Cognitive restriction accentuates the increased energy intake response to a 10-month multidisciplinary weight loss program in adolescents with obesity.

BACKGROUND: Multidisciplinary interventions have shown some merits in weight reduction strategies in youth, however, their impact on subsequent daily energy intake remains largely unknown. The aim of the present study was to evaluate the nutritional responses to a 10-month multidisciplinary intervention among adolescents with obesity, in relation to their eating behavior characteristics. METHODS: Thirty-five adolescents (mean age: 13.4 ±â€¯1.2 years) with obesity took part in a 10-month residential multidisciplinary weight loss program. Anthropometric measurements, body composition (dual-energy X-ray absorptiometry), 24-h ad libitum energy intake (weighted), eating behaviors (Dutch Eating Behavior Questionnaire) and appetite sensations (Visual Analogue Scales) were assessed on three occasions: at their arrival in the institution (T0), after 5 months (T1), and at the end of the 10-month program (T2). RESULTS: The mean weight loss reached 11% of the adolescents' initial body weight, with an important inter-individual variability (-25% to +3% of their initial body weight). Results revealed sex differences change, with boys showing a higher decrease in fat mass percent and increase in fat-free mass compared with girls. Weight loss was accompanied by a significant decrease in emotional (-8.3%, p < 0.05) and external (-14.8%, p < 0.001) eating scores and a significant increase in 24-h ad libitum energy intake (+246 kcal, p < 0.001). The observed subsequent increased 24-h ad libitum energy intake at T2 compared to T0 was significantly higher in cognitively restrained eaters (+492 kcal) compared to unrestrained eaters (+115 kcal, p = 0,015). Dietary restraint score at baseline was inversely correlated with the percentage of weight loss (r = -0.44, p = 0.010). CONCLUSION: A 10-month multidisciplinary weight loss intervention induced an increase in 24-h ad libitum energy intake compared to baseline, especially in cognitively restrained eaters. Moreover, initially cognitively restrained eaters tended to lose less body weight compared to unrestrained ones. These findings suggest that cognitive restriction may be a useful eating behavior characteristic to consider as a screening tool for identifying adverse responders to weight loss interventions in youth.

Low vitamin D intake is associated with increase in cardiovascular risk factors in obese adolescents.

OBJECTIVES: This study aimed to investigate the effect of vitamin D on cardiovascular risk in obese adolescents. METHODS: Thirty (16 females/14 males) post-puberty obese adolescents (15-19 years) were involved and measurements of inflammatory biomarkers, body composition, visceral fat, and vitamin D (serum and intake) were performed. The adolescents were submitted to a long-term interdisciplinary therapy with physical exercise, nutritional, psychological, and clinical interventions. RESULTS: Negative correlations between vitamin D intake with plasminogen activator inhibitor-1 (PAI-1) (r=-0.69; p=0.01) and vascular cell adhesion molecule (VCAM-1) (r=-0.82; p=0.001) were found in the population analyzed. Improvement in PAI-1, VCAM-1, body composition, and visceral fat, were observed. CONCLUSIONS: We showed that low vitamin D intake is associated with an increase in the cardiovascular risk factors in obese adolescents.

Reduction in saturated fat intake improves cardiovascular risks in obese adolescents during interdisciplinary therapy.

