Roles of hirudin in protease activated receptor 1 expression changes in basal artery of rat subarachnoid hemorrhage models / 中华神经医学杂志

Objective To discuss the influence of direct thrombin inhibitor hirudin in the expression ofprotease activated receptor 1 (PAR-1) in basilar artery of the rat model with subarachnoid hemorrhage (SAH).Methods Thirty-six Sprague Dawley rats (7 weeks old,clearanimal) were divided into 3 groups randomly:control group (n=12),SAH group (n=12) and SAH+hirudin treatment group (n=12).The rat models of SAH in the later two groups were induced by twice injection blood into the cisterna magna; rats in the SAH+hirudin treatment group also accepted blood with 200 U/mL hirudin.Animal behavior changes were recorded.Rats of different groups were killed on the 7th d of model making,and samples of basilar artery were performed HE staining for histological observation under microscope; vascular changes of cross-sectional area were measured by Image-Pro Plus6.0 imaging analysis software; and PAR-1 expression was detected by immunohistochemistry.Results Larger vascular lumen,thinner wall,smoother lining and no fold in the basal artery of control group were found as compared with thick wall,narrow lumen and endothelial fold in SAH model rats; the changes of basal artery in SAH+hirudin treatment group enjoyed in the medium ranking.The vascular changes of cross-sectional area in the SAH+hirudin treatment group were more obvious than those in the SAH group (P＜0.05); the cross-sectional area in the SAH+hirudin treatment group and SAH group was significantly smaller than that in the control group (P＜0.05).The immunohistochemistry results showed there was no PAR-1 expression in the rats of control group,and PAR-1 positively expressed in the basilar artery of rats in the SAH group and weakly expressed in that of SAH+hirudin treatment group.The PAR-1 absorbance value in the SAH+hirudin treatment group and SAH group was significantly higher than that in the control group; and that in the SAH+hirudin treatment group was significantly lower than that in the SAH group (P＜0.05).Conclusion Hirudin can reduce PAR-1 expression in the basilar artery of SAH rat models and relieve artery vasospasm,which indicates that thrombin may play important roles in the pathological process of cerebral vasospasm after SAH.

Overexpression of sarcoplasmic reticulum calcium ATPase induced hemodynamic and proteomic changes in a dog model of heart failure / 中华心血管病杂志

<p><b>OBJECTIVE</b>Overexpression of SERCA2a could improve cardiac function in human and experimental heart failure (HF) models. We observed the proteomics changes post SERCA2a overexpression in a pacing induced HF model in dogs.</p><p><b>METHODS</b>Beagles were divided into four groups: control group, HF group (230 beats/min for 4 weeks), HF + EGFP group (myocardial injection of 1 x 10(12) v.g recombinant adeno-associated virus carrying enhanced green fluorescent protein gene, rAAV2/1-EGFP) and HF + SERCA2a group (myocardial injection of 1 x 10(12) v.g recombinant adeno-associated virus carrying SERCA2a gene, rAAV2/1-SERCA2a). Thirty days after gene transduction, left ventricular systolic and diastolic functions were measured by echocardiography and invasive hemodynamics in all animals. By use of 2-dimensional gel electrophoresis (2-DE), -500 distinct protein spots were detected in myocardium of all animals. Protein spots observed to be altered between failing and SERCA2a overexpressed hearts were subjected to tryptic peptide mass fingerprinting for identification by MALDI-TOF mass spectrometry in combination with LC/MS/MS analysis.</p><p><b>RESULTS</b>At 30 day after gene transfer, HF signs were significantly reduced, cardiac function [LVSP: (214.72 +/- 31.74) mm Hg (1 mm Hg = 0.133 kPa) vs. (139.32 +/- 36.79) mm Hg, +dp/dt(max): (6779.43 +/- 217.58) mm Hg/s vs. (2746.85 +/- 931.23) mm Hg/s and -dp/dt(max): (-4341.42 +/- 322.02) mm Hg/s vs. (-2531.14 +/- 616.15) mm Hg/s, LVEDP: (21.86 +/- 6.95) mm Hg vs. (59.78 +/- 6.92) mm Hg] significantly improved in HF + SERCA2a dogs than those in HF + EGFP group(all P < 0.05) and parameters were comparable between HF + SERCA2a and control groups. We identified alterations in the expression level of more than 10 proteins in myocardium. These protein changes were observed mainly in two subcellular compartments: the cardiac contractile apparatus and metabolism/energetics.</p><p><b>CONCLUSION</b>These results showed that overexpression of SERCA2a could improve cardiac function accompanied with numerous alterations in protein expressions involved in calcium handling, myofibrils, and energy production in this dog model of chronic heart failure.</p>

Mechanism of oral absorption of panaxnotoginseng saponins / 药学学报

<p><b>AIM</b>To study the mechanism of absorption after oral administration of panaxnotoginseng saponins (PNS).</p><p><b>METHODS</b>Caco-2 cells and rat models were applied to evaluate the degradation of both ginsenoside Rb1 (Rb1) and ginsenoside Rg1 (Rg1) in PNS in gastrointestinal lumen, and the transport mechanism of PNS across the intestinal mucosa, and the barrier function of stomach, intestine and liver involved in absorption process.</p><p><b>RESULTS</b>Rb1 and Rg1 proved to be readily eliminated in stomach, but stable in relatively neutral circumstance. Both Rb1 and Rg1 in PNS, especially for Rb1, degraded significantly in the contents of large intestine. However, both of them kept mainly intact in the contents of small intestine. Uptake of both Rb1 and Rg1 by Caco-2 cell monolayer was inhibited at low temperature, but not by cyclosporine A, and the change in the apical pH showed no pronounced effect. Uptake and transport were non-saturable and increased linearly with increasing of concentrations of Rb1 and Rg1 over the range of concentration tested, which indicated a passive transport. There was no significant difference of absorption characteristic between monomer (Rb1 and Rg1) and mixture (PNS). Uptake amount of Rg1 [(1.07 +/- 0.16) microg x mg(-1) (protein)] (C0 = 1 mg x mL(-1)) in Caco-2 cells was a little higher than that of Rb1 [(0.77 +/- 0.03) microg x mg(-1) (protein)] (C0 = 1 mg x mL(-1)). Meanwhile, apparent permeability coefficient of (5.9 +/- 1.0) x 10(-8) cm x s(-1) (C0 = 1 mg x mL(-1)) for Rb1 and (2.59 +/- 0.17) x 10(-7) cm x s(-1) (C0 = 1 mg x mL(-1)) for Rg1 from apical compartment to basolateral compartment predicted an incompletely absorption. Transports of both Rb1 and Rg1 were not influenced by cyclosporine A. The investigation on the pharmacokinetic behavior of Rb1 and Rg1 after different routes of administration to rats showed that the absolute bioavailability after peroral (po), intraduodenal (id), and portal venous (pv) administration is 0.71% , 2.75% and 65.77% respectively for Rb1, and 3.29%, 6.60% and 50.56% respectively for Rg1.</p><p><b>CONCLUSION</b>Transport across Caco-2 cell monolayer for PNS (include Rb1 and Rg1) is a simple passive diffusion process. No efflux transporters in Caco-2 cells and other components in PNS showed effects on it. The elimination in stomach, large intestine and liver contributed to the low bioavailability of PNS, but the low membrane permeability might be a more important factor dominating the extent of absorption.</p>