Effects of perinatal protein restriction on the oxidative balance in the hypothalamus of 60-day-old rats / Efeitos da restrição proteica perinatal sobre o balanço oxidativo no hipotálamo de ratos de 60 dias de idade

ABSTRACT Objective Evaluate the effects of maternal low-protein diet on the oxidative stress in the hypothalamus of 60-day-old rats. Methods Male Wistar rats were divided into two experimental groups according to the mother's diet during pregnancy and lactation; control group (NP:17% casein n=6) and a malnourished group (LP:8% casein n=6). At 60 days of life, the rats were sacrificed for the collection of the hypothalamus for further biochemical analysis. Results Our results showed an increase in oxidative stress in malnourished group, observed through an increase in carbonyl content (p=0.0357), a reduction in the activity of the glutathione-S-transferase enzyme (p=0.0257), and a reduction in the non-enzymatic antioxidant capacity evidenced by the decrease in the ratio reduced glutathione/oxidized glutathione (p=0.0406) and total thiol levels (p=0.0166). Conclusion A low-protein diet during pregnancy and lactation is closely associated with increased oxidative stress and reduced antioxidant capacity in the hypothalamus of sixty-day-old rats.

RESUMO Objetivo Avaliar os efeitos da restrição proteica materna sobre o estresse oxidativo no hipotálamo de ratos de 60 dias de idade. Métodos Ratos Wistar machos foram divididos em dois grupos experimentais de acordo com a dieta da mãe durante a gestação e lactação: grupo controle (NP: 17% caseína n=6) e grupo desnutrido (LP: 8% caseína n=6). Aos 60 dias de vida, os ratos foram sacrificados para coleta do hipotálamo para posterior análise bioquímica. Resultados Os resultados demonstraram aumento do estresse oxidativo no grupo desnutrido, observado através do aumento do conteúdo de cabonilas (p=0,0357) e redução da atividade da enzima glutationa-S-transferase (p=0,0257) e da capacidade antioxidante não enzimática, evidenciada pela queda da razão glutationa reduzida/glutationa oxidada (p=0,0406) e dos níveis de tióis totais (p=0,0166). Conclusão Uma dieta com baixo teor de proteínas durante a gestação e lactação está intimamente associada ao aumento do estresse oxidativo e à redução da capacidade antioxidante no hipotálamo de ratos de 60 dias de vida.

Protein malnutrition during lactation affects thoracic aortic tunica media thickness in Wistar rat pups

ABSTRACT Purpose: To evaluate the morphological effects of a low-protein diet during maternal lactation on the offspring's thoracic aorta. Methods: Two female Wistar rats were mated with male of the same species at 4 months of age. Until the birth of the pups, all animals received commercial rat chow. After giving birth, the puerperal females were divided into two groups and adjusted the litter to five puppies per group: a control group that received commercial feed, and an experimental group whose diet included the same amount of calories, but 8% lower protein content. All animals' masses were measured throughout the lactation period, and the pups were euthanized after weaning at 21 days of age. The thoracic aorta was removed, histologically processed and stained with Weigert's resorcin-fuchsin for histomorphometric analysis of tunica media thickness. Results: Although both groups were born with similar body mass, during the 21 days of lactation the restricted protein group gained only 39% of the body mass of the control group. Histomorphometric analysis revealed that the restricted protein group had a significantly lower mean tunica media thickness than the control group. Conclusions: A low-protein diet for nursing mothers influences mass gain and aortic tunica media thickness in their offspring.

High-fat diet or low-protein diet changes peritoneal macrophages function in mice

BACKGROUND: Obesity and protein malnutrition are major food problems nowadays, affecting billions of people around the world. The nutrition transition that has occurred in recent decades is changing the nutritional profile, reducing malnutrition and increasing the percentage of obese people. The innate immune response is greatly influenced by diet, with significant changes in both malnutrition and obesity. Therefore, we investigate the effects of protein malnutrition and obesity in nutritional and immunological parameters in mice. RESULTS: Peritoneal macrophages of malnourished animals showed reduced functions of adhesion, spreading, and fungicidal activity; production of hydrogen peroxide and nitric oxide were lower, reflecting changes in the innate immune response. However, the high-fat animals had macrophage functions slightly increased. CONCLUSIONS: Animals subjected to low-protein diet have immunosuppression, and animals subjected to high-fat diet increased visceral adipose tissue and the presence of an inflammatory process with increased peritoneal macrophage activity and similar systemic changes to metabolic syndrome.

