RESUMO: A semente de linhaça é considerada um alimento funcional com vários efeitos benéficos à saúde. Entretanto, devido ao seu elevado teor de fitoestrógenos, esta semente pode influenciar no metabolismo hormonal e interferir na biomorfologia gonadal. Neste estudo, utilizamos a histomorfometria computadorizada para avaliar os túbulos seminíferos e epididimários, considerando as diferentes regiões do epidídimo (cabeça, corpo e cauda) de ratos submetidos a uma dieta prolongada de semente de linhaça. Foram utilizados ratos Wistar machos adultos jovens (n=20) divididos em 2 grupos, durante o período de lactação: Grupo Controle (GC) a base de caseína e Grupo Linhaça (GL) alimentados com 25% de semente de linhaça. Ao final de 250 dias de ingestão contínua, os animais foram sacrificados e amostra de sangue foi coletada. Os testículos e epidídimos foram retirados e fixados em formol tamponado. As amostras foram submetidas ao processamento histológico de rotina para parafina e coradas em hematoxilina e eosina. Foi feita a imunomarcação com anticorpo antivimentina para identificação das células de Sertoli. Para morfometria, as imagens das lâminas foram digitalizadas e analisadas pelo software ImageJ para obtenção dos dados de altura epitelial, diâmetro e área tubular e luminal. Na avaliação hormonal o GL teve maior concentração de estrógeno sérico (p=0,001), mas nenhuma mudança na concentração de testosterona foi observada. Nos parâmetros morfométricos dos túbulos seminíferos e das regiões epididimárias, não houve diferenças significativas entre os grupos analisados. Da mesma forma, a quantificação das células de Sertoli não apresentaram diferenças significativas no GL (p=0,98). Estes resultados mostraram que o consumo contínuo e prolongado de 25% de semente de linhaça desde período gestacional até 250 dias de idade, mesmo com o aumento significativo nos níveis séricos de estradiol, não exerceram efeitos adversos sobre a estrutura testicular e epididimária, assim como nas células participantes da espermatogênese em ratos.

ABSTRACT: Flaxseed is considered a functional food with several health benefits. However, because of its high phytoestrogen content, flaxseed influences hormone metabolism and affects the gonadal biomorphology. In this study, computerized histomorphometry was used to evaluate seminiferous and epididymal tubules, considering the different regions of the epididymis (head, body and tail) of rats subjected to a prolonged diet of flaxseed. Young adult male Wistar rats (n=20) were divided into 2 groups during their lactation period: Control Group (CG), fed casein-based meals and Flaxseed Group (FG), fed a 25% flaxseed meal. After 250 days of continuous ingestion, the animals were euthanized and a blood sample was collected. The testicles and epididymis were removed and fixed in buffered formalin solution. The samples were subjected to routine histological paraffin techniques and stained with hematoxilin and eosin. Immunostaining was performed using an antivimentin antibody for Sertoli cell identification. For morphometry, images of the slides were scanned and analyzed using Image J to determine the epithelial height, tubular and luminal diameter and tubular and luminal area. In the hormonal evaluation, FG had a higher serum concentration of estrogen (P=0.001), but no change was observed in the concentration of testosterone. The morphometric assay of seminiferous tubules and epididymal regions revealed no significant differences between the analyzed groups. Similarly, Sertoli cell quantification showed no significant differences in the FG (P=0.98). These results revealed that the continuous and prolonged intake of 25% flaxseed meals from gestation to 250 days of age, even with a significant increase in serum levels of estradiol, does not exert adverse effects on the testicular and epididymal structure or on the cells participating in the spermatogenesis of rats.

OBJETIVO: Avaliar os efeitos do consumo da semente de linhaça durante a lactação sobre o peso corporal, indicadores hematológicos e massa de gordura visceral dos filhotes de ratas na idade adulta. MÉTODOS: Foram utilizadas 16 ratas Wistar que, após o parto, foram divididas em dois grupos que receberam, durante a lactação, as seguintes dietas: grupo-controle (GC), ração à base de caseína, e grupo linhaça (GL), ração à base de caseína contendo 25% de semente de linhaça. Ao desmame, os filhotes machos passaram a receber ração comercial até a idade adulta, quando foram sacrificados aos 170 dias de vida para coleta de sangue e avaliação da massa de gordura visceral. RESULTADOS: Foi encontrado menor peso corporal da prole do GL (GL = 42,69±3,06 g; GC = 47,31±4,72 g; p = 0,036) ao desmame. Aos 170 dias de idade foram observados menores valores na hemoglobina do GL (GL = 12,30±1,28 g/dL; GC = 13,88±0,91 g/dL; p = 0,02). Não foram verificadas diferenças estatísticas na massa de gordura visceral entre os grupos. CONCLUSÕES: O consumo materno da ração à base de semente de linhaça durante a lactação promoveu menor peso ao desmame e níveis menores de hemoglobina na idade adulta quando comparados ao GC.

OBJECTIVE: To investigate the effects of maternal flaxseed consumption during lactation on the body weight, hematological indicators and visceral fat mass of male offspring in adulthood. METHODS: Sixteen female Wistar rats were divided into two groups after giving birth. During lactation the control group (CG) was fed a casein-based diet and the flaxseed group (FG) was fed a casein-based diet containing 25% flaxseed. After weaning, male offspring were fed on commercial chow until adulthood and euthanized at 170 days for blood collection and visceral fat mass assessment. RESULTS: Offspring of rats in the FG had lower body weight (FG = 42.69±3.06 g; CG = 47.31±4.72 g; p = 0.036) at weaning. At 170 days, lower hemoglobin levels were observed in the FG (FG = 12.30±1.28 g/dL; CG = 13.88±0.91 g/dL; p = 0.02). There was no statistically significant difference in visceral fat mass between groups. CONCLUSIONS: Maternal consumption of a flaxseed-based diet during lactation resulted in lower body weight at weaning and lower hemoglobin levels in adulthood, when compared with the control group.

The aim of the present study was to evaluate the chronic toxicity of ethanol low blood levels in malnourished rats. Female Wistar rats (220 g) were subjected to either an ad libitum diet (W, well-nourished, n=10) or food restriction (M, malnourished, n=10). Water (WW and MW) or ethanol solution (W5% and M5%) was offered to half of each nutritional group (n=5) as the only fluid source. The treatment was continued for two months. After sacrifice, blood biochemical parameters and macroscopic, histologic and morphometric evaluation of the liver were performed. Results indicated that: Ethanol consumption was higher in malnourished rats and minimized body weight loss in malnourished rats, while it decreased the body weight gain in well-nourished ones. Behavioral ethanol intoxication was more severe in malnourished rats. Malnutrition decreased hematocrit and hemoglobin but, on the other hand, ethanol was a protective factor of that effect (hemoglobin: MW 10.6 mg/dl / ME 13.02 mg/dl, p< 0.05). Ethanol increased the relative liver weight of both well-nourished and malnourished rats. Ethanol intake minimized iron pigment, collagen area and binuclear hepatocyte/ field increased by malnutrition. These data are in accordance with previous reports which showed ethanol as an important source of calories and, even chronically, ethanol still attenuates the effects of malnutrition.