BACKGROUND/OBJECTIVES: Obesity is related to inflammation and cardiovascular disease. The increase in saturated fatty acid intake (SFA) can potentiate cardiovascular risks. The aim of this study was to assess the influence of change in SFA on carotid intima-media thickness (cIMT), metabolic profile and anti/pro-inflammatory adipokines in obese adolescents. METHODS: Sixty obese adolescents were subjected to 1 year of interdisciplinary intervention (nutrition, psychology, physical exercise and clinical therapy). Blood glucose, insulin, lipid profile, leptin and adiponectin were analysed. Insulin resistance was estimated by HOMA-IR and HOMA-AD. cIMT was measured by ultrasonography. Dietetic intake was calculated by 3-day dietary record. Volunteers were analysed according to tertiles of change (Δ) in SFA intake: Low-SFA reduction<3.68 g; Moderate-SFA reduction 3.68-13.67 g; and High-SFA reduction>13.67 g. RESULTS: Moderate and High-SFA tertiles presented reduction in insulin, leptin/adiponectin ratio, cIMT and increase in adiponectin and adiponectin/leptin ratio. Adiponectin/leptin ratio was predictor of cIMT. HOMA-IR, total cholesterol and LDL-cholesterol reduced only in High-SFA tertile, and was associated with SFA independent of visceral fat. Negative correlations between Δ of SFA and adiponectin and adiponectin/leptin ratio were observed. CONCLUSION: Obese adolescents with moderate and high reduction in SFA presented improvements on pro/anti-inflammatory biomarkers and cIMT, leading to reduction in cardiovascular risks.

Saturated fatty acid intake can influence increase in plasminogen activator inhibitor-1 in obese adolescents.

The aim of this study was to verify if saturated fatty acid intake adjusted by tertiles can influence metabolic, inflammation, and plasminogen activator inhibitor-1 (PAI-1) in obese adolescents. Body mass, height, body mass index, waist circumference, blood pressure, and body composition of 108 obese adolescents were obtained. Fasting glucose, insulin, PAI-1, and CRP were determined. Insulin resistance was assessed by Homeostasis Model Assessment (HOMA-IR) and insulin sensitivity by Quantitative Insulin Sensitivity Check Index (QUICKI). Dietetic intake was estimated by a 3-day dietary record, and volunteers were divided according to consumption of saturated fatty acids: tertile 1 [Low Saturated Fatty Acid Intake (Low-SFA): ≤12.14 g], tertile 2 [Moderate Saturated Fatty Intake (Moderate SFA intake): 12.15-20.48 g], and tertile 3 [High Saturated Fatty Acid Intake (High-SFA Intake); >20.48 g]. Statistical analysis was performed using STATISTICA 7.0 software and the significance level was set at p<0.05. The most important finding in the present study is that Moderate and High-SFA intakes presented significantly higher values of PAI-1 than Low-SFA Intake. PAI-1 was positively associated with saturated fatty intake, waist circumference, mean blood pressure, and HOMA-IR. SFA intake was predictor of PAI-1 independent of body fat, HOMA-IR and total-cholesterol. In addition, PAI-1 was an independent predictor of blood pressure. HOMA-IR and QUICKI presented significantly higher and lower, respectively, in High-SFA compared to Moderate-SFA intake. High-SFA influenced cardiovascular disease risks, since it increased PAI-1 and insulin resistance, and decreased insulin sensibility, leading to vicious cycle among food ingestion, pro-thrombotic state, and cardiovascular risks in obese adolescents.

Effects of different physical exercises on leptin concentration in obese adolescents.

In order to compare the effects of leisure physical activity (LPA), aerobic training (AT) and aerobic plus resistance training (AT + RT) as part of a 6-month interdisciplinary therapy in body composition, insulin resistance and leptin concentrations in obese adolescents, 72 volunteers (n = 24 in each group) ages 15-19 years were evaluated. Delta (Δ) body mass (kg) and Δ BMI (kg/m(2)) was different between AT and LPA groups and in AT + RT group compared to both LPA and AT groups; Δ body fat mass (kg and %) was different only in AT + RT group compared to both LPA and AT; Δ body lean mass (%) was different only in AT + RT group; Δ body lean mass (kg) was negative only in AT and positive and different from AT in AT + RT group; ΔHOMA-IR did not differ among groups; Δ leptin (ng/ml) was negative and different from LPA for both AT and AT + RT groups. In conclusion, both AT and AT + RT promoted a reduction on leptin levels, however, the adolescents subjected to AT + RT presented better results in body composition than the AT group. These results highlight the importance of associating aerobic and resistance training with nutritional and psychological approaches in the treatment of obese adolescents.

