Maria Salete Ferreira Martins

Low-Protein Diet during Lactation and Maternal Metabolism in Rats

Some metabolic alterations were evaluated in Wistar rats which received control or low-protein (17%; 6%) diets, from the pregnancy until the end of lactation: control non-lactating (CNL), lactating (CL), low-protein non-lactating (LPNL) and lactating (LPL) groups. Despite the increased food intake by LPL dams, both LP groups reduced protein intake and final body mass was lower in LPL. Higher serum glucose occurred in both LP groups. Lactation induced lower insulin and glucagon levels, but these were reduced by LP diet. Prolactin levels rose in lactating, but were impaired in LPL, followed by losses of mammary gland (MAG) mass and, a fall in serum leptin in lactating dams. Lipid content also reduced in MAG and gonadal white adipose tissue of lactating and, in LPL, contributed to a decreased daily milk production, and consequent impairment of body mass gain by LPL pups. Liver mass, lipid content and ATP-citrate enzyme activity were increased by lactation, but malic enzyme and lipid: glycogen ratio elevated only in LPL. Conclusion. LP diet reduced the development of MAG and prolactin secretion which compromised milk production and pups growth. Moreover, this diet enhanced the store of lipid to glycogen ratio and suggests a higher risk of fatty liver development.

Protein restriction in pregnancy: effects related to dam metabolism

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% vs. 6%) 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 %), lipid content (%) 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.

Intrauterine protein restriction combined with early postnatal overfeeding was not associated with adult-onset obesity but produced glucose intolerance by pancreatic dysfunction

We investigated if whether intrauterine protein restriction in combination with overfeeding during lactation would cause adult-onset obesity and metabolic disorders. After birth, litters from dams fed with control (17% protein) and low protein (6% protein) diets were adjusted to a size of four (CO and LO groups, respectively) or eight (CC and LC groups, respectively) pups. All of the offspring were fed a diet containing 12% protein from the time of weaning until they were 90 d old. Compared to the CC and LC groups, the CO and LO groups had higher relative and absolute food intakes, oxygen consumption and carbon dioxide production; lower brown adipose tissue weight and lipid content and greater weight gain and absolute and relative white adipose tissue weight and absolute lipid content. Compared with the CO and CC rats, the LC and LO rats exhibited higher relative food intake, brown adipose tissue weight and lipid content, reduced oxygen consumption, carbon dioxide production and spontaneous activity, increased relative retroperitoneal adipose tissue weight and unaltered absolute white adipose tissue weight and lipid content. The fasting serum glucose was similar among the groups. The area under the glucose curve was higher in the LO and CO rats than in the LC and CC rats. The basal insulinemia and homeostasis model assessment of insulin resistance (HOMA-IR) were lower in the LO group than in the other groups. The total area under the insulin curve for the LO rats was similar to the CC rats, and both were lower than the CO and LC rats. Kitt was higher in the LO, LC and CO groups than in the CC group. Thus, intrauterine protein restriction followed by overfeeding during lactation did not induce obesity, but produced glucose intolerance by impairing pancreatic function in adulthood.

Nutritional and Metabolic Profile in Nonalcoholic Fatty Liver Disease after Lifestyle Management

Aims: The aim of this study was investigate whether a comprehensive lifestyle management is able to promote improvements in the nutritional and metabolic profiles of obese women with NAFLD. Place and Duration of Study: This study was developed in the nutrition outpatient clinic of Julio Muller University Hospital from Mato Grosso Federal University at Cuiaba, Mato Grosso State, Original Research Article Feitoza et al.; JSRR, 5(6): 468-478, 2015; Article no.JSRR.2015.113 469 Brazil, during 6 months. Methodology: We assessed 61 obese women who received instructional treatment to change their lifestyle, at baseline and after 6 months, by anthropometric, biochemical, clinical and ultrasound measurements including liver steatosis, visceral and subcutaneous adiposity. Food intake was assessed by a qualitative food frequency questionnaire and the women were placed in NAFLD group or Control group based on the presence of liver steatosis. Results: No difference was found in food intake, but after treatment, both groups reduced their frequency of intake of fats, sugar and sweets and to increase their consumption of cereals, vegetables and fruits. The NAFLD group reduced body weight, waist circumference and liver steatosis. Both groups improved visceral and subcutaneous adiposity, the inflammatory cytokines (tumor necrosis factor-α, interleukin-6) whereas leptin were elevated and adiponectin were lowered during all the study. Strong positive correlations were found in the NAFLD group between visceral adiposity and body mass index, between subcutaneous adiposity and systolic and diastolic blood pressure, and between interleukin-6 and leptin. Although occurred in both groups during the study, high insulin resistance and low insulin sensitivity were more pronounced in the NAFLD group. Conclusion: We observed that even a small management in lifestyle can play an important role in the improvement of nutritional and metabolic profiles of obese women with NAFLD.

Effects of the Soybean Flour Diet on Insulin Secretion and Action

Publisher Summary Soybean is an important plant for human and animal nutrition due to its large amounts of protein, lipid, carbohydrates, minerals, vitamins, and fiber. Because of its reduced cost and elevated nutritional value, soybean flour has been used as alternative feed in the recovery of nutritional status. Part of the beneficial effects of soybean and by-products has been associated with their effects on insulin secretion and action. Insulin is an anabolic, polypeptide hormone synthesized by pancreatic β-cells, whose synthesis is activated by an increase of nutrients, especially glucose. Insulin acts on several periphery tissues, including liver, muscle, and adipose tissue. In rats, soybean flour diet activates the β-cell cAMP/PKA pathway, increasing insulin secretion in response to glucose, and decreases relative weight of fat deposits and even reduces the energetic expenditure without alterations in food intake. Soybean diet interferes in various steps of the insulin signaling pathway. Muscle insulin-reduced phosphorylation of GSK-3 is improved by soy proteins and isoflavones, partially preventing deleterious effects of fat feeding.

Nutritional recovery with rice bran did not modify energy balance and leptin and insulin levels

OBJECTIVE To investigate the effect of nutritional recovery with rice bran on energy balance, leptin and insulin levels. METHODS Weaned Wistar rats were fed on a 17% (Control - C) or 0.5% (Aproteic - A) protein diet for 12d. After this, rats were kept on a C diet (C) or recovered with control (Recovered Control - RC) or control plus recovered rice bran diet (Recovered Rice Bran - RRB). RESULTS Despite the increased food intake, group A exhibited lower carcass fat associated to low serum leptin. RRB and RC groups showed lower carcass weight and energy intake and expenditure. Energy expenditure was positively associated with food intake and carcass weight. Negative correlations between HOMA-IR and energy expenditure and energy intake were observed. CONCLUSION Nutritional recovery with rice bran did not modify energy balance, leptin and insulin levels.