Earthworm Protein Protects Vascular Endothelial Function in Spontaneously Hypertensive Rats via PI3K/Akt/Nrf2 Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo observe the effect of earthworm protein on the expression of phosphatidylinositol 3-kinase/protein kinase B/nuclear factor E2-related factor 2 （PI3K/Akt/Nrf2） pathway in the aorta of spontaneously hypertensive rats （SHR） and explore mechanism of earthworm protein in treating hypertensive vascular endothelial dysfunction （VED）. MethodTen 10-week-old Wistar Kyoto （WKY） rats and fifty SHR rats were selected for a week of adaptive feeding. WKY rats were selected as the normal group， and fifty SHR rats were randomized according to body weight into model， valsartan （8×10-3 g·kg-1·d-1）， and high-， medium-， and low-dose （0.2， 0.1， 0.05 g·kg-1·d-1， respectively） earthworm protein groups. The normal and model groups were administrated with equal volume of double distilled water by gavage. During the drug intervention period， the general situations of rats in each group were observed and their blood pressure was monitored at specific time points every other week before and after administration. After 8 weeks of drug intervention， enzyme-linked immunosorbent assay was employed to measure the levels of angiotensin-Ⅱ （Ang-Ⅱ） and endothelin-1 （ET-1） in the serum of rats in each group. The corresponding kits were used to determine the levels of nitric oxide （NO）， malondialdehyde （MDA）， glutathione peroxidase （GPX）， superoxide dismutase （SOD）， and ferrous ion （Fe2+）. Hematoxylin-eosin （HE） staining was employed to observe the changes in the intima of the aorta. Fluorescence quantitative polymerase chain reaction （Real-time PCR） was employed to measure the mRNA levels of PI3K， Akt， Nrf2， heme oxygenase-1 （HO-1）， and glutathione peroxidase 4 （GPX4） in the aortic tissue. Western blotting was used to determine the protein levels of p-PI3K （Tyr467/199）， PI3K， p-Akt （Ser473）， Akt， Nrf2， HO-1， and GPX4 in the thoracic aorta. ResultCompared with the normal group， the model group had decreased body mass， increased irritability， severe endothelial damage， elevated blood pressure and serum levels of Ang-Ⅱ， ET1， MDA， and Fe2+ （P<0.01）， lowered NO level （P<0.01）， and down-regulated mRNA and protein levels of p-PI3K （Tyr467/199）， PI3K， p-Akt （Ser473）， Akt， Nrf2， HO-1， and GPX4 in the aortic tissue （P<0.01）. Compared with the model group， drug intervention caused no significant change in the body mass， calmed the rats， alleviated the endothelial damage， lowered blood pressure and serum levels of Ang-Ⅱ， ET1， MDA， and Fe2+ （P<0.01）， elevated the NO level （P<0.05）， and up-regulated the mRNA and protein levels of p-PI3K （Tyr467/199）， PI3K， p-Akt （Ser473）， Akt， Nrf2， HO-1， and GPX4 （P<0.05）. ConclusionThe earthworm protein can exert antihypertensive effects by ameliorating VED in SHR. Specifically， it may regulate the PI3K/Akt/Nrf2 signaling pathway to inhibit oxidative stress and ferroptosis.

Role and mechanism of PKCs in midazolam-induced relaxation of aortic smooth muscle in spontaneously hypertensive rats / 中国药理学通报

Aim To investigate the effect of protein kinase C (PKCs) on midazolam-induced relaxation of aortic smooth muscle in spontaneously hypertensive rats (SHR) and the underlying mechanism. Methods U-sing the isolated vessel tension measurement system, the relaxant effect of midazolam on aortic smooth muscle of SHR and Wistar-Kyoto (WKY) rats was observed. After preincubation with GF109203X (GF, a broad-spectrum inhibitor of PKCs), LY333531 (LY, PKCp2 specific inhibitor) and PKC6 pseudo-substrate inhibitor (PPS), the changes of midazolam-induced relaxation amplitude were observed. Western blot was used to detect the effect of midazolam on the phosphorylation level of PKC [32 in SHR aortic smooth muscle. The effect of midazolam, LY, GF and PPS on the phosphorylation level of the key proteins (CPI-17/ MYPT1/MLC) in calcium sensitization pathway in SHR aortic smooth muscle was also examined. Results Midazolam concentration-dependently relaxed aortic smooth muscle in SHR and WKY. GF significantly inhibited midazolam-induced relaxation amplitude of SHR and WKY aortic smooth muscle. LY and PPS had no significant effect on midazolam-induced relaxation amplitude of WKY aortic smooth muscle. In contrast, LY markedly inhibited midazolam-induced relaxation amplitude of SHR aortic smooth muscle. Midazolam significantly inhibited the phosphorylation level of PKC [32 enhanced by NE in SHR aortic smooth muscle. Midazolam, LY and GF all evidently inhibited the phosphorylation level of the key proteins in calcium sensitization pathway enhanced by NE in SHR aortic smooth muscle. Conclusions Midazolam induces excessive relaxation of SHR aortic smooth muscle by inhibiting calcium sensitization pathway mediated by PKC [32.