Maternal malnutrition diet during lactation period leads to incomplete catch-up growth in femur of the pups at adulthood / Restricción alimentaria materna durante la lactancia conduce a la recuperación del crecimiento incompleto en el fémur de las crías en la edad adulta

The aim of this study was to evaluate the effects of maternal protein and energy restriction during lactation, analyzing on morphological dimensions whether there was catch-up growth through normative nutrition restored, as well as on mechanical axis of femur of the offspring at adulthood. At parturition, Wistar rat dams were randomly assigned to the following groups: 1) control group (C) - free access to a standard laboratory diet containing 23 % protein, 2) protein-energy restricted group (PER) - free access to an isoenergetic, protein-restricted diet containing 8 % protein, and 3) energy-restricted group (ER) ­ fed with restricted amounts of a standard laboratory diet. At weaning, all pups were separated of dams and received free access to a standard laboratory diet containing 23 % protein until 180 days, when the rats were anesthetized and sacrificed. The dimensions of excised pup femur were measured directly using pre-established anatomical points. Morphometric analysis of the femur (macroscopic) showed that most of the measurements in the ER and PER groups were significantly lower than in the control group, with the greatest reductions occurring in the PER group and several structural abnormalities. Our results show that protein and energy restriction during lactation leads to an incomplete catch-up growth in adulthood. The femur showed significant reduction in most of the parameters in the two treated groups, particularly the PER group, when compared to the control group.

El objetivo de este estudio fue evaluar los efectos de la restricción de la proteína materna y de energía durante la lactancia, y analizar las dimensiones morfológicas si hubo recuperación del crecimiento a través de la nutrición normativa restaurada, así como en el eje mecánico del fémur de la descendencia en la edad adulta. En el parto, las crías de ratas Wistar fueron agrupadas aleatoriamente en los siguientes grupos: 1) control (C) - con acceso libre a una dieta estándar del laboratorio, que contenía 23 % de proteínas; 2) con restricción de proteínas y energía (PER) - acceso libre a una dieta isoenergética, con restricción de proteínas, conteniendo un 8 % de éstas y 3) grupo con restricción de energía, alimentado con restricción en la cantidad de alimento de la dieta estándar del laboratorio (ER). Al destete, todas las crías fueron separadas y recibieron las dietas establecidas hasta los 180 días (d180), luego fueron anestesiadas y sacrificadas. Las mediciones de los fémures de las crías de rata fueron obtenidas por puntos anatómicos preestablecidos. El análisis morfométrico de fémur demostró que la mayoría de las mediciones en los grupos ER y PER eran significativamente menores que las del grupo control, con mayores reducciones en el grupo PER. Nuestros resultados muestran que las restricciones de energía y proteínas durante la lactancia conducen a una recuperación del crecimiento incompleto en la edad adulta. El fémur mostró una reducción significativa en la mayoría de los parámetros en los dos grupos tratados, en particular el grupo de PER, en comparación con el grupo control.

Desnutrição materna durante a lactação em ratos Wistar: efeitos sobre as fibras elásticas da matriz extracelular na traqueia dos filhotes / Maternal malnutrition during lactation in Wistar rats: effects on elastic fibers of the extracellular matrix in the trachea of offspring

