Campanumoea javanica Bl. activates the PI3K/AKT/mTOR signaling pathway and reduces sarcopenia in a T2DM rat model

Objective: Sarcopenia causes loss of skeletal muscle and function, thus seriously affecting the physical function and quality of life in the elderly. This article discusses the specific molecular mechanism and ameliorating effects of Tudangshen(TDS) on sarcopenia in elderly rats with type 2 diabetes mellitus(T2DM).Methods: Elderly Sprague-Dawley(SD) rats were randomly selected and fed with a high-fat diet combined with an intraperitoneal injection of streptozotocin to establish T2DM model. The model rats were stratified and randomly divided into the model group,metformin group, TDS high-dose group, TDS medium-dose group, and TDS low-dose group according to blood glucose combined with body weight, and the same batch of old SD rats was set as the normal control group. The effects of TDS in an elderly T2DM sarcopenia rat model were evaluated by observing the body positions of the rats, analyzing blood biochemistry, testing exercise capacity, and pathologically staining sectioned gastrocnemius muscle tissues. The molecular mechanisms of the effects were analyzed using quantitative real-time polymerase chain reaction and western blotting.Results: TDS has no statistically significant effect on blood glucose, insulin and glycosylated serum protein in aged rats with T2DM, but it can reduce levels of glycosylated serum protein, total cholesterol, triglycerides, and low-density lipoprotein;it improves pathological changes in rat gastrocnemius muscle tissues, and increases muscle cell activity in elderly rats with T2DM and sarcopenia. TDS also promoted the upregulation of the expression of mammalian target of rapamycin(mTOR)/protein kinase B(PKB/AKT)/phosphatidylinositol 3-kinase(PI3K)/ribosomal protein S6 kinase/eukaryotic initiation factor 4 E binding rotein1 mRNA in rats and triggered an increase in corresponding protein levels.Conclusions: TDS alleviated muscle decline in elderly rats with T2DM by activating the PI3 K/AKT/mTOR signaling pathway and regulating the synthesis of corresponding proteins.

Pb Distribution and Sources in Jiaozhou Bay, East China

We studied the distribution, seasonal change, translocation, and source of heavy metal Pb based on the surface and bottom water sampling in Jiaozhou Bay in 1980 in order to know the condition of Pb before the industrial and agricultural development and to probe the distribution and translocation process of Pb. The results show that the range of Pb content in the surface in the whole bay was 0.07-2.71 μg/L, being below Grade Ⅱ of the China’s national water quality benchmark (5.00 μg/L). No Pb pollution was detected in the inner bay, while in the outer bay and the mouth, light Pb pollution. The Pb pollution in the bay waters was area sources. Horizontal and vertical distribution, and seasonal change indicated the translocation of Pb in the waters. Pb entered the water body at marine surface and sank at the marine bottom. Understanding the variable process of Pb in the bay provided the scientific clues for controlling Pb pollution from the human activities.

Rotifer community structure and its response to environmental factors in the Backshore Wetland of Expo Garden,Shanghai

We investigated rotifer community structure in the Backshore Wetland of the Expo Garden in Shanghai from September 2009 to August 2010.We identified 116 rotifer species,determined the dominant species and their relationships with environmental factors,and community diversity indices.Polyarthra trigla was the most common species over the four seasons and proportionally most dominant in spring and autumn,whereas Cephalodella exigua and Keratella cochlearis were the most dominant species in winter and summer,respectively.There was seasonal variability in species numbers,with the highest numbers in summer,followed by autumn and winter.The mean annual density was 815±1346 ind./L and the biomass was 0.3649±0.4940 mg/L.There were significant differences between months:the highest density(2723±2926 ind./L)and biomass(0.7938±0.8197 mg/L)occurred in June,while the lowest density(238±271 ind./L)and biomass(0.0476±0.0429 mg/L)occurred in May.Canonical correspondence analysis(CCA)indicated that temperature,pH,nitrite nitrogen(NO2-N),and total phosphorus(TP)were the most important abiotic factors affecting rotifer distribution.Our research showed that the adaptability of the rotifers to temperature was the important factor.