The role of leptinemia state as a mediator of inflammation in obese adults.

Hyperleptinemia has emerged as a marker of proinflammatory status, while the adiponectin/leptin ratio has been used to identify anti-inflammatory state. In this context, the aims of the present study were to investigate the role of leptinemia, adjusted by tertiles, on inflammatory state in obese adults according to obesity degree. This is a cross-sectional study comprised of 43 obese adults. The anthropometric variables and body composition were analyzed, as well as markers of inflammation such as leptin, adiponectin, and plasminogen activator inhibitor. Subjects were grouped using adjusted tertiles of the leptin levels. The major finding was the negative correlation between leptin concentration with adiponectin/leptin ratio (r=-0.622, p=0.000) and the positive correlation with leptin/adiponectin ratio (r=0.622, p=0.000). Indeed, both ratios were decreased and increased, respectively, according to the obesity degree. Furthermore, in the stepwise multiple linear regression analysis, the high degree of obesity was an independent predictor of leptinemia when adjusted for age and BMI (ß=0.588, p=0.000 and ß=0.778, p=0.005). Finally, the strong negatively correlation between the leptinemia with adiponectin/leptin ratio and the positive correlation with leptin/adiponectin ratio reinforce the role of this adipokine as a biomarker of inflammation in obese adults, according to obesity degree. Our findings can elucidate that hyperleptinemic status was a major factor in the proinflammatory status related to higher obesity degree. All together, these data reinforce the role of leptinemia state as a mediator of inflammation in obese adults.

Is the neck circumference an emergent predictor for inflammatory status in obese adults?

BACKGROUND: Plasminogen Activator Inhibitor 1 (PAI-1) is a prothrombotic adipokine involved in the coagulation cascade and fibrinolysis that associated with proinflammatory adipokines may increase the risk related to obesity. Anthropometric measures are commonly used in clinical practice and, currently, neck circumference (NC) has been used as a marker of cardiovascular risk that can favour inflammatory factors. OBJECTIVE: To verify the possible correlations between prothrombotic and pro/anti-inflammatory markers with anthropometric measurements in obese. SUBJECTS AND METHODS: A total of 43 obese adults were enrolled. The variables include body mass, stature, body mass index (BMI), NC, chest circumference (CC), abdominal circumference (AC), hip circumference (HC), blood pressure and blood collection used to assess the level of adipokines. RESULTS: The sample was stratified by BMI. PAI-1 levels were positively correlated with body mass (r=0.31, p=0.04), NC (r=0.43, p=0.004), CC (r=0.40, p=0.004), AC (r=0.37, p=0.01), diastolic blood pressure (r=0.35, p=0.03), leptin/adiponectin ratio (r=0.36, p=0.01) and negatively correlated with adiponectin (r=-0.34, p=0.02). In stepwise multiple linear regression analysis, NC showed to be an independent predictor to PAI-1 when adjusted for gender and BMI, according to the age (ß=0.47, p=0.02 and ß=0.42, p=0.02 respectively). CONCLUSION: In conclusion, NC could be suggested as an independent predictor higher PAI-1. This association can be a new screening of persons at an enhanced cardiovascular risk and inflammation in this obese population, so useful in clinical practice.

Chronic exercise promotes alterations in the neuroendocrine profile of elderly people.

