Programação metabólica por exposição materna ao glifosato: avaliação morfológica dos músculos extensor longo dos dedos e sóleo de camundongos C57BL/6

Abstract

Maternal exposure to several xenobiotic compounds, such as glyphosate, can promote morphological alterations and adaptations in the fetus, with effect on longterm health. Glyphosate is a pesticide used worldwide, being associated with the occurrence of several diseases, however the effects on skeletal muscles are not yet know. This study aimed to evaluate the morphology and morphometry of muscle fibers of the extensor digitorium longus (EDL) and soleus (SOL) muscles of dams exposed to glyphosate during pregnancy and lactation and evaluate the morphology and morphometry of muscles fibers of the EDL and SOL muscles and the neuromuscular junctions (NMJs) of their offspring. Twelve pregnant female mice of the C57BL/6 strain were separated into a control group (CTL), which received water and glyphosate group (GF), which received water with 0.5% of glyphosate during pregnancy and lactation. After weaning, the offspring of males was separated into two groups: CTL-F1 (n=10), puppies of the CTL mothers and GF-F1(n=10), puppies of GF mothers. Then, the females were euthanized, weighed, measured the nasoanal length (NAL) and the fats were collected and weighed. The ELD and SOL muscles were collected, weighed (g) and measured the length (mm) of both. The same procedures were performed in the euthanasia of the offspring, when they completed 150 days of life. The right antimere of the mother's and offspring's muscles were fixed in metacarn for the histological study of muscle fibers. The left antimere of the EDL and SOL muscles of the offspring were fixed in Karnovsky for the histochemical study of JNMs. GF mothers presented lower body weight gain (p=0.0327) during pregnancy, lower weight (0.0103) and NAL (p=0.0002) when compared to CTL. Regarding offspring, gf-F1 animals showed lower weight (p=0.0153) and NAL (p=0.0463) when compared to CTL-F1. The EDL muscle of the GF-F1 group showed a lower number of central nuclei (p=0.0409) when compared to CTL-F1, also observed SOL muscle although not significant. Regarding connective tissue, increased amount of tissue was observed in the SOL muscle (p=0.0419) of the GF-F1 group when compared to CTL-F1. The results found in mothers and offspring indicated that exposure to glyphosate during the pregnancy and lactation period was sufficient to alter the metabolism of mothers, who gained less weight during pregnancy and were lower weight and NAL. Besides being able to alter the development of offspring, which also had smaller body size and a smaller number of central nuclei in the fibers of the ELD and greater amount of connective tissue in the SOL, which may culminate in changes in tissue regeneration.