OBJETIVO: Investigar os efeitos da desnutrição proteica materna durante a lactação sobre as fibras elásticas da traqueia de filhotes de ratos Wistar. MÉTODOS: Ao nascimento, 12 filhotes machos de duas ratas Wistar foram igualmente divididos em dois grupos: grupo controle, cuja mãe recebeu água e dieta padrão de laboratório ad libitum durante a lactação, e grupo restrição proteica (RP), cuja mãe recebeu água ad libitum e dieta isoenergética com RP (8% de proteína). Aos 21 dias de vida, os filhotes foram sacrificados, e suas traqueias foram ressecadas. As fibras elásticas foram coradas pelo método de resorcina-fucsina de Weigert (precedido de oxidação) e avaliadas sob microscopia óptica. As determinações morfométricas foram feitas por estereologia, utilizando o método de contagem de pontos, e expressas em densidade volumétrica. RESULTADOS: As fibras elásticas foram identificadas abaixo da mucosa traqueal, sendo a maioria em distribuição longitudinal. Além disso, camadas circulares bem definidas de fibras elásticas envolviam as superfícies interna e externa do anel cartilaginoso. Não houve diferenças entre os grupos quanto à organização e distribuição das fibras elásticas. A densidade volumétrica das fibras elásticas dos filhotes nos grupos controle e RP foi de, respectivamente, 2,46 ± 0,99% e 3,25 ± 1,13% (p < 0,01). CONCLUSÕES: Nossos resultados sugerem que a densidade volumétrica de fibras elásticas é maior em filhotes de ratos alimentados por fêmeas submetidas a dieta com RP do que naqueles de mães recebendo dieta normal.

OBJECTIVE: To investigate the effects of maternal protein malnutrition during lactation on the elastic fibers in the tracheas of Wistar rat pups. METHODS: At delivery, 12 male pups of two Wistar rat dams were equally divided into two groups: control, in which the dam received water and standard rat chow ad libitum during lactation; and protein-restricted (PR), in which the dam received water ad libitum and an isoenergetic PR diet (8% protein). At 21 days of age, the pups were killed and their tracheas were excised. The elastic fibers were stained with Weigert's resorcin-fuchsin (after oxidation) and evaluated under light microscopy. Morphometric determinations were performed by stereology, with the point-counting method, and expressed as volumetric densities. RESULTS: Elastic fibers, most having a longitudinal distribution, were identified beneath the tracheal mucosa. In addition, well-defined circular layers of elastic fibers were found around the inner and outer surfaces of the cartilaginous ring. There were no differences between the groups regarding the organization and distribution of the elastic fibers. The volumetric density of the elastic fibers of the pups in the control and PR groups was 2.46 ± 0.99% and 3.25 ± 1.13%, respectively (p < 0.01). CONCLUSIONS: The volumetric density of elastic fibers appears to be greater in rat pups breastfed by dams receiving a PR diet than in those breastfed by dams receiving a normal diet.

The outcome of acute schistosomiasis infection in adult mice with postnatal exposure to maternal malnutrition

Maternal malnutrition during the lactation period in early development may have long-term programming effects on adult offspring. We evaluated the combined effects of parasitological behaviour and histopathological features and malnutrition during lactation. Lactating mice and their pups were divided into a control group (fed a normal diet of 23 percent protein), a protein-restricted group (PR) (fed a diet containing 8 percent protein) and a caloric-restricted group (CR) (fed according to the PR group intake). At the age of 60 days, the offspring were infected with Schistosoma mansoni cercariae and killed at nine weeks post-infection. Food intake, body and liver masses, leptinaemia, corticosteronaemia, collagen morphometry and neogenesis and the cellular composition of liver granulomas were studied. PR offspring showed reduced weight gain and hypophagia, whereas CR offspring became overweight and developed hyperphagia. The pre-patent period was longer (45 days) in both programmed offspring as compared to controls (40 days). The PR-infected group had higher faecal and intestinal egg output and increased liver damage. The CR-infected group showed a lower number of liver granulomas, increased collagen neogenesis and a higher frequency of binucleate hepatocytes, suggesting a better modulation of the inflammatory response and increased liver regeneration. Taken together, our findings suggest that neonatal malnutrition of offspring during lactation affects the outcome of schistosomiasis in mice.