Aging and physical inactivity are 2 factors that favour the development of cardiovascular disease, metabolic syndrome, obesity, and diabetes. In contrast, adopting a habitual moderate exercise routine may be a nonpharmacological treatment alternative for neuroendocrine aging disorders. We aimed to assess the effects of moderate exercise training on the metabolic profiles of elderly people with sedentary lifestyles. Fourteen sedentary, healthy, elderly male volunteers participated in a moderate training regimen for 60 min/day, 3 days/week for 24 weeks at a work rate equivalent to their ventilatory aerobic threshold. The environment was maintained at a temperature of 23±2°C, with a humidity of 60±5%. Blood samples for analysis were collected at 3 intervals: at baseline (1 week before training began), and 3 and 6 months after training. The training promoted increased aerobic capacity (relative VO(2), and time and velocity to VO(2)max; (p<0.05)) and reduced serum α-MSH (p<0.05) after 3 months of training when compared with the baseline data. In addition, serum thyroid hormone (T3 and T4) was reduced after 6 months of training compared with baseline levels. Our results demonstrate that a moderate exercise training protocol improves the metabolic profile of older people, and metabolic adaptation is dependent on time.

The role of orexigenic and anorexigenic factors in an interdisciplinary weight loss therapy for obese adolescents with symptoms of eating disorders.

AIM: The aim of this study was to evaluate the role of orexigenic and anorexigenic factors in an interdisciplinary weight loss therapy for obese adolescents with symptoms of eating disorders. METHODS: Thirty-seven post-pubertal, obese adolescents (14 to 19 years old) with symptoms of eating disorders were submitted to long-term interdisciplinary therapy (1 year). Bulimic and binge eating symptoms were measured using the Bulimic Investigatory Test, Edinburgh, and the Binge Eating Scale respectively. Neuropeptide Y, melanin-concentrating hormone, total ghrelin, alpha-melanocyte stimulating hormone and leptin were measured using radioimmunoassay. RESULTS: After long-term interdisciplinary therapy, the adolescents showed significantly improved body composition, visceral and subcutaneous fat and reduced symptoms of bulimia and binge eating. Intriguingly, orexigenic peptides were up-regulated after short-term therapy and down-regulated at the end of therapy, whereas the anorexigenic pathway was improved with therapy. Furthermore, after long-term therapy, a negative correlation was observed between leptin concentration and melanin-concentrating hormone. DISCUSSION: We suggest that long-term therapy promotes an intrinsic association between weight loss, improvement of eating disorder symptoms and a decrease in orexigenic factors. Together, these results represent a more effective course by which patients can normalise behaviours related to eating disorders as well the actions of hormones involved in energy balance, and thus advance obesity control. CONCLUSION: Long-term interdisciplinary therapy was effective to improve anorexigenic and orexigenic factors that influence energy balance and avoid the development of eating disorders in obese adolescents. However, the associations between eating disorders and neuroendocrine factors need to be confirmed in future studies.

The effect of the aerobic training on morphological and histochemical characteristics of tibial anterior muscle in rats fed with high fat diet

The aim of this study was to investigate the effect of high fat diet and different frequencies of swimming programs in the tibial anterior muscle in male Wistar rats. In conclusion, the aerobic training during two days/week and five days/week caused injuries in muscle fibers and the high fat diet did not cause statically significant results compared to normal diet.

El objetivo de este estudio fue investigar el efecto de dietas ricas en grasas y diferentes frecuencias de natación, en el músculo tibial anterior, de ratas machos Wistar. El entrenamiento aeróbico, durante dos y cinco días por semana, causó lesiones en las fibras musculares y la dieta alta en grasa, no produjo resultados estadísticamente significativos, en comparación con la dieta normal.

Prevalence and risk factors of metabolic syndrome in Brazilian and Italian obese adolescents: a comparison study.

