Effect and mechanism of leonurine on pressure overload-induced cardiac hypertrophy in rats / 中国中药杂志

To investigate the effects of leonurine(Leo) on abdominal aortic constriction(AAC)-induced cardiac hypertrophy in rats and its mechanism. A rat model of pressure overload-induced cardiac hypertrophy was established by AAC method. After 27-d intervention with high-dose(30 mg·kg~(-1)) and low-dose(15 mg·kg~(-1)) Leo or positive control drug losartan(5 mg·kg~(-1)), the cardiac function was evaluated by hemodynamic method, followed by the recording of left ventricular systolic pressure(LVSP), left ventricular end-diastolic pressure(LVESP), as well as the maximum rate of increase and decrease in left ventricular pressure(±dp/dt_(max)). The degree of left ventricular hypertrophy was assessed based on heart weight index(HWI) and left ventricular mass index(LVWI). Myocardial tissue changes and the myocardial cell diameter(MD) were measured after hematoxylin-eosin(HE) staining. The contents of angiotensin Ⅱ(AngⅡ) and angiotensin Ⅱ type 1 receptor(AT1 R) in myocardial tissue were detected by ELISA. The level of Ca~(2+) in myocardial tissue was determined by colorimetry. The protein expression levels of phospholipase C(PLC), inositol triphosphate(IP3), AngⅡ, and AT1 R were assayed by Western blot. Real-time quantitative PCR(qRT-PCR) was employed to determine the mRNA expression levels of β-myosin heavy chain(β-MHC), atrial natriuretic factor(ANF), AngⅡ, and AT1 R. Compared with the model group, Leo decreased the LVSP, LVEDP, HWI, LVWI and MD values, but increased ±dp/dt_(max) of the left ventricle. Meanwhile, it improved the pathological morphology of myocardial tissue, reduced cardiac hypertrophy, edema, and inflammatory cell infiltration, decreased the protein expression levels of PLC, IP3, AngⅡ, AT1 R, as well as the mRNA expression levels of β-MHC, ANF, AngⅡ, AT1 R, c-fos, and c-Myc in myocardial tissue. Leo inhibited AAC-induced cardiac hypertrophy possibly by influencing the RAS system.

Protection effect of Corn Shuang on hyperlipidemic rats vascular wall / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To study the protection of Corn Shuang on hyperlipidemic rats vascular wall and its mechanism of action.</p><p><b>METHODS</b>Thirty Wistar rats were randomly divided into control group, model group and test group (n = 10). Feeding rats according to the experiment requirement, after 15 weeks,the content of lipids, superoxide dismutase (SOD), serum glutathione peroxidase (GSH-Px), malondialdehyde (MDA), nitric oxide (NO) and nitric oxide synthase (NOS) were measured in each group rats serum, morphological changes of rat aortic wall tissue were observed by light microscopy.</p><p><b>RESULTS</b>The concentration of total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL-C) and MDA increased significantly in model group (P < 0.01), the concentration of high density lipoprotein (HDL-C), SOD, GSH-Px, NO and NOS decreased significantly (P < 0.01); Corn Shuang could reduce the concentration of TC, TG, LDL-C and MDA in hyperlipidemia rats serum (P < 0.01), promote the content of HDL-C, SOD, GSH-Px, NO and NOS (P < 0.01); Aortic wall showed typical atherosclerotic lesion in model group; Corn shuang could improve significantly damages of artery wall.</p><p><b>CONCLUSION</b>Corn Shuang had obvious protective effect on the vessel wall, its mechanism might be related to regulation of blood lipid, antioxidant, maintenance of NO metabolism.</p>

Microstructural observation of epileptic neurons in vitro by atomic force microscopy / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the microstructure of the cell membrane of epileptic neurons using atomic force microscopy (AFM).</p><p><b>METHODS</b>Model of epileptic neurons was established by subjecting the neurons culture for 14 days in vitro to magnesium-free media treatment for 3 h. Patch clamp technique was applied to record the electrophysiological activity of the epileptic neurons. AFM was performed to observe and measure the microstructure of the cell membrane of the epileptic neuron.</p><p><b>RESULTS</b>After a 3-hour treatment with magnesium-free media, the epileptic neurons displayed sustained epileptiform discharge, which continued after the neurons were returned to normal medium culture on day 14. Under AFM scanning size of 80 microm x 80 microm and 2 microm x 2 microm, no obvious difference in the morphology of the cell membrane was noted between epileptic and normal neurons; under the scanning size of 500 nm x 500 nm, small pits occurred in the cell membrane in both groups, but no significant difference was found in the dimension of the pits between the two groups (the diameter and depth of the pits was 114.86-/+9.33 nm and 5.71-/+0.69 nm in epileptic neurons, and 116.4-/+9.13 nm and 5.69-/+0.71 nm in the control neurons, respectively, P>0.05).</p><p><b>CONCLUSION</b>AFM provides a new method for observing neuronal membrane microstructure at nanometer resolutions. No significant alterations occur in the membrane of the neurons after a 3-hour magnesium-free media treatment.</p>

Cloning for Full-length Pyruvate Orthophosphate Dikinase Gene of Sugarcane / 中国生物工程杂志

Compared with C3 plant,C4 plant had evident growth advantage,higher rates of water and nutrition using,and higher bio-yield than C3 plant,Sugarcane was one of the typical C4 plants.DNA was extracted from sugarcane leaves,primers were designed by the cDNA sequence of PPDK gene from GenBank.Then DNA was amplified by LA-PCR(Long Acute PCR) method,ligated into pMD18-T vectors,and transformed into E.coli.JM109.Full-length PPDK gene sequence of sugarcane was obtained,the sequence was 13.5kb in length.For convenient of the next experiment,two digest sites(XhoI and NotI) were introduced into primers,the full-length PPDK gene was splitted to two parts,and was ligated into pMD18-T simple vectors,respectively.Whole PPDK gene clone of sugarcane was finished.The strains were storaged in the lab.