Mangiferin alleviates renal inflammatory injury in spontaneously hypertensive rats by inhibiting MCP-1/CCR2 signaling pathway / 中草药·英文版

OBJECTIVE@#Hypertension is a low-grade inflammation state of the disease and was easily complicated by kidneys' inflammatory response. Mangiferin (MGF), a pharmacologically active compound in various plants including Mangifera indica, has a strong anti-inflammatory activity. However, the effects of MGF on renal inflammatory injury in spontaneously hypertensive rats (SHRs) remain unclear. The purpose of this study was to investigate the protective effects and mechanisms of MGF on renal inflammatory injury in SHRs.@*METHODS@#MGF was used in SHRs at the doses of 10, 20, 40 mg/kg/d for 8 weeks consecutively. The blood and urine were collected for assessment of renal function. Renal tissues were collected for histological, immunohistochemistry, ELISA, Western blot and real time reverse transcription PCR (RT-PCR) analysis.@*RESULTS@#The results showed that the levels of interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1) and recombinant chemokine C-C-Motif receptor 2 (CCR2) were increased in SHRs, meanwhile, the level of IL-10 was decreased in SHR. Treatment of MGF inhibited the expression of IL-6, TNF-α, MCP-1 and CCR2, and promoted the expression of IL-10. Furthermore, the content of blood urea nitrogen (BUN) and serum uric acid (SUA) was significantly increased in the model group, and treatment of MGF had no obvious effects on these parameters at all dose levels.@*CONCLUSION@#Our study proved that the kidneys of SHRs had significant inflammatory injury, and MGF had the protective effects on renal inflammatory injury in SHRs; The protective mechanism may be mediated partly by the MCP-1/CCR2 signaling pathway. Thus, it is a potential new drug for the treatment of hypertension.

Intermittent heat exposure induces thoracic aorta injury in spontaneously hypertensive rats by activating the AMPK/mTOR/ULK1 pathway / 南方医科大学学报

OBJECTIVE@#To investigate the effects of different manners of heat exposure on thoracic aorta injury in spontaneously hypertensive rats (SHRs) and explore the underlying mechanism.@*METHODS@#Normal 6 to 7-week-old male SHRs were randomized into control group (cage at room temperature), intermittent heat exposure group (SHR-8 group, exposed to 32 ℃ for 8 h daily for 7 days) and SHR-24 group (with continuous exposure to 32 ℃ for 7 days). After the treatments, the pathologies of the thoracic aorta of the rats were observed with HE staining, and the expressions of Beclin1, LC3B and p62 were detected with Western blotting and immunofluorescence assay; TUNEL staining was used to observe cell apoptosis in the thoracic aorta, and the expressions of caspase-3, Bax, and Bcl-2 were detected using Western blotting. The effects of intraperitoneal injections of 3-MA (an autophagy agonist), rapamycin (an autophagy inhibitor) or compound C 30 min before intermittent heat exposure on the expressions of proteins associated with autophagy, apoptosis and the AMPK/mTOR/ULK1 pathway in the aorta were examined with immunohistochemistry.@*RESULTS@#In SHR-8 group, the rats showed incomplete aortic intima with disordered cell distribution and significantly increased expressions of Beclin1, LC3II/LC3I and Bax, lowered expressions of p62 and Bcl-2, and increased apoptotic cells in the thoracic aorta (P < 0.05). Pretreatment with 3-MA obviously inhibited the expressions of autophagy- and apoptosis-related proteins, whereas rapamycin promoted their expressions. Compared with the control group, the rats in SHR-8 group had significantly down-regulated p-mTOR and up-regulated p-AMPK and p-ULK1 expression of in the aorta; Treatment with compound C obviously lowered the expressions of p-AMPK and p-ULK1 and those of LC3B and Beclin1 as well.@*CONCLUSION@#In SHRs, intermittent heat exposure causes significant pathologies and promotes autophagy and apoptosis in the thoracic aorta possibly by activating the AMPK/mTOR/ULK1 pathway.

