Underlying anti-hypertensive mechanism of the Mizuhopecten yessoensis derived peptide NCW in spontaneously hypertensive rats via widely targeted kidney metabolomics

The angiotensin-converting enzyme(ACE)inhibitory peptide NCW derived from Mizuhopecten yessoensis has been demonstrated to have significant in vivo anti-hypertensive effects,however,its anti-hypertensive mechanism is still not fully clarified.This study established a UPLC-Q-TRAP-MS/MS-based widely targeted kidney metabolomics approach to explore the changes of kidney metabolic profiles and to clarify the antihypertensive mechanism of peptide NCW in spontaneously hypertensive rats(SHRs).Multivariate statistical analysis indicated that the kidney metabolic profiles were clearly separated between the SHR-NCW and SHRUntreated groups.A total of 85 metabolites were differentially regulated,and 16 metabolites were identified as potential kidney biomarkers,e.g.,3-hydroxybutyrate,malonic acid,deoxycytidine,and L-aspartic acid.The peptide NCW might regulate kidney metabolic disorder of SHRs to alleviate hypertension by suppressing inflammation and improving nitric oxide production under the regulation of linoleic acid metabolism,folate related pathways,synthesis and degradation of ketone bodies,pyrimidine metabolism,β-alanine metabolism,and retinal metabolism.

Effect of Hypertension on Hearing Function,LDH and ChE of the Cochlea in Older Rats

The relationship between the hypertension and the aging process of hearing organ was investigated Twenty Wistar 3-month old rats and 20 Wistar 12-month old rats, 20 spontaneously hypertensive rat stroke-prone (SHRSP) 3-month old rats and 20 SHRSP 12-month old rats free of middle ear infections as observed under otomicroscopy, with normal tympanic membrane and auricle reflex, were selected to be divided into two experimental groups and two control groups respectively The tail artery blood pressure was measured non-invasively The threshold of auditory brainstem response (ABR) was measured by Spirit TM evoked potential meter The LDH and ChE staining in the inner ear was performed and the optical density was analyzed by the HPIAS analysis system The results showed that there was no difference in the ABR thresholds, the activities of LDH and ChE between Wistar 3-month old group and SHRSP 3-month old group ( P >0 05) The mean value of ABR threshold and the activities of LDH and ChE in the Wistar 12-month old group at relevant sections were significantly greater than those in the two 3-month old groups ( P< 0 05), whereas the mean value of ABR threshold and the activities of LDH and ChE in the SHRSP 12-month old group at relevant sections were significantly higher than those in the 3-month old control group ( P< 0 01) It was concluded that presbycusis existed in the Wistar 12-month old group rats The glycogenosis and the abnormal secretion of neural transmitter were discerned after hypertension All the above factors may worsen the aging of the hearing system

AngiotensinⅡor epinephrine hemodynamic and metabolic responses in the liver of L-NAME induced hypertension and spontaneous hypertensive rats

AIM To study hepatic vasoconstriction and glucose release induced by angiotensin(Ang)Ⅱ or Epi in rats with pharmacological hypertension and spontaneously hypertensive rat(SHR).METHODS Isolated liver perfusion was performed following portal vein and vena cava cannulation; AngⅡ or epinephrine(Epi) was injected in bolus and portal pressure monitored; glucose release was measured in perfusate aliquots. RESULTS The portal hypertensive response(PHR) and the glucose release induced by AngⅡ of L-NAME were similar to normal rats(WIS). On the other hand, the PHR inducedby Epi in L-NAME was higher whereas the glucose release was lower compared to WIS. Despite the similar glycogen content, glucose release induced by AngⅡ was lower in SHR compared to Wistar-Kyoto rats although both PHR and glucose release induced by Epi in were similar. CONCLUSION AngⅡ and Epi responses are altered in different ways in these hypertension models. Our results suggest that inhibition of NO production seems to be involved in the hepatic effects induced by Epi but not by AngⅡ; the diminished glucose release induced by AngⅡ in SHR is not related to glycogen content.

