肾素原及其受体的研究进展

The renin-angiotension system (RAS) plays an important role in cardiovascular and renal physiology and diseases. Recent discoveries of prorenin and prorenin receptor add new contents to RAS. Renin and prorenin binding to the prorenin receptor not only target and facilitate angiotensin generation but also lead to activation of prorenin receptor signal transduction pathways,which is distinct from classical RAS signaling. In this paper,the construction,function and signal trasduction of prorenin,prorenin receptor and handle region peptide are reviewed.

Development of hepatorenal syndrome in bile duct ligated rats

AIM: To evaluate in bile duct ligated rats whether there were progressive alterations of renal function without changes in histopathology. METHODS: Male Wistar rats were submitted to sham-surgery or bile duct ligation (BDL) and divided according to the post-procedure time (2, 4 and 6-wk). To determine renal function parameters, rats wereplaced in metabolic cages and, at the end of the experiment, blood and urine samples were obtained. Histology and hydroxyproline content were analyzed in liver and renal tissue. RESULTS: Rats with 2 wk of BDL increased free water clearance (P = 0.02), reduced urinary osmolality (P = 0.03) and serum creatinine (P = 0.01) in comparison to the sham group. In contrast, rats at 6 wk of BDL showed features of HRS, including signif icant increase in serum creatinine and reductions in creatinine clearance, water excretion and urinary sodium concentration. Rats with 4 wk of BDL exhibited an intermediate stage of renal dysfunction. Progressive hepatic f ibrosis according to post-procedure time was confirmed by histology. The increased levels of liver hydroxyproline contrasted with the absence of structural changes in the kidney, as assessed by histology and unchanged hydroxyproline content in renal tissue. CONCLUSION: Our data show that BDL produced progressive renal dysfunction without structural changes in the kidney, characterizing HRS. The present model will be useful to understand the pathophysiology of HRS.

Genetic variations of beta 2-adrenergic receptor gene are associated with essential hypertension in Xinjiang Kazakans

Objective The aims of the present study were to investigate the associations of 46 A〉G, 79 C〉G, 491 C〉T and 659 C〉G genetic variants of the human beta 2-adrenergic receptor （β2-AR）, ADRB2, gene with essential hypertension （EH） in Xinjiang Kazakans population.Methods A gender-matched case-control （271 hypertensive cases and 267 normotensive controls） study was used to investigate the associations of the four variations in the coding region of ADRB2 with EH. The genotypes of the variants were identified by the polymerase chain reaction and restriction fragment length polymorphism （PCR-RFLP） methods. Results 46 A〉G, 79 C〉G and 659 C〉G polymorphisms were common in the Kazakan population, but 491 C〉T was a mutation （frequency ofT allele was only 0.003） and only found in EH group. The fxequency distributions of genotypes and alleles for 659 C〉G between the EH and control groups was significantly different （P〈0.05）, while those for 46 A〉G and 79 C〉G polymorphisms were not statistically different. Logistic regression analysis suggested that the G allele of 659 C〉G polymorphism was a risk factor for hypertension （minor allele vs common homo; odds ratio, 13.240, 95% CI, 4.052-43.274; P〈0.05）. Covariance analysis showed that systolic and diastolic blood pressure levels in GG＋CG group of 659 C〉G were significantly higher than those in the CC group, but no significant difference of blood pressure were found between common homo and minor allele for 46 A〉G and 79C〉G polymorphisms. Haplotype analysis showed that two hyplotypes, HI： 46A-79C-491C-523C（48%）and H5：46A-79C-491C-659G, were associated with EH.Conelusion ADRB2 genetic variants may play independent roles in the molecular genetic mechanism of EH in Xinjiang Kazakans population （d Geriatr Cardio12010; 7：52-57）.

LOW MOLECULAR WEIGHT HEPARIN DECREASES THE ALBUMINURIA AND RENAL PATHOLOGICAL CHANGES IN DIABETIC NEPHROPATHY RATS

Objective To investigate the renoprotection effect of low molecular weight heparin(LMWH)in diabetic rats.Methods Diabetic rats were induced by injection of steptozotocin(STZ).Rats were randomly divided into three groups:control group,diabetic model group,and LMWH treatment group.The levels of total cholesterol(TC),triglyceride(TG),prothrombin time(PT),kaolin partial thromboplastin time(KPTT),24-hour urinary albumin excretion rate(UAER),and serum soluble P-selectin were determined after 8 weeks.Glomerular morphology was observed by light microscopy.Results The levels of TG,UAER,and P-selectin in LWMH treatment group were lower than those in model group(all P<0.01).The levels of PT and KPTT in LWMH treatment group were shorter than those in model group.And LWMH improved the histological changes of diabetic rats.Conclusion LMWH has some renal protective effects in diabetic rats,partly through down-regulating the expression of P-selectin.

Aircraft noise exposure affects rat behavior,plasma norepinephrine levels,and cell morphology of the temporal lobe

In order to investigate the physiological effects of airport noise exposure on organisms,in this study,we exposed Sprague-Dawley rats in soundproof chambers to previously recorded aircraft-related noise for 65 d.For comparison,we also used unexposed control rats.Noise was arranged according to aircraft flight schedules and was adjusted to its weighted equivalent continuous perceived noise levels(LWECPN) of 75 and 80 dB for the two experimental groups.We examined rat behaviors through an open field test and measured the concentrations of plasma norepinephrine(NE) by high performance liquid chromatography-fluorimetric detection(HPLC-FLD).We also examined the morphologies of neurons and synapses in the temporal lobe by transmission electron microscopy(TEM).Our results showed that rats exposed to airport noise of 80 dB had significantly lower line crossing number(P<0.05) and significantly longer center area duration(P<0.05) than control animals.After 29 d of airport noise exposure,the concentration of plasma NE of exposed rats was significantly higher than that of the control group(P<0.05).We also determined that the neuron and synapsis of the temporal lobe of rats showed signs of damage after aircraft noise of 80 dB exposure for 65 d.In conclusion,exposing rats to long-term aircraft noise affects their behaviors,plasma NE levels,and cell morphology of the temporal lobe.