BACKGROUND: Metabolic syndrome (MS) prevalence between different populations in obese adolescents is scanty to date. OBJECTIVE: To compare the MS prevalence and related risk factors in Brazilian and Italian obese adolescents. METHODS: A total of 509 adolescents (110 Brazilian, 399 Italian), aged 15-19 years. Anthropometric characteristics, triglycerides (TG), total, low-density lipoprotein (LDL)-, high-density lipoprotein (HDL)-cholesterol, fasting plasma glucose (FPG), insulin, homeostasis model assessment of insulin resistance (HOMA-IR) and blood pressure were measured. RESULTS: Age, body mass index (BMI) and BMI z-score were not significantly different between the two subgroups. BMI z-score, TG, FPG, HOMA-IR and systolic blood pressure (SBP) were significantly higher in boys than in girls both in Brazilian and Italian adolescents, while HDL-cholesterol levels were lower in boys than in girls. No significant differences were observed in BMI, LDL and total-cholesterol and DBP in two genders and groups. Insulin, FPG, HOMA-IR and TG were significantly higher, while LDL-cholesterol and SBP were significantly lower in Brazilian than in Italian subjects, both in males and females. HDL and total-cholesterol and diastolic blood pressure (DBP) were not significantly different between the two subgroups and genders. MS prevalence was higher in Brazilian than in Italian obese boys (34.8 vs. 23.6%, p < 0.001) and girls (15.6 vs. 12.5%, p < 0.01). The most frequently altered parameter was HOMA-IR both in subjects with MS (100% in Brazilian and 81.8% in Italian) and without MS (42.9% and 11.7%). CONCLUSION: Metabolic syndrome represents a worldwide emerging health problem in different ethnical populations, the alterations of the risk factors related to MS (different in their prevalence between different subgroups) being strictly linked to the degree of obesity.

Relationship between nonalcoholic fatty liver disease prevalence and visceral fat in obese adolescents.

BACKGROUND: Visceral adiposity is the major risk factor for paediatric nonalcoholic fatty liver disease. AIMS: Determine the prevalence of nonalcoholic fatty liver disease according to the visceral fat quartile. SUBJECTS: 181 obese adolescents including 113 girls (16.58+/-1.56 years) and 68 boys (16.87+/-1.62 years) were evaluated. METHODS: The inclusion criteria were obesity and post-pubertal stage of Tanner. Visceral fat of obese adolescents was distributed in quartiles after ultrasound nonalcoholic fatty liver disease diagnosis. RESULTS: Nonalcoholic fatty liver disease prevalence was 45.30%. It was observed that 62.07% and 76.47% of girls and boys with nonalcoholic fatty liver disease were found in the 4th quartile. In a multivariate logistic analysis it was observed that only visceral fat remained statistically significant, every 1cm increase in visceral fat was associated with a 1.97 fold (95% CI 1.06-3.66) in boys and 2.08 fold (95% CI 1.38-3.13) in girls increased risk to develop nonalcoholic fatty liver disease. Indeed it was verified a positive correlation between visceral fat, body mass index, insulin levels, homeostasis model assessment insulin resistance index and steatosis degree. CONCLUSIONS: Our findings suggested that the expansion of visceral fat was a determinant factor to increase nonalcoholic fatty liver disease prevalence and the visceral fat measured by ultrasound might be a good predictor to identify risk for nonalcoholic fatty liver disease in obese adolescents. It was confirmed by a stronger correlation between visceral fat and body mass index.

O exercicio de final de semana contribui para o controle das dislipidemias em ratos adultos machos alimentados com dieta rica em gorduras / The weekend exercise contribute to the control in the hiperlipidaemias in adults male rates feeding with lipids diet

