Elizabeth Lage Borges

Influence of Obstructive Jaundice on Jejunal Absorption of Glucose, Electrolytes, and Vitamin A in Rats

Jejunal absorption of glucose, electrolytes, andvitamin A was investigated in rats. A Tyrode solutioncontaining glucose, sodium, and potassium inconcentrations two and four times higher than usual was infused through the jejunal loops of jaundicedand control rats during 40 min. The glucose values inthe influx and effluent were not different during theexperiment time. However, the concentrations of sodium and potassium of the effluent decreasedwith concentrations twice normal. The osmotic pressureof the effluent was directly related to the electrolyticconcentration. When the perfusate fluid was four times higher, the differences between shamand jaundiced groups remained unchanged. The osmoticpressure means of the jaundiced group decreased duringthe experimental time. The absorption of vitamin A increased during the 40-min experiment timein the control rats. On the other hand, vitamin Aconcentration in the perfused lumen of the jaundicedgroup did not change over the time. These data indicate that obstructive jaundice has little influenceon glucose and electrolytes absorption, while vitamin Ais impaired by this condition.

Intestinal absorption and histomorphometry of Syrian hamsters (Mesocricetus auratus) experimentally infected with Lawsonia intracellularis

The objective of this study was to evaluate the intestinal absorption and histomorphometry of hamsters experimentally infected with Lawsonia intracellularis and correlate these parameters with severity of infection based on immunohistochemistry. Sixty hamsters were equally divided into control and inoculated groups which were orally infected with intestinal mucosa homogenate from pigs naturally infected with L. intracellularis. The intestinal absorption of glucose, sodium, potassium and chloride was evaluated in live animals (25 inoculated and 25 control) on day 26 after inoculation. In this procedure, a standard solution was infused into the cranial jejunum and collected at the terminal ileum. The experimental infection was confirmed by gross and histopathological examination and L. intracellularis antigen labeling by immunohistochemistry. Histomorphometry analysis demonstrated positive correlation between intestinal crypt depth and severity of infection based on immunohistochemistry. Infected animals had significantly lower intestinal absorption of glucose, potassium and chloride. These results indicate a lower intestinal absorption as an important mechanism of diarrhea in hamsters experimentally infected with L. intracellularis. Therefore, malabsorption should be considered as the main mechanism involved in the physiopathology of the diarrhea in L. intracellularis infected animals.

Effects of sepsis-induced acute lung injury on glycogen content in different tissues

ABSTRACT The metabolic profile is very affected in sepsis, which is the most important cause of extrapulmonary acute lung injury (ALI-EX). The aim of the present study was to investigate whether sepsis-induced ALI-EX in mice affects the glycogen content in different tissues. This measurement could indicate performance limitations of tissues and constitute a novel biochemical aspect of ALI. ALI was induced by cecal ligation and puncture (CLP), which is a model that reproduces clinical and pathological alterations stemming from sepsis. Control group mice were sham-operated. Glycogen content (mg/g tissue) from different tissues was measured using the anthrone reagent. Glycogen content in the diaphragm (0.3 ± 0.1) and gastrocnemius muscle (0.4 ± 0.1) was lower in the sepsis group than the control group (0.9 ± 0.1 and 1.1 ± 0.2, respectively). However, there were no significant differences in glycogen content in the heart and kidney. Sepsis caused a greater thickening of the alveolar walls, more areas of atelectasis, and a greater abundance of inflammatory cells in comparison to the control group. These results demonstrate that glycogen content in sepsis-induced ALI-EX is altered in different tissues.

Effects of vasoactive intestinal polypeptide microinjected into the nucleus tractus solitarius on jejunal glucose absorption in rats

It has been shown that vasoactive intestinal polypeptide (VIP) injected into the nucleus tractus solitarius and into the dorsal motor nucleus of the vagus inhibits alanine absorption across the jejunum. The aim of the present study was to investigate the effects of VIP injection into the nucleus tractus solitarius on jejunal absorption of glucose in the rat. Forty Wistar rats were submitted to midline laparotomy to expose and isolate 20 cm of jejunal loop and to perform a subdiaphragmatic troncular vagotomy. Saline or VIP (10 pg 100 nl(-1)) was injected into the rostral nucleus tractus solitarius using a stereotaxic instrument. Tyrode solution, pH 8, containing twice glucose, sodium, and potassium concentrations was infused (0.5 ml min(-1)) into the jejunal loop. Samples were taken at 10-min intervals during the 40-min experiment. Injection of VIP into the nucleus tractus solitarius associated with vagotomy resulted in inhibition of jejunal glucose absorption by VIP alone at 10 and 40 min after perfusion (2.75+/-0.19 vs. 3.53+/-0.29 mg). The vagal outflow tract maintained jejunal glucose absorption even when VIP was microinjected into the nucleus tractus solitarius.

