ABSTRACT
Objective:To evaluate the role of Toll-like receptor 4 (TLR4) in the mechanism by penehyclidine hydrochloride alleviating lipopolysaccharide (LPS)-induced acute lung injury(ALI)in rats.Methods:Twenty-four healthy male Sprague-Dawley rats, aged 10 weeks, weighing 220-250 g, were divided into 4 groups ( n=6 each) according to the random number table method: normal saline group (NS group), endotoxin-induced ALI group (ALI group), penehyclidine hydrochloride + normal saline group (PHC+ NS group) and penehyclidine hydrochloride + endotoxin-induced ALI group (PHC+ ALI group). ALI was induced by intratracheal instillation of LPS 5 mg/kg in anesthetized animals. In group PHC+ ALI, penehyclidine hydrochloride 2 mg/kg was intraperitoneally injected immediately after intratracheal instillation of LPS. The equal volume of normal saline was injected into the airway in group NS, and penehyclidine hydrochloride 2 mg/kg was intraperitoneally injected immediately after intratracheal instillation of normal saline in group PHC+ NS. The rats were sacrificed at 6 h after intratracheal instillation of LPS or normal saline, and lungs were removed. The lung was lavaged and broncho-alveolar lavage fluid (BALF) was collected for determination of concentrations of tumor necrosis factor-alpha (TNF-α) and interleukin-1beta (IL-1β) by enzyme-linked immunosorbent assay. Lung tissues were obtained for microscopic examination of the pathological changes (with a light microscope) and for determination of wet to dry lung weight ratio (W/D ratio) and TLR4 protein and mRNA expression (by immuno-histochemistry or real-time polymerase chain reaction). Results:Compared with group NS and group PHC+ NS, the W/D ratio and concentrations of TNF-α and IL-1β in BALF were significantly increased, the expression of TLR4 protein and mRNA in lung tissues was up-regulated ( P<0.01), and the pathological changes of lung tissues were aggravated in group ALI . Compared with group ALI, the W/D ratio and concentrations of TNF-α and IL-1β in BALF were significantly decreased, the expression of TLR4 protein and mRNA in lung tissues was down-regulated ( P<0.01), and the pathological changes of lung tissues were significantly mitigated in group PHC+ ALI. Conclusions:The mechanism by which penehyclidine hydrochloride reduces endotoxin-induced lung injury may be related to reduction of TLR4 activity and thus inhibition of pulmonary inflammatory responses in rats.
ABSTRACT
0bjective To study the potency of Entecavir Maleate(ETVM),Entecavir(ETV) and Adefovir(ADV) on suppressing duck hepatitis B virus (DHBV) replication.Methods DHBV DNA positive ducks were used as experimental animal model.Ail these ducks were randomized to different arms and respectively given high,medium and low dosage of ETVM,ETV and ADV.ETVM and ETV were given orally daily respectively for six weeks and ADV orally 3 times every week for six weeks.The serum DHBV DNA levels were tested every 2 weeks at day 0 and,after that,at week 2,4.6 and 8 respectively by real-time fluorescent quantitative polymerase chain reaction(PCR).The results were analyzed by paired-samples t test.Results The treatment resulted in the reduction of viral load among all ETVM.ETV or ADV treated groups.The viral load of DHBV DNA at pretreatment and week 6 in the ETVM high dosage group were(7.34±1.33)and(2.12±2.50)lg copy/mL,respectively(P<O.01) and in the ETV high dosage group,the load of DHBV DNA were(8.02±0.56)and(4.36±1.64)lg copy/mL at pretreatment and week 6,respectively (P<0.01).DHBV DNA rebounds were observed after treatment cessation in these groups.The results showed that ETVM and ETV had superior antiviral activity compared tO ADV by rapidly and intensively inhibiting DHBV DNA replication in hepatitis B infected ducks.while the potency of ETVM was even better than ETV.Conclusions Both ETVM and ETV'S antiviral activities are much better than that of ADV while ETVM has the best antiviral efficacy.DHBV animal model is a good model tO screen and evaluate antiviral activity of different drugs and compounds.