Sabe-se que o sedentarismo, associado a uma dieta nao balanceada tem grande importancia para o desenvolvimento de doencas cronico degenerativas. Por outro lado, o exercicio fisico tem sido um meio utilizado para o controle dessas doencas. Entretanto, pouco foi relatado sobre efeitos do exercicio de final de semana nocontrole das dislipidemias. Assim, o objetivo deste estudo foi observar respostas adaptativas ao exercicio de final de semana sobre o metabolismo das lipoproteinas em ratos machos alimentados com dieta hiperlipidica. Foram divididos em grupos 96 ratos machos adultos: dieta normocalorica (N) e hipercalorica (H), sedentario (S), treinado continuo (TC) e treinado de fim de semana (TFS), 5 e 2 sessoes semanais/90minutos/dia, respectivamente, por natacao. Durante todo o periodo experimental foram controlados: o peso e o consumo alimentar em gramas. Foram coletados, pesados e congelados o plasma (P), os tecidos adiposos barncos retropeitoneal (RET) e epididimal (EPI), tecido adiposo marron (TAM), musculo gastrocnemio (GAST), figado (FIG) e coracao (COR), para posteriores analises. Foram considerados significativos os valores de p<-0,05 a partir da analise de variancia `Anova Tree Way`. O treinamento de final de semana promoveu diminuicao significativa nos triglicerideos plasmaticos em animais hipercaloricos (SH 180,7+-13,9 vs TFSH97,2+-8,3). Os dois tipos de treinamento foram importantes no controle das dislipidemias em ratos alimentados com dieta hipercalorica, sendo observado aumento na concentracao de HDL colesterol em relacao aos respectivos animais sedentarios (SH 26,5+-2,0 vs TCH 35,7+-6,2 e TFSH 37,1+-1,2)

Efeitos do exercicio cronico com orientacao nutricional sobre parametros lipidicos de mulheres obesas / Effect of chronic exercise with nutritional orientation on lipidics variables at plasm from obese women

A obesidade e uma doenca com incidencia epidemiologica atinge 41,5 (por cento)da populacao brasileira e esta fortemente relacionada as dislipidemias. O objetivo do presente estudo foi observar os efeitos do exercicio cronico de intensidade moderada, realizado 2 vezes por semana durante um periodo de 12 semanas, acompanhado de orientacao nutricional, sobre a composicao lipidica no plasma de mulheres obesas. Para este estudo foram considerados os seguintes parametros: avaliacao antropometrica (peso, estatura e circunferencias da cintura e do quadril), concentracao de glicose e lipidios no soro (lipidios totais triglicerides e colesterol total, pelo metodo colorimetrico enzimatico) e avaliacao clinica nutricional. Decorrente do exercicio e da orientacao nutricional observou-se diminuicao significativa de 29,8(por cento) na concentracao de lipidios totais e de 9,50(por cento) no colesterol total (*p< 0,05), reducao media de 9,9(por cento) na concentracao de glicose sanguinea e de 18,9(por cento) na concentracao de triglicerides. Desse modo, acreditamos que este modelo de intervencao (exercicio moderado associado a orientacao nutricional) contribui de forma substancial para o controle da obesidade e alteracoes no metabolismo lipidico

Ethanol intake during lactation. I. Effects On dams' metabolism and pups' body weight gain.

Wistar lactating rats (8 pups per dam) had free access to either tap water (control group, C) or one of three concentrations of ethanol (E) in the drinking water: 5% (E5), 10% (E10), and 20% (E20). All animals received normal rat chow ad libitum and were killed on day 12 of lactation. Intake of both 10% and 20% ethanol solutions decreased food intake, dams' body weight, and pups' body weight gain as compared with findings in the C group. The relative weights (g/100g b.w.) of the mammary glands (MG) and of the parametrial white adipose tissue depot were decreased only in E20 as compared with findings in the C group. Protein and lipid content of these tissues were not altered in any of the ethanol groups. In comparison with the C group, the lipogenesis rate was increased in the MG (135. 6%) and liver (120.2%) in E5 and the MG (58.1%) and parametrial white adipose tissue depot (147.0%) in E20. No modifications in lipogenesis rate were noted in E10. The malic enzyme activity was decreased in the MG in E10 (25.3%) and E20 (26.4%) and in the liver in E20 (45.7%). In E5, however, it was increased in the liver (23. 9%). The activity of ATP-citrate lyase in the liver was decreased in E20 (56.7%), while it was increased by 37.5% in E5 and 34.2% in E10. Blood glucose concentration of dams was not affected by ethanol ingestion. However, plasma triacylglycerol concentration was higher in E10 (17.9%) and E20 (13.3%) than in the C group, and plasma protein was lower in E20 (15.7%) than in C. We concluded that alcohol intake during lactation increased the MG lipogenesis rate; although at the highest dose, this metabolic alteration was not enough to allow normal pups' growth. However, the low dose of ethanol (5%), despite having altered dams' metabolism, did not affect pups' body weight gain.