Glycogen content is affected differently in acute pulmonary and extra-pulmonary lung injury

Acute respiratory distress syndrome (ARDS) is the most severe form of acute lung injury (ALI). The aim of the present study was to investigate whether paraquat-induced acute pulmonary and extra-pulmonary lung injury (ALI-P and ALI-EX, respectively), in rats, affects glycogen content in different tissues. This measurement could indicate performance limitations of tissues, a new biochemical aspect of ARDS. ALI-P and ALI-EX were induced by injection into the trachea (0.5 mg/kg) and intraperitoneally (20 mg/kg) 24 hours prior to tissue collection. The control groups (CTRL) received the same volume of saline. Glycogen content (mg/g tissue) from different tissues was measured using the anthrone reagent. Glycogen content in the heart and kidney was higher in the ALI-EX group than the CTRL-EX group. Glycogen content in the gastrocnemius muscle was lower in the ALI-EX group than the CTRL-EX group. However, there were no significant differences in glycogen content in the diaphragm in the ALI-EX and ALI-P groups or in the gastrocnemius, heart and kidney in the ALI-P group when compared to the respective controls. ALI-EX caused a greater thickening of the alveolar walls, more areas of atelectasis and a greater abundance of inflammatory cells in comparison to ALI-P. These results demonstrate that glycogen content in ALI, induced by an herbicide that is highly toxic to humans and animals, is altered in different tissues depending on the location of the injury.

Effect of giardiasis combined with low-protein diet on intestinal absorption of glucose and electrolytes in gerbils.

Studies have shown that symptomatic infection by Giardia lamblia causes acute or chronic diarrhea, dehydration, abdominal pain and malabsorption, leading to undernutrition and weight loss. The aim of the present study was to evaluate the effects of giardiasis and its combination with a low-protein diet on the intestinal absorption of glucose and electrolytes in gerbils. The intestinal absorption of glucose, sodium and potassium was investigated in male gerbils weighing 46-64 g (n≥5). A Tyrode solution containing twice the glucose, sodium and potassium concentration (pH 7.4) was infused through the intestinal loops for 40 min. Glucose absorption was not significantly affected by diet and infection. However, there was a significant increase in sodium absorption in the Giardia-infected group (57.2±6.1, p<0.05) in comparison to the control, low-protein diet and low-protein diet+Giardia-infected groups (8.9±6.5, 2.8±11.1 and 0.8±7.9, respectively; p<0.05). Moreover, potassium was absorbed in the Giardia-infected group (0.45±0.30), while the other groups exhibited potassium secretion. A low-protein diet and Giardia infection had no influence over glucose absorption. However, Giardia infection increased sodium and potassium uptake, suggesting a compensatory mechanism for maintaining homeostasis after likely hypernatremia and hypokalemia caused by the diarrhea that accompanies giardiasis.

Effect of L-NAME microinjected into the nucleus tractus solitarius on jejunal glucose and electrolyte absorption in anesthetized rats

The aim of the present study was to investigate the effects of N(G)-nitro-L-arginine-methyl-ester (L-NAME) microinjected into the rostral nucleus tractus solitarius (NTS) on jejunal glucose, sodium and potassium absorption. Male Wistar rats (210-250 g, n=6-12) were anesthetized and submitted to midline laparotomy to expose and isolate 20 cm of jejunal loop and perform a subdiaphragmatic truncal vagotomy or sympathectomy. Either 0.9% NaCl or L-NAME (10 nmol 100 nl⁻¹) was microinjected into the rostral NTS using a stereotaxic instrument. Tyrode solution (pH 8) containing twice the usual concentrations of glucose, sodium and potassium was infused (0.5 ml min⁻¹) into the jejunal loop and samples were taken at 10-min intervals during the 40-min experiment. Results were expressed by the difference between influx and efflux. L-NAME into the NTS increased glucose absorption and decreased potassium absorption when compared to the saline group (38.8 ± 3.8 vs. 50.3 ± 3.3 mg/dl and 0.6±0.01 vs. 0.4 ± 0.03 mM, respectively; p<0.05). Sympathectomy inhibited the glucose absorption caused by L-NAME alone (50.3 ± 3.3 vs. 30.7 ± 4.6 mg/dl; p<0.05), whereas vagotomy inhibited the L-NAME effect on potassium absorption (0.40 ± 0.02 vs. 0.70 ± 0.05; p<0.05). Moreover, increased sodium absorption was observed only in the group that received 30 nmol of L-NAME into NTS (33.0 ± 4.2 vs. 48.4 ± 3.9). In conclusion, the results suggest the participation of endogenous nitric oxide (NO) in the NTS in modulating intestinal glucose and potassium absorption mediated by the autonomic nervous system.