Maternal Food Restriction During Lactation Reduces Mandible Growth of the Female Offspring in Adulthood: Experimental and Morphometric Analysis / Restricción Alimentaria Materna Durante la Lactancia Reduce el Crecimiento de la Mandíbula de las Crías Hembras en la Edad Adulta: Análisis Experimental y Morfométrico

The aim of this study was to evaluate the effects of maternal protein and energy restriction during lactation on mandible dimensions of pups (female) at aging. At parturition, Wistar rat dams were randomly assigned to the following groups: 1) control group (C) - free access to a standard laboratory diet containing 23 percent protein, 2) protein-energy restricted group (PER) - free access to an isoenergetic, protein-restricted diet containing 8 percent protein, and 3) energy-restricted group (ER) ­ fed with restricted amounts of a standard laboratory diet. At weaning (d21), all pups were separated of dams and received free access to a standard laboratory diet containing 23 percent protein until 90 days (d90), when the rats were anesthetized and sacrificed. The dimensions of excised pup mandible were measured directly using pre-established 3 anatomical points. Morphometric analysis showed that most of the measurements in the ER and PER groups were significantly lower than in the control group, with the greatest reductions occurring in the PER group. These results show that protein and energy restriction during lactation have an important influence on pup mandible development and continue through the aging process.

El objetivo de este estudio fue evaluar los efectos de la restricción de la proteína materna y de la energía durante la lactancia sobre las dimensiones de la mandíbula de crías (hembras) durante la vida. En el parto, las crías de ratas Wistar fueron agrupadas aleatoriamente en los siguientes grupos: 1) control (C) - con acceso libre a una dieta estándar del laboratorio, que contenía 23 por ciento de proteínas; 2) con restriccion de proteínas y energía (PER) - acceso libre a una dieta isoenergética, con restricción de proteínas, conteniendo un 8 por ciento de éstas y 3) grupo con restricción de energía, alimentado con restricción en la cantidad de alimento de la dieta estándar del laboratorio (ER). Al destete, todas las crías fueron separadas y recibieron las dietas establecidas hasta los 90 días (d90), luego fueron anestesiadas y sacrificadas. Las mediciones de las mandíbulas de las crías de rata fueron obtenidas por 3 puntos anatómicos preestablecidos. El análisis morfométrico de la mandíbula demostró que la mayoría de las mediciones en los grupos ER y PER eran significativamente menores que las del grupo control, con mayores reducciones en el grupo PER. Estos resultados muestran que las restricciones de energía y proteínas durante la lactancia tienen una influencia importante en el desarrollo de la mandíbula de las crías, las que se mantuvieron con el paso del tiempo.

Restrição proteica materna e alteração do desenvolvimento das artérias coronárias em camundongos / Maternal protein restriction and alteration of the development of coronary arteries in mice

O desenvolvimento da programação fetal é considerado um importante fator de risco para doenças não-transmissíveis da vida adulta, incluindo doença cardíaca coronariana. Com o objetivo de investigar a associação entre nutrição materna e o desenvolvimento das artérias coronárias (AC) em embriões de camundongos estadiados; embriões de camundongos C57BL/6 nos estádios de 16-23 foram retirados de mães alimentadas com dietas de proteína normal (NP) ou de baixa proteína (LP), e as AC foram estudadas. Embora os embriões LP possuam massa corporal menor, entretanto tinham taxas de crescimento cardíaco maior, quando comparados com os embriões NP. O Plexo subepicárdico foi observado no início do período pós-somítico (estádio 16) em embriões NP, enquanto que nos embriões LP apenas no estádio 17 (P <0,01), persistindo até o estádio 18 (P <0,01). As artérias coronárias foram detectadas inicialmente no estádio 18 dos embrioes NP, já nos embriões LP foram encontradas a partir do estádio 19 (P <0,01). Núcleos apoptóticos foram observados em torno do anel aórtico peritruncal no estádio 18 em embriões NP e LP. Células FLK1+ (Fetal Liver Kinase 1 = VEGFr2 = Vascular Endothelial Growth Factor Receptor 2) apresentaram uma distribuição homogênea nos embriões NP já no estádio 18, enquanto uma distribuição semelhante nos embriões LP foi visto apenas nos estádios 22 e 23. A restrição proteica materna em camundongos leva a um atraso no crescimento do coração no período embrionário modificando o desenvolvimento do plexo peritruncal subepicárdica e diminuindo a taxa de apoptose na região do futuro orifício coronariano