Expression of Inositol 1,4,5-trisphosphate Receptor mRNA in Myocardium of Spontaneous Hypertension Rats and Cultured Vascular Smooth Muscle Cells of Rats

Objective\ To investigate expression of inositol 1,4,5 trisphosphate receptor (IP\-3R) mRNA on sacroplasmic reticular in myocardium of spontaneous hypertension rats (SHRs) and cultured vascular smooth muscle cells (VSMC) of rats and effects of perindopril and urapidil on them. Methods\ SHRs were orally given perindopril (1.0 mg·kg\+\{ 1\}·d\+\{ 1\}) or urapidil (15 mg·kg\+\{ 1\}·d\+\{ 1\}) for 24 weeks, respectively. Expression of IP\-3R mRNA was examined by semi quantitative reverse transcription polymers chain reaction (RT PCR) using three oligonuclotide primers for each subtype of IP\-3R with β actin as internal label. Results\ All subtypes of IP\-3R were expressed in myocardium of SHR, WKY and cultured VSMC. Expression of IP\-3R mRNA in left ventricle of SHR was markedly enhanced. Urapidil could down regulate expression of IP\-3R Ⅰand IP\-3R Ⅲ, perindopril slightly increased expression of IP\-3R Ⅱ and decreased expression of IP\-3R Ⅰand IP\-3R Ⅲ in myocardium of SHR. Conclusion\ Our results suggest that expression of IP\-3R mRNA in cardiovascular system could be regulated by urapidil and perindopril.

Epigallocatechin-3-gallate exerts antihypertensive effects and improves endothelial function in spontaneously hypertensive rats

Objective:To investigate the effect of epigallocatechin-3-gallate(EGCG)on endothelial dysfunction in spontaneously hypertensive rats(SHR).Methods:Wistar-Kyoto(WKY)rats and SHR were divided into four groups;WKY control,SHR control and SHR treated with EGCG(50 mg/kg/day)or losartan(10 mg/kg/day).The treatment was given daily for 4 weeks by oral gavage and the blood pressure was monitored by tail-cuff method every 3 days.Acetylcholineinduced endothelium-dependent relaxations were assessed in isolated phenylephrine-precontracted aortic rings at the end of treatment.The vascular levels of reactive oxygen species,nitric oxide,tetrahydrobiopterin,and cyclic guanosine monophosphate were also measured.Moreover,the expression of angiotensinⅡtype 1(AT_(1))receptor protein was determined.Results:The systolic blood pressure was significantly decreased in SHR treated with EGCG.The impaired endothelium-dependent relaxation was significantly improved in aortic ring isolated from the EGCG-treated SHR group.EGCG also significantly increased the levels of nitric oxide,tetrahydrobiopterin,and cyclic guanosine monophosphate,while decreasing the level of reactive oxygen species and the protein expression of AT_(1)receptor in SHR.Conclusions:EGCG attenuates endothelial dysfunction in SHR by decreasing oxidative stress and increasing vascular nitric oxide bioavailability,which may be modulated partly by inhibition of vascular AT_(1)receptors.An increase in endothelium-dependent relaxation may contribute to a decrease in blood pressure in hypertensive animals.

A hippocampal anti-hypertensive mechanism induced by twirling reinforcing-reducing manipulation in rats

Objective:To investigate a hippocampal anti-hypertensive mechanism induced by twirling reinforcingreducing manipulation(TRRM)using proteomics in rats.Methods:Forty-two male spontaneously hypertensive rats were randomly divided into 3 groups,and 14 Wistar-Kyoto rats were served as control group.In the twirling reinforcing(TRF)group,needles were directly inserted into the Taichong(LR 3)point,then thumbs were moved heavily forward and lightly backward for 3 min,while needles remained inserted for 17 min.In the twirling reduction(TRD)group,the same treatment was applied as in the TRF group except that the thumb moved lightly forward and heavily backward.In the model and control groups,only the corresponding grasping and fixation were applied.All interventions were conducted for 14 days.The blood pressure(BP)of all rats was measured one day before intervention and every other day after.Then hematoxylin-eosin(H&E)staining,label-free and parallel reaction monitoring proteomic techniques were used to assess hippocampal samples from each group.Results:Systolic BPs showed a significant decrease in the TRF and TRD groups compared with the model group(P<.01).In the model group,H&E staining showed obvious pathological changes in the hippocampus,while in the TRF and TRD groups,the hippocampal morphology was only slightly altered.Labelfree proteomic analysis revealed 1163 differential protein expressions between groups.Gene Ontology enrichment analysis confirmed that the differentially expressed proteins were enriched in different biological processes,cellular components,and molecular functions.Kyoto Encyclopedia of Genes and Genomes enrichment analysis showed that TRRM proteins were expressed in the serotonergic synapse pathway,renin-angiotensin system,the mitogen-activated protein kinase signaling pathway,and the peroxisome pathway,which were all also related to BP regulation.Conclusion:TRRM can significantly lower the BP of SHRs.The mode of action may be through the activation of various protein pathways in the hippocampus that are related to BP regulation.

