Our previous study demonstrated that
sepsis may decrease the activity of
acetylcholinesterase (AChE) at the neuromuscular junction (NMJ) of the diaphragm at 24 h, and thus improve the antagonistic action of
neostigmine on
rocuronium. The present study aimed to determine the effects of
sepsis on AChE activity over 2 weeks, which is a more clinically relevant time period. Furthermore, the present study aimed to elucidate the association between AChE activity and its expression at the NMJ during
sepsis. Male adult Sprague‑Dawley rats were randomly divided into the
sham or
sepsis groups.
Sepsis was induced by cecal
ligation and
puncture. On days 1, 3, 7 and 14 after surgery, AChE activity at the NMJ of the diaphragm was detected using a modified Karnovsky and Roots method. Furthermore, AChE expression levels at the NMJ, and in the whole muscle fibers of the diaphragm, were detected by immunohistofluorescence staining and western blot analysis, respectively. AChE activity was significantly decreased in the
sepsis group, with its lowest level detected on day 7; however, its activity had partially recovered on day 14 (P<0.01). AChE activity was positively correlated (r=0.975, P=0.025) with its expression at the NMJ, which showed a similar trend over 2 weeks of
sepsis. The
protein expression levels of AChE in the whole muscle fibers of the diaphragm were significantly decreased on days 1, 3 and 7 in the
sepsis group (P<0.01), with the lowest level observed on day 3. In conclusion,
sepsis decreased AChE activity by reducing its expression at the NMJ over 14 days; the reduced expression of AChE at the NMJ might be as a result of its reduced muscular production.