Involvement of Interleukin-1 β/Insulin-Like Growth Factor 1 in Ameliorating Effects of Electroacupuncture on Myocardial Fibrosis Induced by Essential Hypertension / 中国结合医学杂志

OBJECTIVE@#To investigate the effect of electroacupuncture (EA) at Neiguan (PC 6) on myocardial fibrosis in spontaneously hypertensive rats (SHRs), and to explore the contribution of interleukin-1 β (IL-1 β), insulin-like growth factor 1 (IGF-1), and transforming growth factor β 1 (TGF- β 1) to the effects.@*METHODS@#Nine 12-weeks-old Wistar Kyoto (WKY) male rats were employed as the normal group. Twenty-seven SHRs were equally randomized into SHR, SHR+EA, and SHR + sham groups. EA was applied at bilateral PC 6 once a day 30 min per day in 8 consecutive weeks. After 8-weeks EA treatment at PC 6, histopathologic changes of collagen type I (Col I), collagen type 1 (Col 1) and the levels of IGF-1, 1L-1 β, TGF- β 1, matrix metalloproteinase (MMP)-2 and MMP-9 were examined in myocardial tissure respectively.@*RESULTS@#After 8-weeks EA treatment at PC 6, the enhanced myocardial fibrosis in SHRs were characterized by the increased mean fluorescence intensity of Col I and Col 1 in myocardium tissue (P<0.01). All these abnormal alterations above in SHR + EA group was significantly lower compared with the SHR group (P<0.01). Meanwhile, the increased levels of IL-1 β, IGF-1, TGF-β 1 in serum or myocardial tissue of SHRs, diminished MMP 9 mRNA expression in SHRs were also markedly inhibited after 8 weeks of EA treatment (P<0.05 or P<0.01). Furthermore, the contents of IL-1 β, IGF-1, TGF-β 1 in myocardial tissue were positively correlated with the systolic blood pressure and hydroxyproline respectively (P<0.01).@*CONCLUSION@#EA at bilateral PC 6 could ameliorate cardiac fibrosis in SHRs, which might be mediated by regulation of 1L-1 β/IGF-1-TGF- β 1-MMP9 pathway.

Sacubitril/valsartan reduces susceptibility of atrial fibrillation by reversing structural remodeling of atrial in spontaneously hypertensive rats / 中国药理学通报

Aim To observe the effects of sacubitril/valsartan (Sac/Val, LCZ696) on atrial remodeling and atrial fibrillation (AF) susceptibility in spontaneously hypertensive rats (SHR). Methods Twenty-four 7-week-old male SHR were randomly divided into SHR group, SHR + Val group (30 mg · kg

Effect of high-intensity interval training on the skeletal muscle of spontaneously hypertensive rats

Abstract Aim: This study aimed to evaluate the effect of High-Intensity Interval Training (HIIT) on the skeletal muscle of Spontaneously Hypertensive Rats (SHR). Method: In total, 20 male rats, SHR, 12 months old, were used, distributed into 2 groups: Control Group (C) and Training Group (HIIT). The training lasted approximately 50 minutes/day, 5 days/week, for 8 weeks. Systolic blood pressure (BP) was measured at the beginning and end of the study. Analysis: The medial gastrocnemius muscle was used to measure the smallest fiber diameter, after which the Shapiro-Wilk normality test was performed, followed by the Mann Whitney test to compare the medians and interquartile intervals (IQI) of the muscle fibers and Student t-test for performance. For analysis of BP, Analysis of Variance - ANOVA was used, followed by Tukey's post-test. All procedures adopted a significance value of 5% (p < 0.05). Results: The median values for the variable "smallest diameter" of muscle fibers were 29.48 (IQI: 9.96) µm in the C group and 33.45 (IQI: 9.44) µm in the HIIT group (p < 0.05). Also, the performance was increased in the trained animal group and blood pressure values decreased significantly at the end of the experiment (p < 0.05). Conclusion: The HIIT intensity promoted an increase in the median values of the muscle fibers and performance. Finally, a significant decrease was observed in blood pressure variation values.

Tyrosine hydroxylase and ß2-adrenergic receptor expression in leukocytes of spontaneously hypertensive rats: putative peripheral markers of central sympathetic activity

The sympathetic nervous system (SNS) plays a fundamental role in the pathophysiology of cardiovascular diseases, including primary arterial hypertension. In this study, we aimed to investigate whether the expression of the rate-limiting enzyme in catecholamine synthesis, tyrosine hydroxylase (TH), and the β2-adrenergic receptor (β2-AR) in immune cells from peripheral blood, reflect central SNS activity in spontaneously hypertensive rats (SHR). TH expression in the lower brainstem and adrenal glands and β2-AR expression in the lower brainstem were analyzed by western blot analyses. In the leukocytes, TH and β2-AR expression was evaluated by flow cytometry before and after chronic treatment with the centrally-acting sympathoinhibitory drug clonidine. Western blot analyses showed increased TH and β2-AR expression in the lower brainstem and increased TH in adrenal glands from SHR compared to normotensive Wistar Kyoto rats (WKY). Lower brainstem from SHR treated with clonidine presented reduced TH and β2-AR levels, and adrenal glands had decreased TH expression compared to SHR treated with vehicle. Flow cytometry showed that the percentage of leukocytes that express β2-AR is higher in SHR than in WKY. However, the percentage of leukocytes that expressed TH was higher in WKY than in SHR. Moreover, chronic treatment with clonidine normalized the levels of TH and β2-AR in leukocytes from SHR to similar levels of those of WKY. Our study demonstrated that the percentage of leukocytes expressing TH and β2-AR was altered in arterial hypertension and can be modulated by central sympathetic inhibition with clonidine treatment.