Effects of continuous intermedin infusion on blood pressure and hemodynamic function in spontaneously hypertensive rats

Objective To examine the effects of exogenously administered intermedin （IMD,adrenomedullin-2） on arterial blood pressure,cardiac function and the cardiovascular IMD receptor system in spontaneously hypertensive rats （SHRs） as well as to investigate the associated mechanisms.Methods Thirteen week-old male rats were divided in Wistar Kyoto （WKY） group （n =12）,SHR group （n =12）,IMD group （SHRs infused with IMD 1-47 500 ng/kg per hour,n =12）,and ADM group （SHRs infused with adrenomedullin 500 ng/kg per hour,n =12）.Results A two-week continuous administration of low dose IMD 1-47 via mini-osmotic pumps markedly reduced blood pressure,the maximal rates of increase and decrease of left-ventricle pressure development （LV ± dp/dtmax）,left ventricular systolic pressure and heart rate in SHRs.Furthermore,IMD also inhibited protein over-expression of cardiovascular IMD receptors,myocardial Receptor Activity-Modifying Proteins （RAMP1 and RAMP2）,aortic RAMP1,RAMP2,RAMP3,and calcitonin receptor-like receptor （CRLR）;suppressed up-regulation of aortic RAMP1,RAMP2,RAMP3 and CRLR gene expression; and markedly elevated the mRNA abundance of myocardial atrial natriuretic peptide （ANP） and myocardial brain natriuretic peptide （BNP）.Additionally,IMD 1-47 administration in SHRs increased aortic cAMP concentration and reduced myocardial cAMP concentration.Conclusion These findings support the speculation that IMD,as a cardiovascular active peptide,is involved in blood pressure reduction and cardiac function amelioration during hypertension.The mechanism underlying this effect may involve IMD binding of a receptor complex formed by RAMPs and CRLR,and consequential regulation of cAMP levels and other cardiovascular active factors,such as ANP and BNP.

Acupuncture with reinforcing and reducing twirling manipulation inhibits hippocampal neuronal apoptosis in spontaneously hypertensive rats

To observe the effects of different acupuncture manipulations on blood pressure and target organ damage in spontaneously hypertensive rats（SHRs）, this study used the reinforcing twirling method（1.5–2-mm depth; rotating needle clockwise for 360° and then counter clockwise for 360°, with the thumb moving heavily forward and gently backward, 60 times per minute for 1 minute, and retaining needle for 9 minutes）, the reducing twirling method（1.5–2-mm depth; rotating needle counter clockwise for 360° and then clockwise for 360°, with the thumb moving heavily backward and gently forward, 60 times per minute for 1 minute, and retaining needle for 9 minutes）, and the needle retaining method（1.5–2-mm depth and retaining the needle for 10 minutes）. Bilateral Taichong（LR3） was treated by acupuncture using different manipulations and manual stimulation. Reinforcing twirling, reducing twirling, and needle retaining resulted in a decreased number of apoptotic cells, reduced Bax m RNA and protein expression, and an increased Bcl-2/Bax ratio in the hippocampus compared with the SHR group. Among these groups, the Bcl-2/Bax protein ratio was highest in the reducing twirling group, and the Bcl-2/Bax m RNA ratio was highest in the needle retaining group. These results suggest that reinforcing twirling, reducing twirling, and needle retaining methods all improve blood pressure and prevent target organ damage by increasing the hippocampal Bcl-2/Bax ratio and inhibiting cell apoptosis in the hippocampus in SHR.

