ABSTRACT
Objective To study the effects of long-term use of simvastatin on mechanical ventilation induced lung injury.Methods Forty SPF adult male Sprague-Dawley (SD) rats weighing 300-350 g were randomly divided into four groups (n =10,each):normal saline (NS) control group (group A),mechanical ventilation group (group B),simvastatin control group (group C),and simvastatin + mechanical ventilation group (group D).The rats in groups C and D were treated with simvastatin dissolved in 1 mL NS by gavage with a dose of 10 mg/kg,and the rats in groups A and B were treated with the same volume of NS by gavage for 28 days.Half an hour after the last garage,the rats in groups B and D underwent tracheostomy and intubation for 4 hours,and then received a tidal volume of 30 mL/kg with the respiratory frequency of 40 times/min,inspiratory:expiratory ratio of 1:3,and the rats in groups A and C received tracheostomy and intubation,spontaneous breathing for 4 hours.Four hours later rats were sacrificed by abdominal aorta bloodletting,and the lung tissue was harvested for hematoxylin and eosin (HE) staining to observe pathological changes under light microscope.The activity of malondialdehyde (MDA),superoxide dismutase (SOD),and myeloperoxidase (MPO) was determined.The lung wet/dry weight ratio (W/D) and white blood cell (WBC) count in bronchoalveolar lavage fluid (BALF) were determined.The levels of interleukins-6 (IL-6) and tumor necrosis factor-α (TNF-α) in BALF were determined by enzyme linked immunosorbent assay (ELISA).Results Under light microscope,the structure of lung tissue was integrity in groups A and C without obvious edema and inflammatory cells aggregation;the pathological changes in lung tissue in group B was obvious;and the alveolar structure was clear in group D,pulmonary edema and inflammatory cells aggregation were significantly reduced as compared with those of group B.Compared with group A,SOD activity in group B was significantly decreased (U/g:17.97±2.27 vs.28.51 ±4.58,P ＜ 0.01),while MDA,MPO,lung W/D ratio and WBC,IL-6,TNF-α in BALF were significantly increased [MDA (μmol/g):5.40 ± 0.71 vs.3.56 ± 0.55,MPO (U/g):1.26±0.29 vs.0.68±0.12,lung W/D ratio:6.60±0.99 vs.4.84±0.26,WBC (× 109/L):6.59±0.82 vs.2.35±1.31,IL-6 (ng/L):207.11± 18.67 vs.123.17±20.15,TNF-o (ng/L):421.38±36.27 vs.207.15±44.39,all P ＜ 0.01].Compared with group B,SOD activity in group D was significantly increased (U/g:22.05±2.45 vs.17.97±2.27,P ＜ 0.05),MDA,MPO,lung W/D ratio,and WBC,IL-6,TNF-α in BALF were significantly decreased [MDA (μmol/g):3.77±0.55 vs.5.40±0.71,MPO (U/g):0.96±0.14 vs.1.26±0.29,lung W/D ratio:5.16±0.42 vs.6.60±0.99,WBC (× 109/L):3.18± 1.24 vs.6.59±0.82,IL-6 (ng/L):147.90±21.70 vs.207.11 ± 18.67,TNF-α (ng/L):237.16±50.83vs.421.38 ± 36.27,all P ＜ 0.01].There were no significant difference in all parameters between group C and group A.Conclusion The long-term simvastatin treatment could significantly reduce lung injury induced by mechanical ventilation in rats,and its mechanism was related with simvastatin reduced oxidation-antioxidant imbalance and the inflammatory cytokines activity changes.
ABSTRACT
Microalgae is a single-cell organism with the characteristics of high light energy utilization rate, fast growth rate, high-value bioactive components and high energy material content. Therefore, microalgae has broad application prospects in food, feed, bioenergy, carbon sequestration, wastewater treatment and other fields. In this article, the microalgae biotechnology development in recent years were fully consulted, through analysis from the literature and patent. The progress of microalgal biotechnology at home and abroad is compared and discussed. Furthermore, the project layout, important achievements and development bottlenecks of microalgae biotechnology in our country were also summarized. At last, future development directions of microalgae biotechnology were discussed.
Subject(s)
Bibliometrics , Biofuels , Biomass , Biotechnology , Microalgae , Metabolism , WastewaterABSTRACT
Objective To evaluate the effect of long-term use of simvastatin on aquaporin 5 (AQP5) expression in a rat model of ventilator-induced lung injury.Methods Thirty-two adult male Sprague-Dawley rats, weighing 250-280 g, were randomly divided into 4 groups (n=8 each) using a random number table: control group (group C), simvastatin group (group Sim), mechanical ventilation group (group MV) and simvastatin + mechanical ventilation group (group SMV).In C and Sim groups, normal saline 1 ml/d and simvastatin 10 mg · kg-1 · d-1 were injected, respectively, through a gastric tube into stomach for 4 weeks, and then the rats were tracheostomized, and mechanically ventilated, and the animals kept spontaneous breathing for 4 h.In MV and SMV groups, normal saline 1 ml/d and simvastatin 10 mg · kg-1 · d-1were injected, respectively, through a gastric tube into stomach for 4 weeks, and then the rats were tracheostomized, and mechanically ventilated (tidal volume 50 ml/kg) for 4 h.The rats were then sacrificed, and lungs were removed for determination of wet to dry lung weight ratio (W/D ratio), activities of myeloperoxidase (MPO) and superoxide dismutase (SOD), malondialdehyde (MDA) content,and expression of AQP5 protein and mRNA in lung tissues, and for microscopic examination of pathological changes.Results Compared with group C, the W/D ratio, MPO activity, and MDA content were significantly increased, the SOD activity was decreased, and the expression of AQP5 protein and mRNA was down-regulated in group MV (P＜0.01).Compared with group MV, the W/D ratio, MPO activity, and MDA content were significantly decreased, the SOD activity was increased, and the expression of AQP5 protein and mRNA was up-regulated in group SMV (P＜0.01).The pathological changes of lungs were significantly mitigated in group SMV as compared with group MV.Conclusion Long-term use of simvastatin alleviates ventilator-induced lung injury, and the mechanism is related to down-regulated expression of AQP5 in rats.