Effects and mechanism of total phenols of Magnolia officinalis combined with Maijunan Tablets on blood pressure of spontaneous hypertensive rats / 中草药·英文版

Objective: Maijunan (MJA) Tablets is a protected variety of traditional Chinese medicine (TCM) consisted of Pueraria lobata, hydrochlorothiazide (HTCZ), Uncaria rhynchophylla (366:1:980) and excipient. In the present work, MJA was consisted of the total flavones of P. lobata, HCTZ and total alkaloids of U. rhynchophylla (40:11:75). The combination of MJA and the total phenols of Magnolia officinalis (M-MJA) was consisted of the total flavones of P. lobata, the total phenols of M. officinalis, HCTZ and the total alkaloids of U. rhynchophylla (40:40:11:75). The aim of this work was to examine the effect and mechanism of M-MJA on the blood pressure of spontaneous hypertensive rats (SHRs). Methods: Adult male SHRs were randomly divided into control group, MJA group (180 mg/kg·d), and the M-MJA group (218 mg/kg·d) (n = 5). SHRs were orally administered with M-MJA and MJA respectively once a day for 8 weeks, the blood pressure of SHRs was measured every two weeks, and the biochemical indicators related to blood pressures were detected at the last dosing. Results: After oral administration of M-MJA to SHRs once a day for 8 weeks, the systolic and diastolic blood pressures of SHRs were deceased significantly. M-MJA affected renin-angiotensin-aldosterone system by decreasing the levels of Ren, Ang II and ALD, affected the endothelial function by decreasing the levels of ET-1 and 20-HETE, and increasing the level of eNOS, affected the oxidative stress by increasing the protein expression of Nrf2 and the activities of HO-1 and GSH-Px, and decreasing the protein expression of CYP2E1 and CYP4A, as well as the content of MDA. Conclusion: These results indicated that M-MJA could regulate the renin-angiotensin-aldosterone system, improve endothelial function, and inhibit CYP4A activity to reduce the production of 20-HETE, alleviate the oxidative stress disorder of the visceral organs, and eventually exert antihypertensive effect. Additionally, the anti-oxidant ability, regulating the renin-angiotensin-aldosterone system and improving endothelial function of M-MJA are more powerful than that of MJA, suggesting that M-MJA may have a better anti-hypertensive effect than MJA.

Observation on the changes of cerebral venules wall matrix in spontaneous hypertensive rat with high-salt diet / 中国脑血管病杂志

Objective To investigate the changes of wall matrix of the cerebral venules in the high-salt fed spontaneously hypertensive (SHR) rats. Methods Six SI1R and six Wistar Kyoto (WKY) male rats at the age of 10 weeks were experimented. Rats in the SHR group were given high-salt diet ( 1% sodium chloride drinking water and 4% high-salt) for 10 months,and rats in the WKY group were given normal drinking water and fed for 10months,The rats were all raised in the Institute of Neurology,Huashan Hospital, Fudan University. The feeding conditions were kept at a constant temperature of 22-24 and constant humidity of 55 ±5% ,with artificial light and shade for 12 h each. Morphological changes of cerebral small vessels were observed by hcmatoxylin-eosin (HE) staining. Venules were differentiated from arterioles through the presence of ot-smooth muscle actin. Immunofluorescence was performed to observe the expression of collagen I (COL I ) .collagen IV ( COLIV) ,fibronectin (FN) and laminin (LN) in cerebral venules. The brain tissue was divided into cortex,deep gray matter and hippocampus regions. The collagen deposition and expression of related extracellular matrix of venules in these regions were compared. Results ( 1) HE staining showed vascular remodeling of arterioles in high-salt fed SHR, which was consistent with the pathological characteristics of arteriosclerotic cerebral small vessel disease. ( 2) Compared with the WKY group,the high-salt fed SHR group showed obviously increased cerebral venules COL I deposition and LN expression (153 ± 12 ts. 106 ±8,/=3. 253 =0. 004; 135 ±11 vs. 99 ±9,1 = 2. 575,/' =0. 017); COLIV deposition had an increasing trend,but without statistically significant difference (118 ± 12 vs. 99 ± 4,t = 1. 508,/' = 0. 142). There was no significant difference in FN expression ( 104 ±4 vs. 101 ±3,/= 0.664,P =0.512). (3) Compared with the group,the SHR group had significantly increased deposition of COLlin cortex and deep gray matter venules (159 ± 15 vs. 108 ±7,/=3.075,/'=0.007; 139 ± 12 i5.96±9,/= 2. 868, P =0. 009); No statistically significant difference was found bftween the two groups in hippocampus region ( 169 ± 16 133 ±9 ,i = 1. 926,P =0.072) ;No statistical significance was found between the high-salt diet SHR group and the WKY group in COLIV and fibronectin deposi.ion of venules in these regions (P > 0.05);Compared with the group,the L\ expression of deep gray matter venules in the SHR group after high-salt diet was significantly increased (125 ± 12 vs. TJ ±5,1 =3.767,/J = 0.002) ,and there was no statistically significant difference in both cortical and hippocampal regions (138 ±18 vs. 109 ±7,/= l.460,/>=0. 174; 153 ± 16 m. 133 ± 13,/= 0.960, P = 0. 359) . Conclusions Tic expression of COL I and LN of cerebral venules wall was increased in the high-salt fed SHR. The COL 1 deposition was most significant in cortex and deep gray matter,and the LN deposition was mainly in deep gray matter.