Long-term modifications of blood pressure in normotensive and spontane-ously hypertensive rats by gene delivery of rAAV-mediated cytochrome P450 arachidonic acid hydroxylase

Arachidonic acid cytochrome P-450 （CYP） hydroxylase 4A isoforms, including 4A1, 4A2, 4A3 and 4A8 in the rat kidney, catalyze arachidonic acid to produce 19/20-Hydroxyeicosatetraenoic acids （20-HETE）, a biologically active metabolite, which plays an important role in the regulation of blood pressure. However, controversial results have been reported regarding the exact role of 20-HETE on blood pressure. In the present study, we used recombinant adenoassociated viral vector （rAAV） to deliver CYP 4A1 cDNA and antisense 4A1 cDNA into Sprague-Dawley （SD） rats and spontaneously hypertensive rats （SHR）, respectively, to investigate the effects of long-term modifications of blood pressure and the potential for gene therapy of hyperténsion. The mean systolic pressure increased by 14.2±2.5 mm Hg in rAAV.4A 1-treated SD rats and decreased by 13.7±2.2 mm Hg in rAAV.anti4A l-treated SHR rats 5 weeks after the injection compared with controls and these changes in blood pressure were maintained until the experiments ended at 24 weeks. In 4A1 treated animals CYP4A was overexpressed in various tissues, but preferentially in the kidney at both mRNA and protein levels. In anti-4Al-treated SHR, CYP4A mRNA in various tissues was probed, especially in kidneys, but 4A l protein expression was almost completely inhibited. These results suggest that arachidonic acid CYP hydroxylases contribute not only to the maintenance of normal blood pressure but also to the development of hypertension. rAAV-mediated anti4A administration strategy has the potential to be used as targeted gene therapy in human hypertension by blocking expression of CYP 4A in kidneys.

Effects of Total Flavonoids ofHippophae RhamnoidesL.on Intracellular Free Calciumin Cultured Vascular Smooth Muscle Cells of Spontaneously Hypertensive Rats and Wistar-Kyoto Rats

To explore the effects of total flavonoids of Hippophae rhamnoides L. （TFH） quercetin （Que） and isorhamnetin （Isor） on the intracellular free calcium （[Ca^2＋]） in vascular smooth muscle cells （VSMC） of spontaneously hypertensive rats （SHR） and Wistar-Kyoto rats （WKY）. Metheds： Fluo 3-acetoxymethylester（Fluo-3/AM） was used to observe the effects of TFH （100mg/L） and its essential monomers, namely Que （10^-4mol/L） and Isor （10^-4mol/L） on changes of [Ca^2＋]1 in cultured SHR and WKY VSMC （abbr. to Ca-SHR ＆ Ca-WKY） following exposure to high K^＋, norepinephrine （NE） and angiotensin Ⅱ （AngⅡ）, and to compare with the effects of verapamil （Ver）. Results： （1） TFH, Que and Isor had inhibitory effects on resting Ca-SHR （P〈0.05）, but had no significant effects on Ca-WKY （P〉0.05）. （2） High K^＋ could increase Ca-SHR more significantly than Ca-WKY （P〈0.05）; TFH, Que and Isor could inhibit the elevation of [Ca^2＋]1 induced by high K^＋ -depolarization, with the effects similar to that of Ver, and the effect on Ca-SHR was more significant than that on Ca-WKY （P〈0.05）. （3） NE and Ang Ⅱ could increase Ca-SHR more significantly than Ca-WKY （P〈0.05）, TFH, Que and Isor had remarkably inhibitory effect on the elevation of Ca-SHR and Ca-WKY induced by NE or Ang Ⅱ. （4） In the absence of extracellular Ca^2＋ , TFH, Que and Isor also had certain inhibitory effect on Ca-SHR and Ca-WKY induced by NE, and the effect on the former was more significant than that on the latter（P〈0.05）. Ceaclusiea： TFH, Que and Isor might decrease the levels of [Ca^2＋], in VSMCs by blocking both voltage-dependent calcium channels （VDC） and receptoroperated calcium channels （ROC） in physiological or pathological state, which may be one of the important mechanisms of their hypotensive and protective effects on target organs in patients with hypertension.

