque el efecto de ambas hormonas es diferente desde el punto de vista cuantitativo, la prednisolona es capaz de producir los cambios de los niveles enzimáticos de forma similar a los que provoca el acetato de hidrocortisona