Ethanol intake during lactation. II. Effects On pups' liver and brain metabolism.

Lactating rats, with litters adjusted to 8 pups on day 1, were divided into 4 groups: control animals (C), which received water and Nuvilab chow ad libitum, and ethanol animals (E), which received 20% (E20), 10% (E10), or 5% (E5) ethanol diluted in the drinking water and Nuvilab chow ad libitum. On day 12 of life, the pups were weighed and decapitated. The intake of 10% and 20% ethanol solutions by the lactating rats decreased the pups' body weight and liver weight. The pups' liver ATP-citrate lyase activity was decreased in all ethanol groups. The pups' brain weight decreased in E20 only. Glucose metabolism and lactate production were studied in the pups' brain slices, which were incubated at 37 degrees C in Krebs-Henseleit buffer under carbogen in the presence of glucose (5 mM) plus 14C-glucose (0.04 microCi) with or without beta-hydroxybutyrate or insulin. Study of the incubated pups' brain slices showed that the intake of the 20% ethanol solution by the dams increased glucose consumption, oxidation, lactate production, and lipogenesis rate from glucose in all media studied, as compared with findings in the C group. In the pups' brain slices, the lactate production and lipogenesis rate from glucose were higher in E10 than in the C group. The addition of beta-hydroxybutyrate to the incubation medium caused a decrease in glucose oxidation in C, E5, and E20 and an increase in glucose consumption in E10. Ingestion of the 5% ethanol solution by dams decreased the pups' brain lipogenesis rate from glucose in all media studied. We concluded that the effects of maternal alcohol intake on the pups' development and metabolism are dose-dependent. High amounts of ethanol intake (10% or 20%) caused a great impairment in the pups' growth, as well as their liver and brain metabolism. The low dose (5%) did not affect the pups' body weight gain or their brain and liver weight, but it did alter brain glucose metabolism.

Effect of adrenalectomy and glucocorticoid therapy on lipid metabolism of lactating rats.

Although adrenal glucocorticoids were known to be important for adequate milk production, little is known about their effects on the metabolism of mammary glands during lactation. In this study, lactating Wistar rats on the 12th day of lactation were divided in the following groups: sham-operated (SO) and adrenalectomized (ADX) receiving no treatment; SO and ADX starved for 24 h and refed intragastrically with 2.5 ml of 50% glucose solution, 2 h before the experiment (SOR and ADXR) and ADX receiving substitute therapy with dexamethasone (ADX + DEX). Sacrifices were performed 2 days after surgery. Weight, lipid content and in vivo lipogenesis rate were evaluated in mammary gland (M.GLAND), liver, parametrial white adipose tissue (PARA) and interescapular brown adipose tissue (BAT). ATP citrate lyase activity was measured in M.GLAND, liver and PARA of SO, ADX and ADX + DEX. The rate of lipogenesis and 14CO2 production from 14C-glucose by isolated acini from M.GLAND and plasma glucose were also determined. In ADX rats, food intake, lipid content, in vivo lipogenesis rate and ATP citrate lyase activity in M.GLAND were significantly lower than those in SO rats. The M.GLAND lipogenesis rate of SOR group was similar to the value found in SO rats. In ADXR rats, the M.GLAND lipogenesis rate was not normalized. However, the therapy with DEX elevated lipid content, in vivo lipogenesis rate and ATP citrate lyase activity to levels similar to those in SO. These results suggest that the glucocorticoids are essential for the occurrence of normal lipid synthesis in M.GLAND during lactation.