Programming of fetal development is considered to be an important risk factor for non-communicable diseases of adulthood, including coronary heart disease (CHD). Aiming to investigate the association between maternal nutrition and the development of the coronary arteries (CA) in staged mice embryos, C57BL/6 mice embryos from stages 16 to 23 were taken from mothers fed a normal protein (NP) or low protein (LP) diet, and the CA were studied. Although the LP embryos had lower masses, they had faster heart growth rates when compared to the NP embryos. The subepicardial plexuses were observed earlier in the NP embryos (stage 20) than in the LP ones (stage 22) (P<0.01). Apoptotic nuclei were seen around the aortic peritruncal ring beginning at stage 18 in the NP and LP embryos. FLK1+ (fetal liver kinase 1 = VEGFr2 or vascular endothelial growth factor receptor 2) cells had a homogeneous distribution in the NP embryos as early as stage 18, whereas a similar distribution in the LP embryos was only seen at stages 22 and 23. Maternal protein restriction in mice leads to a delay in the growth of the heart in the embryonic period modifying the development of the subepicardial peritruncal plexus and the apoptosis in the future coronary orifice region

Maternal undernutrition and the offspring kidney: from fetal to adult life

Maternal dietary protein restriction during pregnancy is associated with low fetal birth weight and leads to renal morphological and physiological changes. Different mechanisms can contribute to this phenotype: exposure to fetal glucocorticoid, alterations in the components of the renin-angiotensin system, apoptosis, and DNA methylation. A low-protein diet during gestation decreases the activity of placental 11ß-hydroxysteroid dehydrogenase, exposing the fetus to glucocorticoids and resetting the hypothalamic-pituitary-adrenal axis in the offspring. The abnormal function/expression of type 1 (AT1R) or type 2 (AT2R) AngII receptors during any period of life may be the consequence or cause of renal adaptation. AT1R is up-regulated, compared with control, on the first day after birth of offspring born to low-protein diet mothers, but this protein appears to be down-regulated by 12 days of age and thereafter. In these offspring, AT2R expression differs from control at 1 day of age, but is also down-regulated thereafter, with low nephron numbers at all ages: from the fetal period, at the end of nephron formation, and during adulthood. However, during adulthood, the glomerular filtration rate is not altered, due to glomerulus and podocyte hypertrophy. Kidney tubule transporters are regulated by physiological mechanisms; Na+/K+-ATPase is inhibited by AngII and, in this model, the down-regulated AngII receptors fail to inhibit Na+/K+-ATPase, leading to increased Na+ reabsorption, contributing to the hypertensive status. We also considered the modulation of pro-apoptotic and anti-apoptotic factors during nephrogenesis, since organogenesis depends upon a tight balance between proliferation, differentiation and cell death.

Passive stiffness of rat skeletal muscle undernourished during fetal development

OBJECTIVES: The aim of the study was to investigate the effect of fetal undernutrition on the passive mechanical properties of skeletal muscle of weaned and young adult rats. INTRODUCTION: A poor nutrition supply during fetal development affects physiological functions of the fetus. From a mechanical point of view, skeletal muscle can be also characterized by its resistance to passive stretch. METHODS: Male Wistar rats were divided into two groups according to their mother's diet during pregnancy: a control group (mothers fed a 17 percent protein diet) and an isocaloric low-protein group (mothers fed a 7.8 percent protein diet). At birth, all mothers received a standardized meal ad libitum. At the age of 25 and 90 days, the soleus muscle and extensor digitorum longus (EDL) muscles were removed in order to test the passive mechanical properties. A first mechanical test consisted of an incremental stepwise extension test using fast velocity stretching (500 mm/s) enabling us to measure, for each extension stepwise, the dynamic stress (σd) and the steady stress (σs). A second test consisted of a slow velocity stretch in order to calculate normalized stiffness and tangent modulus from the stress-strain relationship. RESULTS: The results for the mechanical properties showed an important increase in passive stiffness in both the soleus and EDL muscles in weaned rat. In contrast, no modification was observed in young adult rats. CONCLUSIONS: The increase in passive stiffness in skeletal muscle of weaned rat submitted to intrauterine undernutrition it is most likely due to changes in muscle passive stiffness.