Comparison Between the Effects of 2-Selenium Bridged β-Cyclodextrin and Ebselen on Treating SHRsp Stroke

A glutathione peroxidase（GPX） mimic, 2-selenium bridged β-cyclodextrin（2-SeCD）, was synthesized. In order to examine its role and mechanism in treating stroke we chose stroke-prone spontaneously hypertensive rats（SHRsp） as animal model. 56 SHRsps of 8-week olds were randomly divided into several groups： test groups （low, moderate, high dose of 2-SeCD） and control groups（positive and negative）. After onset of the stroke, the rats in test groups were orally administrated with different amounts of 2-SeCD, the positive control group with ebselen, and the negative control group with drinking water. The treatment lasted two weeks, followed by observation of the rats for 10 days, meanwhile blood pressure, biochemical parameters of plasma, and the contents of nitric oxide（NO） and malondialdehyde（MDA） in plasma and brain were determined. The results show that there were significant differences in contents of NO and MDA in plasma and brain between the test groups（high, moderate dose of 2-SeCD） and negative control group. The NO contents of the test groups were obviously higher than that of the negative control group （P〈0.01）. The MDA contents of the test groups（high, moderate dose of 2-SeCD） were obviously lower than that of the negative control group（P〈0.01）. The mechanism of 2-SeCD in treating stroke was discussed, which maybe related to the increase of NO and the decrease of MDA in plasma and brain tissue, but the exact mechanism should be further studied. Moreover, the tendencies of changes in systolic blood pressure, contents of NO and MDA, and other physiological parameters for the test groups were shown to be much better than the corresponding parameters for the positive group（the group with ebselen）（P〈0.05）, indicating that the treatment effect of 2-SeCD is better than that of ebselen.

The Expression of VIP and SP in the Cochlea of Spontaneously Hypertensive Rats and Its Implication

To investigate the expression of vasoactive intestinal peptide (VIP) and substance P (SP) in the cochlea of spontaneously hypertensive rat (SHR), and to assess the function of VIP and SP in the cochlea following the damage of hypertension, hearing thresholds of ABR were observed and the fixative (4% paraformaldehyde) was pumped through the circulatory system. Adult Wistar rats (3 months, n=20) served as the control group and SHRs (3 months, n=20) as the hypertension group. Bullas were taken out and cochleas were irrigated in vitro with the same fixative. The number of base turn's spiral ganglions in the sections was counted. The expression of VIP and SP were detected by SABC method and the images of the sections were analyzed. The number of base turn's spiral ganglsons in the hypertension group was significantly less than in the normal group (P<0.01). VIP and SP were expressed in the spiral ganglion cytoplasma and stria vascularis of the two groups. There were no significant difference in the expression of VIP and SP in spiral ganglion cytoplasma (P>0.05) between the two groups. However, in stria vascularis the expression of VIP in the hypertension group was higher than in the normal group (P<0.05), and no significant difference in SP was found between the two groups. It was suggested that VIP not only contributed to the regulation of the cochlea microcirculation, but also made the neurotransmitter in the pathway of the auditory system. However, SP made only the neurotransmitter in the pathway of the auditory system.

Yizhining elixation improves sustained attention deficit and impulsiveness of spontaneous hypertensive rats

