Maternal exposure to glyphosate-based herbicide promotes changes in the muscle structure of C57BL/6 mice offspring.

Glyphosate (GBH) is a worldwide consumption pesticide and is used in the formulation of Roundup®, one of the most commercialized herbicides in the world. Maternal exposure to this herbicide can promote changes and adaptations in the offspring; however, the effects on skeletal muscle are poorly understood. In this sense, the present study sought to evaluate the effect of exposure to GBH on the characteristics of the soleus (SOL) and extensor digitorum longus (EDL) muscles. C57BL/6 pregnant female mice were divided into two groups: control (CTL) receiving water and glyphosate (GBH; n = 6) receiving 0.5% glyphosate. Male puppies were designated according to the group to which the mothers belonged, such as CTL-F1 and GBH-F1 and then euthanized at 150 days of age. There was a reduction in body weight and nasoanal length of animals exposed to GBH, while there was an increase in EDL weight, reduction in the proportion of fibers and number of nuclei, and an increase in the connective tissue of the SOL. The animals exposed to GBH presented higher values of body characteristics, mainly adiposity gain, while they presented a reduction in neuromuscular junctions (NMJ), and an increase in fibrosis in the SOL muscle, while there was a reduction in the number of nuclei, and an increase in the weight of the EDL muscle. These findings indicate that glyphosate can promote changes in the offspring's body growth, the deposition of adipose panicles and its effects on muscle can lead to changes in the structure and functioning of this tissue.

Study of muscle fibers of the extensor digitorium longus and soleus muscles of C57BL/6 females exposed to glyphosate during pregnancy and lactation.

OBJECTIVE: To evaluate the morphology and morphometry of the muscles extensor digitorium longus and soleus of C57BL/6 females, who were exposed to glyphosate during pregnancy and lactation. METHODS: Twelve female mice from the C57BL/6 lineage were used. After detection of pregnancy, they were divided into a Control Group, which received only water, and a Glyphosate Group, which received water with 0.5% glyphosate during pregnancy and lactation. Both groups received ad libitum standard diet. After weaning, the females were euthanized and weighed; naso-anal length was measured, and fats were collected and weighed. The muscles extensor digitorium longus and soleus were collected, and their length and weight were measured. Then, the muscles were fixed in Methacarn to perform the histological study of muscle fibers. RESULTS: Glyphosate Group presented lower weight gain during pregnancy and also lower final body weight and naso-anal length; however, the other body parameters evaluated did not present a significant difference in relation to the Control Group. Significant differences were also not observed in the analysis of muscle fibers and connective tissue. CONCLUSION: Exposure to 0.5% glyphosate during pregnancy and lactation resulted in lower weight gain during pregnancy, final weight, and naso-anal length. Despite not directly altering the morphology of muscle tissue, these results may indicate enough exposure to interfere with animal metabolism.

Study of muscle fibers of the extensor digitorium longus and soleus muscles of C57BL/6 females exposed to glyphosate during pregnancy and lactation / Estudo das fibras musculares dos músculos extensor longo dos dedos e sóleo de fêmeas C57BL/6 expostas ao glifosato durante a prenhez e a lactação

ABSTRACT Objective To evaluate the morphology and morphometry of the muscles extensor digitorium longus and soleus of C57BL/6 females, who were exposed to glyphosate during pregnancy and lactation. Methods Twelve female mice from the C57BL/6 lineage were used. After detection of pregnancy, they were divided into a Control Group, which received only water, and a Glyphosate Group, which received water with 0.5% glyphosate during pregnancy and lactation. Both groups received ad libitum standard diet. After weaning, the females were euthanized and weighed; naso-anal length was measured, and fats were collected and weighed. The muscles extensor digitorium longus and soleus were collected, and their length and weight were measured. Then, the muscles were fixed in Methacarn to perform the histological study of muscle fibers. Results Glyphosate Group presented lower weight gain during pregnancy and also lower final body weight and naso-anal length; however, the other body parameters evaluated did not present a significant difference in relation to the Control Group. Significant differences were also not observed in the analysis of muscle fibers and connective tissue. Conclusion Exposure to 0.5% glyphosate during pregnancy and lactation resulted in lower weight gain during pregnancy, final weight, and naso-anal length. Despite not directly altering the morphology of muscle tissue, these results may indicate enough exposure to interfere with animal metabolism.

RESUMO Objetivo Avaliar a morfologia e a morfometria dos músculos extensor longo dos dedos e sóleo de fêmeas C57BL/6 expostas ao glifosato durante a prenhez e lactação. Métodos Foram utilizados 12 camundongos fêmeas da linhagem C57BL/6. Após detecção da prenhez, foram separadas em Grupo Controle, que recebeu somente água, e Grupo Glifosato, que recebeu água com 0,5% de glifosato durante a prenhez e lactação. Ambos os grupos receberam dieta padrão ad libitum. Após o desmame, as fêmeas foram eutanasiadas e pesadas; o comprimento nasoanal foi mensurado, e as gorduras foram coletadas e pesadas. Os músculos extensor longo dos dedos e sóleo foram coletados, e seu comprimento e peso foram mensurados. Em seguida, os músculos foram fixados em Methacarn para a realização do estudo histológico das fibras musculares. Resultados O Grupo Glifosato apresentou menor ganho de peso durante a prenhez e também menor peso corporal final e comprimento nasoanal, entretanto os demais parâmetros corporais avaliados não apresentaram diferença significativa em relação ao Grupo Controle. Na análise das fibras musculares e do tecido conjuntivo, também não foram observadas diferenças significativas. Conclusão A exposição a 0,5% de glifosato durante a prenhez e lactação resultou em menor ganho de peso na gestação, peso final e comprimento nasoanal, o que pode indicar que, apesar de não alterar a morfologia do tecido muscular diretamente, a exposição foi suficiente para interferir no metabolismo dos animais.