Restrição protéica na prenhez: efeitos relacionados ao metabolismo materno / Protein restriction in pregnancy: effects related to dam metabolism

Foram avaliadas as alterações no metabolismo materno durante a prenhez em ratas Wistar, prenhes e não-prenhes, submetidas à restrição protéica, que receberam dietas isocalóricas (15,74 kJ/g), controle ou hipoprotéica (17 por cento versus 6 por cento), distribuídas em quatro grupos (n = 7), quais sejam: controle não-prenhe (CNP) e prenhe (CP) e hipoprotéico não-prenhe (HNP) e prenhe (HP), do 1º ao 18º dia de prenhez. Parâmetros bioquímicos, hormonais e relacionados à síntese de lipídios foram considerados. Utilizou-se ANOVA a duas vias seguido de teste Tukey-HSD e teste t de Student, significância de p < 0,05. A restrição protéica elevou a síntese de lipídios e a atividade da enzima málica (EM) no fígado (FIG) e reduziu a massa ( por cento) e a razão lipí+dio/glicogênio nesse tecido, bem como reduziu a ingestão protéica (total e por cento), o conteúdo ( por cento) de lipídios na glândula mamária (GMA), as proteínas e a albumina séricas, com consequente redução nas massas da placenta e fetos. A prenhez reduziu a proteinemia, a albuminemia, a síntese de lipídios, a atividade da EM, os lipídios e o glicogênio no FIG. Mas elevou a massa corporal final, a massa ( por cento) do tecido adiposo gonadal (GON), do FIG e da GMA, e reduziu a massa ( por cento) da carcaça (CARC), a síntese e o conteúdo de lipídios no GON e, na GMA, o conteúdo de lipídios. A insulinemia elevou-se na prenhez, com glicemia reduzida, caracterizando resistência hormonal. A leptina e a prolactina também se elevaram na prenhez, sendo o aumento maior no HP. A restrição protéica na prenhez modificou o metabolismo materno, alterando a síntese de lipídios no FIG e o perfil hormonal, além de reduzir a massa da placenta e dos fetos.

Metabolism alterations were evaluated in female Wistar rats (dams) during pregnancy. Pregnant and non-pregnant dams submitted to protein restriction, were fed isocaloric (15.74 kJ/g), control or hypoproteic (17 percent vs. 6 percent) diets, and distributed in four Groups (n=7) as follows: non-pregnant control (NPC), pregnant control (PC), non-pregnant hypoproteic (NPH), and pregnant hypoproteic (PH); from Day 1 to Day 18 of pregnancy. Biochemical, hormonal and metabolic parameters related to lipid synthesis were assessed. The two-way ANOVA, followed by Tukey-HSD and Student-t tests were used, with a significance of p< 0.05. Protein restriction elevated lipid synthesis and malic enzyme (ME) activity in the liver, and reduced mass and the lipid/glycogen ratio in this tissue; it also lowered protein ingestion (total and percent), lipid content ( percent) in the mammary gland (MAG), serum proteins and albumin, with consequent reduction of placenta and fetal masses. Pregnancy reduced serum protein and albumin concentrations, lipid synthesis, ME activity, hepatic lipid and glycogen content. However, it increased final body mass; increased relative masses of gonad (GON), liver and MAG; but reduced lipid synthesis and content of GON, lipid content of MAG and the relative mass of carcass. Pregnancy Insulinemia increased during pregnancy with reduced glycemia, characterizing hormonal resistance. Leptin and prolactin were also increased during pregnancy, being the highest increase in observed in HP rats. Protein restriction in pregnancy modified maternal metabolism, altering lipid synthesis in the liver and hormonal profile and decreasing the placenta and fetus masses.

Effect of nicotine on lipid profile, peroxidation & antioxidant enzymes in female rats with restricted dietary protein.

