The Effect Of Advanced Age On The Heterogeneity Of Nicotinic Acetylcholine Receptors Induced By Sepsis On Different Parts Of Skeletal Muscles

Object Elderly patients have dysfunctions in their skeletal muscles, especially of the leg and diaphragm muscles, the latter can be accompanied by sepsis. Changes in nicotinic acetylcholine receptor (nAChR) subunit composition may associate with these phenomena. No studies performed that show the alteration of nAChR subunit composition on adult and aged skeletal muscles with sepsis. We hypothesized that advanced age could up-regulate the expression of fetal nAChR (y-nAChR) and neuronal a7 nAChR (a7-nAChR) on tibialis anterior muscle and diaphragm muscle with sepsis.Methods Male adult (8 months, n=20) and aged (20 months, n=20) SD rats were randomly divided into sham and sepsis groups. Sepsis was induced by cecal ligation and puncture (CLP) operation. Blood, tibialis anterior and diaphragm muscle tissues were collected from each group at 24 h after CLP for various measurements.Results Up-regulation of γ-and a7-nAChR was found in CLP-Adult rats, CLP-Aged rats and SHAM-Aged rats (P< 0.05), but it was less robust in SHAM-Aged rats. The quantity of y-and a7-nAChR in CLP-Aged rats was much more than that in CLP-Adult rats (P< 0.05). Diaphragm muscle expressed more quantity of γ- and a7-nAChR than tibialis anterior muscle with sepsis (P< 0.05). Advanced age and sepsis up-regulated the expression of γ- and a7-nAChR separately.Conclusions Advanced age not only up-regulate the expression of y-and a7-nAChR, but also enhances the up-regulation of γ- and α7-nAChR induced by sepsis. Different parts of skeletal muscles expressed different quantities of γ-and a7-nAChR.