Effect of Mangiferin on Morphology of Relevant Vessels and MCP-1/CCR-2 Pathway in Spontaneously Hypertensive Rats / 中国实验方剂学杂志

Objective:To observe the morphological changes of carotid artery, thoracic aorta and superior mesenteric artery in spontaneously hypertensive rats(SHR), in order to further study the effect of Mangiferin on the expressions of inflammatory factors and monocyte chemoattract protein-1 (MCP-1)/c-chemokine receptor type 2 (CCR-2) pathway in SHR. Method:Forty spontaneously hypertensive rats were randomly divided into model group, benazepril group (10 mg·kg-1·d-1) and low, medium and high-dose mangiferin groups (25, 50, 100 mg·kg-1·d-1). Eight male WKY rats of the same age were selected as normal control group. Systolic blood pressure was observed every two weeks after eight weeks of administration. Morphology of carotid artery, thoracic aorta and superior mesenteric artery was observed by hematoxylin-eosin (HE) staining. Immunohistochemical assay (IHC) and Western blot were used to detect MCP-1 and CCR-2 protein expressions in thoracic aorta. MCP-1 and CCR-2 mRNA expression levels in thoracic aorta were detected by Real-time quantitative fluorescence PCR (Real-time PCR). Result:Compared with the normal group, the inflammatory cells in the model group increased significantly, the systolic blood pressure was significantly higher than that in the WKY group (PPPPConclusion:There are inflammation damages in carotid artery, thoracic aorta and superior mesenteric artery of spontaneously hypertensive rats. Mangiferin has an anti-inflammatory effect by possibly inhibiting the expressions of MCP-1/CCR-2 pathway in SHR vessels.

Effect of gemigliptin on cardiac ischemia/reperfusion and spontaneous hypertensive rat models

Diabetes is associated with an increased risk of cardiovascular complications. Dipeptidyl peptidase-4 (DPP-IV) inhibitors are used clinically to reduce high blood glucose levels as an antidiabetic agent. However, the effect of the DPP-IV inhibitor gemigliptin on ischemia/reperfusion (I/R)-induced myocardial injury and hypertension is unknown. In this study, we assessed the effects and mechanisms of gemigliptin in rat models of myocardial I/R injury and spontaneous hypertension. Gemigliptin (20 and 100 mg/kg/d) or vehicle was administered intragastrically to Sprague-Dawley rats for 4 weeks before induction of I/R injury. Gemigliptin exerted a preventive effect on I/R injury by improving hemodynamic function and reducing infarct size compared to the vehicle control group. Moreover, administration of gemigliptin (0.03% and 0.15%) powder in food for 4 weeks reversed hypertrophy and improved diastolic function in spontaneously hypertensive rats. We report here a novel effect of the gemigliptin on I/R injury and hypertension.

The relationship between left ventricular myocardial strain and different stages of cardiac dysfunction in spontaneously hypertensive rats evaluated by two‐dimensional strain echocardiography / 中华超声影像学杂志