BACKGROUND： The core symptoms of attention deficit, impulsiveness, hyperactivity of attention deficit hyperactivity disorders （ADHD） can concurrently present in spontaneous hypertensive rats. Neuropathological, biochemical and pharmacological studies also support it. Spontaneous hypertensive rats are one kind of best ADHD animal models, which has been accepted at present. Yizhining elixation can reinforce kidney and calm liver, strengthen spleen and nourish heart, benefit intelligence and focus attention, but its therapeutic effect on treatment of ADHD needs to be further investigated. OBJECTIVE： To observe the effect of Yizhining elixation on the persistent active attention deficit and impulsiveness of rats with spontaneous hypertension. DESIGN： Observational and controlled analysis. SETTING： Department of Pediatrics, the First Affiliated Hospital of Guangzhou University of Chinese Medicine. MATERIALS： Thirty-six male rats with spontaneous hypertension, of clean grade, were involved in this experiment. The involved rats were provided by Shanghai SLAC Laboratory Animal Co., Ltd., and they did not undergo any experiments; Yizhining elixation was composed by Guiban, Shenglonggu, Yuanzhi, Shichangpu, Yejiaoteng, Shudi, Dangshen, Yunling, Fuxiaomai, Wueizi. etc. Crude drug, provided by Outpatient Dispensary, Affiliated Hospital of Guangzhou University of Chinese Medicine, was prepared into water elixation, which contained crude drug of 1.154 g/mL. METHODS： This experiment was carried out in the Department of Pediatrics, First Affiliated Hospital of Guangzhou University of Chinese Medicine between March and July 2005. The involved rats were randomized into 3 groups： Yizhining high dose group, Yizhining low dose group and blank control group, with 12 rats in each. Changes in sustained attention and impulsiveness of rats were detected before and after administration of Yizhining elixation by ＂5-choice serial response time task＂ method. Following above-mentioned training and detection, rats in each group were daily drenched with Yizhining elixation once for 14 days successively. Rats in the Yizhining High-dose and low-dose groups we, e drenched with 12.6 mL/kg and 6.3 mL/kg Yizhining elixation （diluted to 25 mL/kg） respectively, and those in the blank control group were drenched with 12.5 mL/kg normal saline. On the 14^th day after administration, the ratios of correct and immature response of rats were re-detected for 3 days successively by formal detection method for later analysis. The sustained attention of rats was evaluated with ratio of correct response： Ratio of correct response=[times of correct response/（times of correct response ＋ times of incorrect response）]; impulsiveness was evaluated with the ratio of immature response： ratio of immature response=[times of immature response/ （times of correct response＋times of incorrect response＋times of omission＋times of immature response） ]. MAIN OUTCOME MEASURES： The effects of different doses of Yizhining elixation on the sustained attention （ratio of correct response） and impulsiveness （ratio of immature response） of spontaneous hypertensive rats. RESULTS： Thirty-six spontaneous hypertensive rats were involved in the final analysis. The ratio of correct response of rats in the Yizhining high dose and low dose groups after administration was （98.9±2.30）% and （96.6±4.00） %, respectively, which was significantly higher than that before administration [ （80.4±11.5 ） %, （839±8.90） %, P 〈 0.01] and that in the blank control group[ （83.3±6.30） %, P 〈 0.01]. The ratio of immature response of rats in the Yizhining high dose and low dose groups after adminisWafion was （5.04 ±1.04 ） %, （7.23 ± 1.22 ） %, respectively, which was lower than that before administration [ （9.85 ±2.50） %, （9.40±1.73 ） %, P 〈 0.05] and that in the blank control group [ （ 9.42 ±1.64） %, P 〈 0.01 ]. CONCLUSION： Yizhining elixation can improve the sustained attention and impulsiveness of spontaneous hypertensive rats.

Effect of Salvia Miltiorrhiza Bge on Left Ventricular Hypertrophy and the Expression of Tumor Necrosis Factor-α in Spontaneously Hypertensive Rats

The effects of salvia miltiorrhiza Bge (SMB) on left ventricular hypertrophy (LVH) and the expression of tumor necrosis factor-α (TNF-α) in the left ventricle of spontaneously hypertensive rats and the action mechanism were investigated. Normal Wistar-kyoto (WKY) rats were used as negative control, and spontaneously hypertensive rats (SHR) were randomly assigned to receive pla- cebo or SMB. SMB (1 g/kg·d) was injected intraperitoneally for 12 weeks. Systolic blood pressure (SBP) and left ventricular mass index (LVMI) were measured. HE, VG and immunohistochemical staining combined with computed morphometry were employed to evaluate the cardiomyocyte size, diameter, the collagen volume fraction (CVF), perivascular circumferential area (PVCA), and tumor necrosis factor-α (TNF-α) expression in the left ventricular tissue. The results showed, as compared with WKY rats, the SBP, LVMI, cardiomyocyte size, diameter, CVF, PCVA, and TNF-α expression were increased markedly in the 20-week-old spontaneously hypertensive rats. SMB decreased LVMI (P<0.01), size of cardiomyocytes (P<0.01), collagen volume fraction (P<0.01), perivascular circum- ferential area (P<0.01), and TNF-α expression (P<0.01), but had no effect on SBP (P>0.05). It was suggested that chronic administration of SMB could inhibit and reverse the development of LVH in spontaneously hypertensive rats independent of BP. TNF-α may be involved in the reversal mecha- nism of LVH by SMB.