Effects of vasoactive intestinal polypeptide microinjected into the nucleus tractus solitarius on jejunal electrolytes absorption in rats.

It has been shown that vasoactive intestinal polypeptide (VIP) injected into the nucleus tractus solitarius inhibits alanine absorption across the jejunum. The aim of the present study was to investigate the effects of VIP injection into the nucleus tractus solitarius on jejunal absorption of electrolytes in the rat. Fifty-three Wistar rats were submitted to midline laparotomy to expose and isolate 20 cm of jejunal loop and to perform a subdiaphragmatic troncular vagotomy. Saline or VIP (10 pg 100 nl(-1)) was injected into the rostral nucleus tractus solitarius using a stereotaxic instrument. Tyrode solution, pH 8, containing twice glucose, sodium and potassium concentration was infused (0.5 ml min(-1)) into the jejunal loop. Samples were taken at 10-min intervals during the 40-min-experiment. Injection of VIP into the nucleus tractus solitarius increased jejunal potassium absorption. Moreover, VIP associated with vagotomy resulted in inhibition of jejunal potassium absorption by VIP alone at 40 min after perfusion (5.99 +/- 0.74 vs. 9.83 +/- 0.57 microM). There was no change in jejunal sodium absorption in any of the experimental groups. VIP had a modulatory action on jejunal potassium absorption when injected into the nucleus tractus solitarius.

Shrimp diet and skin healing strength in rats

Forty male Wistar rats were submitted to a 4 cm dorsal skin incision and the wounds were sutured with 5-0nylon interrupted suture. The animals were divided into two groups: Group 1 (control) received a regular diet,and Group 2 (experimental) received a shrimp-enriched diet. The two diets contained the same amounts ofproteins, lipids and carbohydrates. The rats in each group were divided into two subgroups according to thetime of assessment of the scar tensile strength: subgroup A, studied on the 5

Cytokine profile of rats fed a diet containing shrimp

OBJETIVO: Estudos mostraram que a dieta suplementada com camarao reduziu a resistencia cicatricial na pele de ratos. Nesse contexto, o objetivo do presente estudo foi avaliar o perfil das citocinas de ratos que receberam dieta adicionada com camarao. METODOS: Foram comparados um grupo controle e um grupo experimental, que receberam uma dieta enriquecida com camarao (33%) durante nove dias. As duas dietas continham quantidades semelhantes de proteinas, lipideos, e carboidratos. Os niveis sericos de citocinas foram avaliados por ELISA, assim como um segmento de jejuno foi obtido para exame histologico da morfologia e infiltrado de eosinofilos. RESULTADOS: A dieta adicionada com camarao diminuiu os niveis sericos de IL-4 (14,4±1,9 versus 18,11±2,6pg/mL, p<0,05) e IL-10 (5,0±0,98 versus 7,5±1,2pg/mL, p<0,05 e aumentou os niveis sericos de IL-6 (3,2±0,4 versus 17,8±2,3pg/mL, p<0,001) quando comparada com os animais controle. Morfologicamente, a dieta adicionada com camarao causou uma desorganizacao da arquitetura da mucosa intestinal, juntamente com uma abundância de eosinofilos nas vilosidades jejunais. CONCLUSAO: Os dados sugerem que a ingestao de dieta adicionada com camarao leva a um aumento significativo da citocina IL-6, juntamente com uma diminuicao da citocina imunomoduladora IL-10 no soro de ratos e um infiltrado de eosinofilos no jejuno. O padrao inflamatorio das citocinas e o aspecto histologico do jejuno sao compativeis com alergia alimentar.