Objective To investigate the relationship between multi‐dimensional myocardial strain and global cardiac function in different stages of cardiac dysfunction in spontaneously hypertensive rats ( SHR ) by two‐dimensional strain echocardiography . MethodsAccording to cardiac function measurements ,SHR of 28 to 102 weeks were divided into 3 groups :Normal group[ Group A , normal left ventricular ejection fraction( LVEF) and left ventricular end‐diastolic pressure( LVEDP) , n ＝13] ,diastolic dysfunction group ( Group B , normal LVEF but increased LVEDP , n ＝24) ,and systolic dysfunction group ( Group C ,decreased LVEF and increased LVEDP , n ＝ 17 ) ,with WKY rats at similar weeks of age as controls ( group a , n ＝ 7 ;group b , n ＝ 12 ; and group c , n ＝ 16 ) . Morphological parameters of left ventricular were measured by echocardiography . Using EchoPac workstation ,systolic peak longitudinal strain ,circumferential and radial strain were calculated at the left ventricular middle levels . Extracellular collagen content was observed histologically . Results Left atrial dimension increased in group B and larger in group C ,and dilated left ventricular and thickened wall were only found in group C .Systolic peak longitudinal strain of group B was significantly lower than group A and group a ( all P ＜ 0 .05 ) ,and deteriorated in group C( P ＜ 0 .05 ) ,while systolic peak circumferential and radial strain and LVEF were only significantly decreased in group C ( all P＜ 0 .05 ) ,w hile there was no significant difference between Group A and Group B( all P ＞0 .05) . Collagen content in endocardial and mid‐layer myocardium increased in group B and C , and increased epicardial collagen occurred in group C . Systolic peak longitudinal strain , circumferential and radial strain were correlated positively with LVEF( r ＝0 .65 ,0 .80 ,0 .80 ,all P ＜0 .01) . Conclusions In SHR ,systolic peak longitudinal strain obtained by echocardiography is decreased in the period of diastolic dysfunction ,w hile the damage of systolic peak circumferential and radial strain leads to the systolic dysfunction .

Effect of alpha-lipoic acid supplementation on blood pressure, renal oxidant-antioxidant status and renal damage in spontaneously hypertensive rats

Objective: To investigate the effect of alpha-lipoic acid (ALA) supplementation on systolic blood pressure (SBP), renal oxidant-antioxidant status and renal damage in spontaneously hypertensive rats (SHR) and SHR administered with Nω-nitro-L-arginine methyl ester (L-NAME). Methods: Male rats were divided into four groups (SHR, SHR+ALA, SHR+L-NAME, SHR+ALA+L-NAME). The respective group of rats was administered with ALA (100 mg/kg/day) from age 4 weeks to 28 weeks and L-NAME (25 mg/kg/day) from age 16 weeks to 28 weeks. SBP was measured every two weeks and twenty four hour urine was collected at 4 weeks, 16 weeks and 28 weeks for estimation of protein, creatinine and N-acetyl-β-D-glucosaminidase. At the end of 28 weeks, rats were sacrificed and blood and kidneys collected for assessment of blood creatinine, kidney thiobarbituric acid reactive substances, protein carbonyls, superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione S-transferase, glutathione disulfide, glutathione, total antioxidant status and nitric oxide as well as histopathological examination. Results: ALA supplementation significantly reduced SBP of SHR and SHR+L-NAME rats when compared to their respective non-supplemented groups. Renal oxidant status markers including thiobarbituric acid reactive substances and protein carbonyls were significantly reduced on SHR and SHR+L-NAME rats supplemented with ALA at 28 weeks as well as ALA supplementation significantly increased renal antioxidants including superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase, glutathione and glutathione/glutathione disulfide ratio at 28 weeks. No significant change in nitric oxide levels was observed between the ALA supplemented and non-supplemented groups. Renal dysfunction was ameliorated on ALA supplementation as evidenced by significant reduction in urine protein levels, N-acetyl-β-D-glucosaminidase activity and significant increase of creatinine clearance in SHR and SHR+L-NAME at 28 weeks. Renal histopathological examination showed that ALA supplementation prevented vascular damage in SHR and ameliorated glomerular damage in SHR+L-NAME at 28 weeks. Conclusions: ALA has hypotensive and renoprotective effects on both SHR and SHR+L-NAME, which could be due to its ability to ameliorate oxidative stress in the kidneys.

Changes of Bax, Bcl-2, CCR-2, MCP-1, and TGF-β1 genes in the left ventricle of spontaneously hypertensive rat after losartan treatment / 소아과