Radioimmunoassay of Antiarrhythmic Peptide and Its application

To establish a specific and sensitive radioimmunoassay (RIA) for antiarrhythmic peptide (AAP) and study serum AAP levels in normal Sprague-Dawley rats (NR) and spontaneous hypertension rats (SHR), AAP-bovine serum albumin (BSA) conjugate was prepared by ammonium bicarbonate method. The New Zealand rabbits were immunized by administering intradermally the conjugate. Then the rabbit anti-AAP serum was produced and iodinated AAP was made by Bolton-Hunter method. The RIA for serum AAP was set up and serum AAP levels in NR and SHR were determined. The minimal detectable range of the AAP RIA was (0.45±0.06) μg/L. The affinity constant for antiserum was 1.05×10 9 L/mol, and the rate of cross-reactivity with atrial peptide (AP) and human growth hormone (hGH) were 0.12 % and 0.20 %, respectively. The mean recovery rate of high, medium and low doses was 97.6 %, and the mean coefficients of variation for intra- and interbath-assay were (6.43±0.85) % and (9.62±1.04) %, respectively. The mean levels of AAP in NR with different age (3 months, 8-10 months and 18-20 months) were (1.75±0.13) μg/L, (1.74±0.11) μg/L and (1.79±0.15) μg/L, respectively, while those in SHR with different age (3 months, 8-10 months and 18-20 months) were (2.38±0.35) μg/L, (2.54±0.25) μg/L and (2.83±0.21) μg/L, respectively. The levels of serum AAP showed a positive correlation with blood pressure (r=0.8667, P<0.05). It was indicated that this AAP RIA had high specificity, high accuracy and good reproducibility. The levels of serum AAP had a close relation with blood pressure.

Effect of 2-Selenium Bridged β-Cyclodextrin,Glutathione Peroxidase Mimic on Stroke of Stroke-prone Spontaneously Hypertensive Rats

To investigate the treatment effect of 2-selenium bridged β -cyclodextrin(2-SeCD),a GPX mimic,on the stroke of stroke-prone spontaneously hypertensive rats(SHRSP),fifty-two SHRSP of 8-week old were randomly divided into four groups A,B,C and control group D. The rats of groups A,B,C and D were given 1.0%-1.5% NaCl mass fraction as drinking fluid. After onset of stroke,groups A,B and C were given \{orally\} 16.05,160.5 and 1605 mg·kg -1 ·day -1 of 2-SeCD,respectively,and group D was given water for \{2 weeks.\} The clinical score of stroke,systolic blood pressure(SBP),survival time of rats were recorded and the histopathologic examinations of their brain and carotid artery were made after decapitation. The clinical scores of stroke after treatment with 160.5 mg·kg -1 ·day -1 (Group B) and 1605 mg·kg -1 ·day -1 (Group C) of 2-SeCD are 2.55±0.98 and 1.98±0.79,respectively,those are obviously lower than that of group D(3.41±0.83,p<0.01). The survival days in group B(10.0±8.6) and group C(14.4±7.9) are longer than that for group D(4.7±2.9,p<0.01). The electron microscope study showed that the endothelium of carotid artery was near to normal in group B and group C,while it was seriously injured in control group D and mildly injured in group A. 2-SeCD may effectively be used to treat the stroke for SHRSP.

Telmisartan Attenuates the Growth of Epithelium-like Cells and Glomerular Injury in Spontaneously Hypertensive Rats

The abnormal growth of epithelium-like cells has been noticed in spontaneously hypertensive rats(SHRs)with hypertensive nephropathy.However,the characteristics of abnormal epithelium-like cells and their pathogenesis in hypertensive nephropathy are not fully understood.In the present study,we investigated the correlation of epithelium-like cells with glomerular injury,and the effects of early drug intervention with telmisartan,an anti-hypertensive drug,on the growth of epithelium-like cells.The results showed that the epithelium-like cells were obviously observed lining along the luminal surface of Bowman’s capsule in glomeruli,significantly resulting in the atrophy of the glomerular tuft.Some of the epithelium-like cells strongly expressed proliferating cell nuclear antigen(PCNA)and vimentin,indicating active cellular proliferation.The incidence of epithelium-like cells varied from 13.6%to 54.4%of glomeruli in 48-week-old SHRs,and from 5.1%to 18.0%of glomeruli in age-matched Wistar-Kyoto(WKY)rats(P<0.01).The linear regression analysis further confirmed an obvious correlation between the incidence of epithelium-like cells and the glomerular injury.Moreover,early intervention with telmisartan could dramatically attenuate the progression of epithelium-like cells growth.However,no significant effect of telmisartan on the established epithelium-like cells was observed.Taken together,we demonstrated the involvement of abnormal epithelium-like cells growth in glomerular injury during hypertensive nephropathy in SHRs,and firstly showed the positive effects of the anti-hypertensive drug on the progression of epithelium-like cells growth.