BACKGROUND & OBJECTIVE: Nicotine intake through tobacco is very common in female population of lower socioeconomic level who are deprived of healthy diet. Women suffer consequences of smoking such as cardiovascular disorder, lung related diseases and oxidative stress, etc. No data are available of the influences of nicotine on lipid profile, lipid peroxidation and antioxidant enzymes levels under restricted dietary protein intake. The present study was carried out to investigate the effect of nicotine on such parameters of female rats fed with protein restricted diet (5% casein) as compared to those with normal protein diet (18% casein) with or without vitamin C or E supplementation. METHODS: Subcutaneous injections of nicotine tartrate (3.5 mg/kg body weights per day for 15 days) were given to the rats and subsequent measurements of plasma lipid profile, plasma and ovary lipid peroxidation and antioxidant enzymes were done. RESULTS: The results showed significant (P<0.01) increase of total cholesterol (TC) and more significant (P<0.001) increase of triglyceride and low-density lipoprotein cholesterol (LDL-C) of plasma under both dietary conditions. The increase of plasma very low-density lipoprotein cholesterol (VLDL-C) was highly significant under protein-restricted diet. The high-density lipoprotein cholesterol (HDLC) decreased significantly in both dietary conditions. Lipid peroxidation in plasma increased significantly in protein-restricted condition. Superoxide dismutase and catalase activities in the ovary tissue decreased significantly (P<0.001) by nicotine treatment in both dietary groups. INTERPRETATION & CONCLUSION: Our findings indicated that nicotine-induced toxicity is more in lipid profile (plasma) and lipid peroxidation (plasma and ovary tissue) under protein-restricted diet as compared to that of the normal protein diet. The antioxidant vitamins antagonized the nicotineinduced effects less effectively on the observed parameters under restricted dietary protein.

Impacto de la dieta sobre la inducción de infección con quistes de Giardia lamblia en ratas Sprague-Dawley / Impact of diet on the induction of infection with Giardia lamblia cysts in Sprague-Dawley rats

OBJECTIVE: To assess the effect of malnutrition on the development of giardiasis in Sprague-Dawley rats, using different inoculum sizes of Giardia lamblia cysts. MATERIAL AND METHODS: An experimental study was conducted between 1995 and 1999 at Centro de Investigación, Alimentación y Desarrollo (Center for Research, Food, and Development), in Hermosillo, Sonora, Mexico. The study population consisted of two groups of six to eight experimental units that were fed two different diets and inoculated five different concentrations of Giardia lamblia cysts. Data were collected on excretion of cysts, weight gain, food intake, bowel contents, and macro and microscopic lesions in the intestinal mucosa. Statistical analysis consisted of analysis of variance and residuals. RESULTS: Animals fed with a diet meeting nutritional requirements required an infecting inoculum of 60 cysts, while malnourished rats required only six cysts to develop mucosal lesions. CONCLUSIONS: Weight gain monitored during ten days was not a good indicator of Giardia lamblia infection. Infection depended on cyst inoculum size as well as on the nutritional status of the tested animals.

Comportamento alimentar de ratos adultos submetidos à restrição protéica cujas mães sofreram desnutrição durante a lactação / Feeding behavior of adult rats submitted to protein malnutrition whose members received protein restricted diets during lactation

Foi avaliado o consumo alimentar de animais adultos submetidos à restrição protéica, cujas mães receberam dieta hipoprotéica ou hipocalórica na lactação: controle (C) ração normal com 23 por cento de proteína; restrição protéica (RP) 8 por cento de proteína; restrição energética (RE) 23 por cento de proteína, em quantidade restrita à ingerida pelo grupo restrição protéica. Após o desmame todos os filhotes receberam ração normal até 60 dias e nesta época foram submetidos, por 21 dias, ao seguinte tratamento: (C/C)-filhotes de mães C recebendo ração normal; (restrição protéica/controle)-filhotes de mães Controle, recebendo ração hipoprotéica; (C/RP)-filhotes de mães RP recebendo ração normal; (RP/RP)-filhotes de mães RP recebendo ração hipoprotéica; (C/RE)-filhotes de mães RE recebendo ração normal; (RP/RE)-filhotes de mães RE recebendo ração hipoprotéica. Os filhotes de mães RP consumiram menos ração até 57 dias (p<0,01), enquanto os filhotes de mães RE normalizaram a ingestão aos 37 dias. Aos 81 dias, os animais submetidos à restrição protéica consumiram menos ração (p<0,01). A dieta materna na lactação modificou o consumo alimentar e o peso corporal da prole na vida adulta, estando, possivelmente, a restrição protéica associada a uma alteração permanente no controle hipotalâmico da seleção de nutrientes da prole

Effect of feeding protein deficient diet on phospholipid turnover and protein kinase C mediated protein phosphorylation in rat brain.