PURPOSE: Increased apoptosis was recently found in the hypertrophied left ventricle of spontaneously hypertensive rats (SHRs). Although the available evidence suggests that apoptosis can be induced in cardiac cells by various insults including pressure overload, cardiac apoptosis appears to result from an exaggerated local production of angiotensin in adult SHRs. Altered expressions of Bcl associated X (Bax), Bcl-2, chemokine receptor (CCR)-2, monocyte chemoattractant protein (MCP)-1, transforming growth factor (TGF)-β1, phosphorylated extracellular signal-regulated kinases (PERK), and connexin 43 proteins, and kallikrein mRNA were investigated to explore the effects of losartan on the SHR model. METHODS: Twelve-week-old male rats were grouped as follows: control (C), SHR (hypertension: H), and losartan (L; SHRs were treated with losartan [10 mg/kg/day] for 5 weeks). Western blot and reverse transcription polymerase chain reaction assays were performed. RESULTS: Expression of Bax, CCR-2, MCP-1, TGF-β1, PERK, and connexin 43 proteins, and kallikrein mRNA was significantly increased in the H group compared to that in the C group at weeks 3 and 5. Expression of Bax, CCR-2, MCP-1, TGF-β1, and connexin 43 proteins and kallikrein mRNA was significantly decreased after losartan treatment at week 5. PERK protein expression was significantly decreased after losartan treatment at weeks 3 and 5. Bcl-2 protein expression was significantly decreased in the H group compared to that in the C group at weeks 3 and 5. CONCLUSION: Losartan treatment reduced expression of Bax, CCR-2, MCP-1, TGF-β1, PERK, and connexin 43 proteins, and kallikrein mRNA in SHRs, along with decreased inflammation and apoptosis.

Icariside II improves left ventricular function by improving endoplasmic reticulum stress and caspase 12 signaling in SHR / 中国药理学通报

Aim: To explore the mechanism of icariside II (ICS II) on improving left ventricular function based on endoplasmic reticulum stress and caspase-12 signaling in spontaneously hypertensive rats (SHRs). Methods: Thirty 14-week-old male SHRs were divided into model group, ICS II low, middle and high dose groups and positive drug group (n = 6). WKY was used as control group (n =6). ICS II groups were respectively given ICS 114, 8, 16 mg · kg-1(ig, qd), and positive drug group was given losartan (20 mg · kg-1). At the end of 26th weeks, anesthetized rats were measured by ultrasound for detection of the left ventricular function, RT-PCR was used to determine the level of GRP78 mR- NA in the left ventricle tissue, and Western blot was used to assess the levels of GRP78 and cleaved-caspase- 12/9/3 protein in the left ventricle tissues. Results: Compared with WKY group, the internal diameter and posterior wall thickness of the left ventricular end diastolic increased, while the ejection fraction and fractional shortening decreased in SHR group. GRP78 mRNA and protein levels were up-regulated, and the levels of cleaved-caspase-12/9/3 protein were raised in left ventricle (P < 0.05). Compared with SHR group, the internal diameter and posterior wall thickness of the left ventricular end diastolic increased in ICS II medium and high dose groups and positive drug group (P <0. 05), while the ejection fraction and fractional shortening decreased (P<0.05). GRP78 mRNA and protein levels were down-regulated, the levels of cleaved-caspase-12/ 9/3 protein declined in left ventricle (P <0.05). Conclusions: ICS II could improve left ventricular function in SHRs, and its mechanism may be related to improving left ventricular endoplasmic reticulum stress and down-regulating the elevated caspase-12 signaling.

Effect of Lumbricus Peptides on TLR4/NF-<i>κ</i>B Signaling Pathway in Spontaneous Hypertensive Rat Kidney / 中国实验方剂学杂志

@# <b>Objective:</b>to observe the effect and mechanism of lumbricus peptides on early renal injury in spontaneous hypertensive rats (SHR) based on Toll-like receptors 4 (TLR4)/nuclear factor-<i>κ</i>B(NF-<i>κ</i>B) signaling pathway. <b>Method:</b>The 40 SHRs were randomly divided into model group (equal volume of distilled water by intragastric administration), lumbricus peptides low, middle and high dose groups (126, 252, 504 mg·kg^-1), and Benazepril group (0.9 mg·kg^-1), <i>n</i>=8 in each group. 8 male rats with normal blood pressure at the same age were set as the normal control group,with equal volume of distilled water. After treatment for 60 consecutive days, enzyme-linked immunosorbent assay (ELISA) was used to determine microalbumin (mAlb)and <i>N</i>-acetyl-<i>β</i>-<i>D</i>-glucosaminidase (NAG) content in 24 h urine as well as the level of serum angiotensinⅡ (AngⅡ). Ultrastructural changes of rat kidneys were observed by transmission electron microscope. Western blot was used to detect renal TLR4, NF-<i>κ</i>B p65 protein levels. Immunohistochemical method was used to detect renal tumor necrosis factor-<i>α</i> (TNF-<i>α</i>) and interleukin 10 (IL-10) expression. <b>Result:</b>As compared with the normal control group, the levels of urine mAlb, NAG and serum Ang Ⅱ were increased in the model group (<i>P</i><0.05); the expression of TLR4 and NF-<i>κ</i>B p65 protein was increased (<i>P</i><0.05); expression of TNF-<i>α</i> was increased (<i>P</i><0.05), while IL-10 expression was decreased (<i>P</i><0.05). Transmission electron microscopy of kidney tissues showed that most of the glomeruli of the model group had podocyte foot process fusion, mesangial cells and mesangial matrix hyperplasia. As compared with the model group, the levels of urine mAlb, NAG, and serum Ang Ⅱ were decreased in the rats in lumbricus peptides groups and benazepril group (<i>P</i><0.05); the expression of TLR4 and NF-<i>κ</i>B p65 protein was decreased (<i>P</i><0.05); the positive expression of TNF-<i>α</i> in kidney was decreased to different extent (<i>P</i><0.05), but the expression of IL-10 was increased (<i>P</i><0.05). Transmission electron microscopy of kidney tissues showed that the damage of kidneys in rats after administration of high-dose lumbricus peptides and benazepril was improved in varying degrees. <b>Conclusion:</b>lumbricus peptides can reduce early renal damage in SHRs, and its mechanism may be achieved by regulating the AngⅡ-TLR4/NF-<i>κ</i>B pathway.

