Impact of maternal protein restriction on muscle fiber and neuromuscular junction morphology of extensor digitorum longus muscle in 21-day-old rat offspring
International Journal of Development Research
Impact of maternal protein restriction on muscle fiber and neuromuscular junction morphology of extensor digitorum longus muscle in 21-day-old rat offspring
Received 18th March, 2018; Received in revised form 26th April, 2018; Accepted 14th May, 2018; Published online 30th June, 2018
Copyright © 2018, Leslie Cazetta Jeronimo et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
The fetal period is essential for the development of muscle fibers and neuromuscular junctions (NMJs). This study evaluated the effects of maternal protein restriction during pregnancy and lactation on muscle fibers and NMJs of extensor digitorum longus (EDL) muscle in 21-day-old rat offspring. Wistar rats were divided into a control group consisting of animals born to dams fed a normal protein diet (17% protein) during pregnancy and lactation, and a restricted group consisting of animals born to dams fed a low-protein diet (6% protein) during pregnancy and lactation. The pups were kept with their mothers throughout lactation (21 days). Samples of the EDL muscle were collected for the analysis of muscle fibers (hematoxylin-eosin and ultrastructure) and NMJs (nonspecific esterase) and for collagen quantification (Masson’s trichrome). Restricted animals exhibited an increase of 18% in the percentage of intramuscular collagen and a reduction of 43% in the cross-sectional area of the muscle spindle. In the restricted group, the area, major diameter and minor diameter of NMJs were reduced by 42%, 21% and 23%, respectively. Protein restriction during the period studied interfered with the formation and maturation of muscle and NMJs, affecting offspring growth and development.
