ABSTRACT
OBJECTIVE@#To explore the effect of subchronic combined oral exposure of titanium dioxide nanoparticles and glucose on levels of serum folate and vitamin B12 in young SD rats.@*METHODS@#At first, the physical and chemical properties of titanium dioxide nanoparticles, such as particle size, shape, crystal form and agglomeration degree in solution system, were characterized in detail. Eighty 4-week-old young SD rats were randomly divided into 8 groups (10 rats in each group, half male and half female). The rats were exposed to titanium dioxide nanoparticles through intragastric administration at 0, 2, 10 and 50 mg/kg body weight with or without 1.8 g/kg glucose daily for 90 days. At last, the concentrations of serum folate and vitamin B12 were detected.@*RESULTS@#Titanium dioxide nanoparticles were anatase crystals, closely spherical shape, with an average particle size of (24±5) nm. In male young rats, compared with the control group, the serum folate concentration was significantly increased when exposed to titanium dioxide nanoparticles (10 mg/kg) and glucose. The difference was statistically significant (P<0.05). However, in female and male young rats, compared with glucose (1.8 g/kg) exposure group, titanium dioxide nanoparticles (50 mg/kg) and glucose significantly reduced the serum folate concentration. The difference was statistically significant (P<0.05). Through statistical analysis of factorial design and calculation of interaction, obvious antagonistic effect was observed between titanium dioxide nanoparticles and glucose on the serum folate concentration in the young female SD rats. The combined oral exposure of titanium dioxide nanoparticles and glucose had little effect on the concentration of serum vitamin B12 in the young SD rats, with no significant interaction between the two substances. It was only found that titanium dioxide nanoparticles (2 mg/kg) and glucose significantly increased the serum vitamin B12 concentration, compared with glucose (1.8 g/kg) exposure group. The difference was statistically significant (P<0.05).@*CONCLUSION@#Subchronic combined oral exposure of titanium dioxide nanoparticles and glucose had an obvious antagonistic effect on serum folate concentrations in young SD rats.
Subject(s)
Animals , Female , Male , Rats , Folic Acid , Glucose , Metal Nanoparticles , Rats, Sprague-Dawley , Titanium , Vitamin B 12 , VitaminsABSTRACT
<p><b>BACKGROUND</b>Mast cells are implicated in the development of irritable bowel syndrome (IBS), which is associated with the activation of the "neural-immune" system. The aim of this study was to investigate the role of mast cells in the remodeling of cholinergic and peptidergic neurotransmitters induced by acute cold restriction stress (ACRS) post infection (PI) using mast cell deficient rats (Ws/Ws) and their wild-type controls (+/+).</p><p><b>METHODS</b>Transient intestinal infection was initiated by giving 1500 Trichinella spiralis (T.S.) larvae by gavage. ACRS was induced for 2 hours at day 100 PI. Samples of terminal ilea were prepared for H&E staining, mast cell counting and activation and assessment of IL-1beta and IL-10.</p><p><b>RESULTS</b>When infected, both strains of rats experienced an acute infectious stage followed by a recovery. Histological scores were significantly higher in infected rats compared with those of the non-infected controls at day 10 PI (10 day-PI vs. control: +/+: 2.75+/-0.17 vs. 0.42+/-0.09; Ws/Ws: 2.67+/-0.67 vs. 0.50+/-0.34; P<0.01). In +/+ rats, post-infection ACRS induced the formation of low-grade inflammation, represented by the imbalance of IL-1beta and IL-10 (IL-1beta: PI+ACRS vs. control: (1812.24+/-561.61) vs. (1275.97+/-410.21) pg/g, P<0.05; IL-10: PI+ACRS vs. control: (251.9+/-39.8) vs. (255.3+/-24.7) pg/g, P>0.05), accompanied by hyperplasia and activation of mast cells (PI+ACRS vs. control: 58.8+/-19.2 vs. 28.0+/-7.6; P<0.01). The balance between acetylcholine (ACh) and substance P (SP) was also disturbed (ACh: PI+ACRS vs. control: (743.94+/-238.72) vs. (1065.68+/-256.46) pg/g, P<0.05; SP: PI+ACRS vs. control: (892.60+/-231.12) vs. (696.61+/-148.61) pg/g, P<0.05). Nevertheless, similar changes of IL-1beta/IL-10 and ACh/SP were not detected in Ws/Ws rats.</p><p><b>CONCLUSION</b>The imbalance of ACh/SP, together with the activation of mucosal immunity induced by post-infection ACRS were lacking in mast cell deficient rats, which supports the premise that mast cells play an important role in cholinergic and peptidergic remodeling in the ileum of rats.</p>