The relationship between left ventricular myocardial strain and different stages of cardiac dysfunction in spontaneously hypertensive rats evaluated by two-dimensional strain echocardiography / 中华超声影像学杂志

Objective@#To investigate the relationship between multi-dimensional myocardial strain and global cardiac function in different stages of cardiac dysfunction in spontaneously hypertensive rats (SHR) by two-dimensional strain echocardiography.@*Methods@#According to cardiac function measurements, SHR of 28 to 102 weeks were divided into 3 groups: Normal group[Group A, normal left ventricular ejection fraction(LVEF) and left ventricular end-diastolic pressure(LVEDP), n=13], diastolic dysfunction group (Group B, normal LVEF but increased LVEDP, n=24), and systolic dysfunction group (Group C, decreased LVEF and increased LVEDP, n=17), with WKY rats at similar weeks of age as controls (group a, n=7; group b, n=12; and group c, n=16). Morphological parameters of left ventricular were measured by echocardiography. Using EchoPac workstation, systolic peak longitudinal strain, circumferential and radial strain were calculated at the left ventricular middle levels. Extracellular collagen content was observed histologically.@*Results@#Left atrial dimension increased in group B and larger in group C, and dilated left ventricular and thickened wall were only found in group C. Systolic peak longitudinal strain of group B was significantly lower than group A and group a(all P<0.05), and deteriorated in group C(P<0.05), while systolic peak circumferential and radial strain and LVEF were only significantly decreased in group C (all P<0.05), while there was no significant difference between Group A and Group B(all P>0.05). Collagen content in endocardial and mid-layer myocardium increased in group B and C, and increased epicardial collagen occurred in group C. Systolic peak longitudinal strain, circumferential and radial strain were correlated positively with LVEF(r=0.65, 0.80, 0.80, all P<0.01).@*Conclusions@#In SHR, systolic peak longitudinal strain obtained by echocardiography is decreased in the period of diastolic dysfunction, while the damage of systolic peak circumferential and radial strain leads to the systolic dysfunction.

Losartan improves alveolar bone dynamics in normotensive rats but not in hypertensive rats

Abstract Hypertension is one of the main causes of premature death in the world; also, it is associated with several bone alterations. Preclinical studies have demonstrated delayed alveolar bone healing in hypertensive rats. However, losartan has been favorable for consolidation of bone grafts and reduction in active periodontitis. Therefore, losartan is suggested to be effective in bone formation stages, as well as in the synthesis of matrix proteins and mineralization. Objectives: To evaluate the alveolar bone dynamics in hypertensive rats treated with losartan by laser confocal microscopy and histological analysis. Methodology: Thirty-two rats, 16 spontaneously hypertensive rats (SHR) and 16 Wistar albinus rats, treated or not with losartan (30 mg/kg/day) were used. Calcein fluorochrome at 21 days and alizarin red fluorochrome at 49 days were injected in rats (both 20 mg/kg). The animals were submitted to euthanasia 67 days after treatment, and then the right maxilla was removed for laser confocal microscopy analysis and the left maxilla for histological analysis. Results: This study showed a greater calcium marking in normotensive animals treated with losartan in relation to the other groups. Laser confocal microscopy parameters showed higher values of bone volume formed, mineralized surface, active surface of mineralization and bone formation rate in normotensive animals treated with losartan. However, a smaller mineralized surface was observed in all hypertensive animals. Conclusion: Losartan can improve bone mineralization parameters under normal physiological conditions, but the same anabolic effect does not occur under hypertension.

Effect of alpha-lipoic acid supplementation on blood pressure, renal oxidant-antioxidant status and renal damage in spontaneously hypertensive rats

Objective: To investigate the effect of alpha-lipoic acid (ALA) supplementation on systolic blood pressure (SBP), renal oxidant-antioxidant status and renal damage in spontaneously hypertensive rats (SHR) and SHR administered with N