Effect of Salvia Miltiorrhiza on Left Ventricular Hypertrophy and Cardiac Aldosterone in Spontaneously Hypertensive Rats

Chronic treatment with Salvia Miltiorrhiza preventing left ventricular hypertrophy (L VH) and its possible mechanism- inhibiting the action of cardiac aldosterone in spontaneously hypertensive rats (SHR) were investigated.Normotensive Wistar- kyoto (WKY ) rats and SHRs were used.Part of SHRs was treated with Salvia Miltiorrhiza for 12 weeks.Systolic blood pres- sure (SBP) and left ventricular mass index were measured.Sections of heart tissue were stained with HE method and Van Gieson method.Collagen volume fraction was determined in the leftven- tricle by automatically quantitative m orphometry.Cardiac aldosterone concentration was measured by radioimm unoassay.The results indicated thatcom pared with WKY rats,SHRs exhibited high- er SBP,left ventricular collagen volume fraction,and aldosterone concentration (all P<0 .0 5 ) . After the treatm ent with Salvia Miltiorrhiza,SBP,left ventricular collagen volum e fraction,and aldosterone concentration in SHR were decreased as compared with control group (P<0 .0 5 ) ex- cept SBP.It was concluded thatchronic treatment with Salvia Miltiorrhiza could preventleftven- tricular hypertrophy in SHR,significantly inhibit collagen compositions in left ventricle.The m echanism was probably related with the inhibition of the cardiac aldosterone action.

Effects of "Plateau Bright Pearl" Green Tea on Blood Pressure,Myocardial Ultrastructure and Plasma Angiotensin Ⅱ ( Ang Ⅱ) Content in Spontaneous Hypertensive Rats

[Objective] This study aimed to further explore the relationship between tea and health. [Method] Different experimental groups were designed to preliminarily investigate the effects of ＂Plateau Bright Pearl＂ commixed green tea on blood pressure, myocardial ultrastructure and level of plasma angiotensin Ⅱ （Ang Ⅱ） in spontaneous hypertensive rats. [Result] The results showed that ＂Plateau Bright Pearl＂ commixed green tea could significantly decrease blood pressure and level of plasma angiotensin Ⅱ （ang Ⅱ） in spontaneous hypertensive rats and improve ultrastructures of left ventricular mitochondrion and myofibrillae. [Conclusion] ＂Plateau Bright Pearl＂ commixed green tea has many physiological health functions including losing weight, protecting the heart and lowering blood pressure.

POTENT HYPOTENSIVE EFFECTS OF ORPHANIN FQ IN CONSCIOUS STROKE-PRONE SPONTANEOUSLY HYPERTENSIVE RATS

Orphanin FQ（OFQ） or nociceptin is a novel neuropeptide consisting of 17 amino acids. This peptide has a primary structure reminiscent of that of opioid peptide but exhibits an opposite effect to make animals hyperreactive. The effect of this new peptide on cardiovascular function are not completely known. The present study was conducted to investigate the effect of intravenous bolus injection of orphanin FQ on mean arterial blood presure （MABP） in conscious stroke-prone spontaneously hypertensive rats (SHRsp). Adult male SHRsp and Wistar normotensive rats （250～300 g body weight, 2. 5～3 months old） were used in this study. The MABP was measured in the conscious state by a tail-cuff method. In SHRsp model, intravenous bolus injection of orphanin FQ or Tyr1-orphanin FQ （0. 5 mg/kg） induced a prolonged and marked reduc- tion in MABP. The maximum changes in MABP were -30. 2±4. 2 mmHg by orphanin FQ and -28. 2± 4. 7 mmHg by Tyr1-orphanin FQ at 10 min after administration,and this effect lasted over 30 min. The Phe1→Tyr substitution in orphanin FQ was found to retain almost fully hypotensive activity. Pretreatment of SHRsp with naloxone-HCI（60 μg/kg）, 5 min before the injection of orphanin FQ, did not block the hy- potensive effect of orphanin FQ. Therefore, opioid receptors could not account for the hypotensive effect of orphanin FQ in SHRsp. In Wistar rats, intravenous bolus injection of the same dose of orphanin FQ did not cause a change in MABP. These observations suggest that orphanin FQ is a novel hypotensive peptide and may have some role in the regulation of blood pressure in SHRsp, rather than in normotensive rats. The ex-act underlying mechanisms are waiting to be clarified.