Feeding of protein deficient diet is known to alter the transmembrane signalling in brain of rat by reducing total protein kinase C (PKC) activity. Phospholipid metabolism regulates the activation of PKC through generation of second messengers and the extent of PKC activation accordingly influences the magnitude of phosphorylation of its endogenous substrate proteins. Thus it was speculated that ingestion of protein deficient diet may modify the turnover rate of membrane phospholipids and magnitude of phosphorylation of endogenous substrate proteins of PKC. The experiments were conducted on rats fed on three different types of laboratory prepared diets viz. casein (20% casein), deficient (4% protein, rice flour as source of protein) and supplemented (deficient diet supplemented with L-lysine and DL-threonine) for 28 days. The metabolism of phosphoinositides (PIs) and phosphatidyl choline (PC) was studied by equilibrium labeling with [3H] myo inositol and [14C methyl] choline chloride respectively. The phosphorylation of endogenous substrate proteins of PKC was studied by using 32P-gamma-ATP followed by SDS-PAGE and autoradiography. The results suggest that in deficient group, there is an increased incorporation of [3H] myo inositol in PIs and inositol phosphate pool in comparison to the casein group. The phosphatidyl inositol (PI) turnover reduced, although there was a marginal increase in the phosphatidyl inositol monophosphate (PIP) and phosphatidyl inositol bis phosphate (PIP2). Supplementation of diet showed a reversal of the pattern towards control to a considerable extent. In the deficient group, PC metabolism showed an increased incorporation of [14C methyl] choline in choline phospholipids but decreased incorporation in phosphoryl choline in comparison with the casein group. The increase in total PC contents was significant but marginal in residue contents. The turnover rate of PC increased only marginally and that of residue declined. Supplementation of diet reduced the total contents of PC and residue, but the turnover rate of PC and residue remained still higher. Phosphorylation of endogenous proteins showed four different proteins of 78, 46, 33 and 16 kDa to be the substrates of PKC in casein group. In deficient group, phosphorylation of these proteins increased markedly while supplementation of diet had a reversing effect rendering the values to be intermediate between casein and the supplemented group. The changes in phospholipid metabolism and in phosphorylation of endogenous substrate proteins of PKC suggest that dietary protein deficiency causes alterations in transmembrane signalling mechanism in rat brain. These effects are partially reversed by improving the quality of proteins in the diet.

Deficiencia proteica: impacto sobre el timo de ratas en crecimiento / Protein deficiency: effect of thymus of growing rats

Se analiza las consecuencias provocadas por desequilibrios nutricionales sobre el contenido de DNA y la actividad de las enzimas ADA y PNP en timo de ratas en crecimientos. Ratas Wistar al destete fueron alimentadas con: 1- dieta libre de proteínas hasta asemejar cuadros de malnutrición proteica leve, moderada y severa; 2- dieta conteniendo harina de maíz en baja concentración (6,5 por ciento). La subnutrición durante la lactancia se obtuvo duplicando la camada (12-14 crías por madre). Como controles se utilizaron ratas bien nutridas de igual edad, que desde el destete recibieron dieta stock. Al finalizar la experiencia, se les extrajo el timo (Pt)(mg). Se determinó DNA (mg/órgano), el número de núcleos, el tamaño celular- Pt(mg)/No. de Núcleos- y la actividad de las enzimas ADA y PNP (umol de ácido úrico x 10 - 1/P)(P=Pt(mg) /P corporal 0.75). Los resultados muestran que tanto la subnutrición durante la lactancia, como la malnutrición proteica al destete y la administración de dieta de baja calidad, afectan la proliferación celular en el timo, Sólo la carencia de proteína o su baja calidad, aumenta la actividad de ADA y PNP