Effect of lung fibrosis on glycogen content in different extrapulmonary tissues.

PURPOSE: Patients with pulmonary fibrosis often exhibit reduced lung function and diminished health-related quality of life. Studies have shown that paraquat-induced, extrapulmonary, acute lung injury affects the metabolic profile of glycogen content in different tissues. The purpose of the present study was to investigate whether the process of pulmonary fibrosis induced by continuous exposure to the toxic herbicide paraquat or by a local insult from bleomycin affects the glycogen content in tissues. METHODS: In the paraquat experiment, Wistar rats (n = 5 per group) received either saline (controls) or an intraperitoneal injection of a paraquat solution (7.0 mg/kg; experimental group) once a week for 4 weeks. In the bleomycin experiment, Balb/c mice (n = 5 per group) received either saline (controls) or 6.25 U/kg of bleomycin through intratracheal instillation in single dose (experimental group). Glycogen content in different tissues (mg/g tissue) was measured using the anthrone reagent. The lungs submitted to histopathological and quantitative analyses of fibrosis. RESULTS: Paraquat-induced fibrosis led to lower glycogen content in the gastrocnemius muscle (2.7 ± 0.1 vs. 3.4 ± 0.1; 79 %) compared with the controls, whereas no changes in glycogen content were found in the diaphragm or heart. Bleomycin-induced fibrosis led to lower glycogen content in the diaphragm (0.43 ± 0.02 vs. 0.79 ± 0.09, 54 %), gastrocnemius muscle (0.62 ± 0.11 vs. 1.18 ± 0.06, 52 %), and heart (0.68 ± 0.11 vs. 1.39 ± 0.1, 49 %) compared with the controls (p < 0.05). Moreover, the area of fibrous connective tissue (µm(2)) in the lungs was significantly increased in paraquat-induced fibrosis (3,463 ± 377 vs. 565 ± 89) and bleomycin-induced fibrosis (3,707 ± 433.9 vs. 179 ± 51.28) compared with the controls. CONCLUSIONS: The findings suggest that the effects of fibrogenesis in the lungs are not limited to local alterations but also lead to a reduction in glycogen content in the heart and other muscles. This reduction could partially explain the impaired muscle performance found in patients with pulmonary fibrosis.

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.

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.

Cytokine profile of rats fed a diet containing shrimp / Perfil das citocinas de ratos alimentados com dieta de camarão

OBJECTIVE: Studies have shown that shrimps reduced the tensile strength of scars in rat skin. The aim of the present study was to assess the cytokine profile of rats fed shrimp. METHODS: Group 1 (control) received a regular diet and Group 2 (experimental) received a diet containing 33% shrimp for nine days. The two diets contained the same amounts of proteins, fats and carbohydrates. Serum cytokine levels were determined by ELISA and a segment of the jejunum was taken to investigate its histological morphology and eosinophil infiltrate. RESULTS: The experimental group had lower serum levels of interleukin-4 (IL-4) (14.4±1.9 versus 18.11±2.6pg/mL; p<0.05) and IL-10 (5.0±0.98 versus 7.5±1.2pg/mL; p<0.05) and higher levels of IL-6 (17.8±2.3 versus 3.2±0.4pg/mL, p<0.001) than controls. Morphologically, the shrimp-based diet caused an architectural disorganization of the intestinal mucosa and a greater amount of eosinophils in the jejunal villus. CONCLUSION: Our data suggests that shrimp consumption leads to a significant increase in the cytokine IL-6, a decrease in the immunomodulatory cytokine IL-10 in the serum of rats, and high eosinophil infiltration in the jejunum. The cytokine profile typical of inflammation and the histological aspect of the jejunum are compatible with food allergy.

OBJETIVO: Estudos mostraram que a dieta suplementada com camarão reduziu a resistência 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 camarão. MÉTODOS: Foram comparados um grupo controle e um grupo experimental, que receberam uma dieta enriquecida com camarão (33%) durante nove dias. As duas dietas continham quantidades semelhantes de proteínas, lipídeos, e carboidratos. Os níveis séricos de citocinas foram avaliados por ELISA, assim como um segmento de jejuno foi obtido para exame histológico da morfologia e infiltrado de eosinófilos. RESULTADOS: A dieta adicionada com camarão diminuiu os níveis séricos 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 níveis séricos 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 camarão causou uma desorganização da arquitetura da mucosa intestinal, juntamente com uma abundância de eosinófilos nas vilosidades jejunais. CONCLUSÃO: Os dados sugerem que a ingestão de dieta adicionada com camarão leva a um aumento significativo da citocina IL-6, juntamente com uma diminuição da citocina imunomoduladora IL-10 no soro de ratos e um infiltrado de eosinófilos no jejuno. O padrão inflamatório das citocinas e o aspecto histológico do jejuno são compatíveis com alergia alimentar.

Shrimp diet and skin healing strength in rats

OBJECTIVE: Surgical scar tensile strength may be influenced by several factors such as drugs, hormones and diet. The purpose of the present study was to determine the influence of a shrimp-enriched diet on the tensile strength of rat scars. METHODS: Forty male Wistar rats were submitted to a 4 cm dorsal skin incision and the wounds were sutured with 5-0 nylon 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 of proteins, lipids and carbohydrates. The rats in each group were divided into two subgroups according to the time of assessment of the scar tensile strength: subgroup A, studied on the 5th postoperative day, and subgroup B, studied on the 21st postoperative day. RESULTS: The tensile strength of the scar on the 5th postoperative day was lower in the animals that received the shrimp-enriched-diet (303.0, standard error of mean= 34.1) than in the control group (460.1, SEM = 56.7) (p<0.05). CONCLUSION: A shrimp diet reduces the tensile strength of the scar. The next step of this study will be to clarify the mechanism in which shrimp affects tensile strength.

OBJETIVO: A resistência cicatricial da pele pode ser influenciada por diversos fatores como medicamentos, hormônios e dieta. Este trabalho foi delineado para determinar a influência da dieta com camarão na resistência cicatricial na pele. MÉTODOS: Quarenta ratos machos Wistar foram submetidos a incisão (4cm) e suturas interrompidas da pele dorsal, com fio de nylon 5-0, e foram divididos em dois grupos: o Grupo 1 (controle) recebeu uma dieta convencional e Grupo 2 (experimental), recebeu dieta com adição de com camarão. As duas dietas continham quantidades semelhantes de proteína, lipídeos, e carboidratos. Os ratos de cada grupo foram divididos em dois subgrupos de acordo com os distintos períodos pós-operatórios de avaliação da resistência tecidual: subgrupo A, estudado no 5° dia pós-operatório, e subgrupo B, estudado no 21° dia pós-operatório. RESULTADOS: A resistência cicatricial da pele no 5° dia pós-operatório foi menor nos animais que receberam dieta suplementada com camarão (303,0, erro padrão da média=34,1), quando comparada ao grupo controle (460,1, erro padrão=56,7) (p<0,05). CONCLUSÃO: A dieta suplementada com camarão reduziu a resistência cicatricial da pele de ratos. Dando continuidade ao estudo, será averiguado o mecanismo pelo qual ocorre essa redução.