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.
Rats ; Male ; Animals ; Rats, Inbred SHR ; AMP-Activated Protein Kinases/metabolism* ; bcl-2-Associated X Protein/metabolism* ; Aorta, Thoracic ; Beclin-1 ; Hot Temperature ; TOR Serine-Threonine Kinases/metabolism* ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Apoptosis ; Aortic Diseases ; Autophagy ; Autophagy-Related Protein-1 Homolog/metabolism*

OBJECTIVE: To explore the effect of Kuanxiong Aerosol (KXA) on isoproterenol (ISO)-induced myocardial injury in rat models. METHODS: Totally 24 rats were radomly divided into control, ISO, KXA low-dose and high-dose groups according to the randomized block design method, and were administered by intragastric administration for 10 consecutive days, and on the 9th and 10th days, rats were injected with ISO for 2 consecutive days to construct an acute myocardial ischemia model to evaluate the improvement of myocardial ischemia by KXA. In addition, the diastolic effect of KXA on rat thoracic aorta and its regulation of ion channels were tested by in vitro vascular tension test. The influence of KXA on the expression of calcium-CaM-dependent protein kinase II (CaMK II)/extracellular regulated protein kinases (ERK) signaling pathway has also been tested. RESULTS: KXA significantly reduced the ISO-induced increase in ST-segment, interventricular septal thickness, cardiac mass index and cardiac tissue pathological changes in rats. Moreover, the relaxation of isolated thoracic arterial rings that had been precontracted using norepinephrine (NE) or potassium chloride (KCl) was increased after KXA treatment in an endothelium-independent manner, and was attenuated by preincubation with verapamil, but not with tetraethylammonium chloride, 4-aminopyridine, glibenclamide, or barium chloride. KXA pretreatment attenuated vasoconstriction induced by CaCl₂ in Ca²⁺-free solutions containing K⁺ or NE. In addition, KXA pretreatment inhibited accumulation of Ca²⁺ in A7r5 cells mediated by KCl and NE and significantly decreased p-CaMK II and p-ERK levels. CONCLUSION KXA may inhibit influx and release of calcium and activate the CaMK II/ERK signaling pathway to produce vasodilatory effects, thereby improving myocardial injury.
Aerosols ; Animals ; Aorta, Thoracic ; Calcium/metabolism* ; Endothelium, Vascular/metabolism* ; Myocardial Ischemia/metabolism* ; Rats ; Vasodilation

Objective: To investigate the expression pattern of tropomyosin 2(TPM2) in aorta of patients with aortic dissection and explore its clinical implication. Methods: Thirteen cases with acute type A aortic dissection(TAAD) diagnosed by transabdominal aortic angiography from 2015 in Tongji Hospital were included. During the operation, the aortic wall tissues of these patients were collected. Ten patients with heart transplantation were selected as control group, and normal aortic wall tissues were taken. The hematoxylin-eosin (HE) and Verhoeff's Van Gieson (EVG) staining were performed to observe the morphological changes of aorta. The mRNA expression level of TPM2 was measured by real-time fluorescent quantitative-PCR, and the protein levels of TPM2 were detected by Western blot and immunohistochemical staining. Image The J software was used to collect the optical density values of each point on the image, obtain the integrated optical density(IOD) value, and calculate the average density(%, IOD/area of the target distribution area). Results: HE and EVG staining revealed medial degeneration and broken elastic fiber in aorta of TAAD patients. The mRNA expression levels of TPM2 were significantly upregulated in aorta of TAAD patients as compared to the control group (P<0.05), so as the TPM2 protein expression levels ((9.73±1.20)% vs. (0.11±0.04)%, P<0.05). And TPM2 was mainly expressed in cytoplasm. Conclusion: The increased expression of TPM2 in TAAD patients hints that TPM2 might be involved in the pathogenesis of aortic dissection.
Aneurysm, Dissecting/genetics* ; Aorta ; Aortic Aneurysm, Thoracic/genetics* ; Gene Expression ; Humans ; RNA, Messenger ; Tropomyosin/metabolism*

OBJECTIVES: To investigate the effects of Astragaloside IV (AST) on diastolic function of rat thoracic aorta rings which was injured by microvesicles derived from hypoxia/reoxygenation (H/R)-treated human umbilical vein endothelial cells (HUVECs), and the mechanism of AST. METHODS: H/R-induced endothelial microvesicles (H/R-EMVs) were generated from cultured HUVECs under the condition of hypoxia for 12 hour/Reoxygenation for 4 hour, H/R-EMVs were stored in D-Hank's solution. Male Wistar rats were underwent thoracotomy, the thoracic aorta with intact endothelium were carefully removed and cut into 3~4 mm rings. The experiment was divided into six groups. H/R-EMVs group:thoracic aortic rings of rats were incubated in culture medium and treated with H/R-EMVs in a final concentration of 10g/ml; different doses of AST groups:thoracic aortic rings of rats were treated with 10, 20, 40, 60 mg/L AST co-incubated with 10g/ml H/R-EMVs respectively; control group were treated with the same volume of D-Hank's solution. Duration of incubation was 4 h, each group was tested in five replicate aortic rings. Effects of AST on endothelium-dependent relaxation were detected. The production of nitric oxide (NO) and the level of endothelial NO synthase (eNOS), phosphorylated eNOS (p-eNOS, Ser-1177), serine/threonine kinase (Akt), phosphorylated Akt (p-Akt, Ser-473), extracellular regulated protein kinases (ERK1/2) and phosphorylated ERK1/2 (p-ERK1/2, Thr202/Tyr204) of rat thoracic aortic rings were detected. RESULTS: Teng/ml H/R-EMVs could impaire the relaxation of rat thoracic aortic rings significantly (<0.01). Compared with H/R-EMVs group, relaxation of rat thoracic aortic rings was increased by 20, 40 and 60 mg/L AST in a concentration-dependent manner (<0.01), the level of NO production was also enhanced (<0.05, <0.01). The level of t-eNOS, t-Akt and ERK1/2 was not changed, but the level of p-eNOS, p-Akt and p-ERK1/2 increased by the treatment with AST (<0.01). CONCLUSIONS AST could effectively ameliorate endotheliumdependent relaxation of rat thoracic aortic rings impaired by H/R-EMVs in a concentration-dependent manner, the mechanism might involve the increase in production of NO, and the protein level of p-eNOS, p-Akt and p-ERK1/2.
Animals ; Aorta, Thoracic ; drug effects ; Cell-Derived Microparticles ; pathology ; Human Umbilical Vein Endothelial Cells ; Humans ; In Vitro Techniques ; MAP Kinase Signaling System ; Male ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type III ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Rats ; Rats, Wistar ; Saponins ; pharmacology ; Triterpenes ; pharmacology ; Vasodilation

OBJECTIVETo study the effect of gastrodin on isolated thoracic aorta rings of rats and to investigate the potential mechanism.

METHODSA perfusion model of isolated thoracic aorta rings of rats was applied. The effect of cumulative gastrodin (5, 50, 100,150, 200, and 250 μmol/L) on endothelium-intact aorta rings was investigated. The same procedure was applied to observe the effect of gastrodin on endothelium-intact/denuded aorta rings pre-contracted with 10(-6) mol/L phenylephrine hydrochloride (PE). The aorta rings incubated by 200 mmol/L gastrodin in the Ca(2+)-free (K-H) solution was contracted by using PE. The effect of 200 mmol/L gastrodin on endothelium-denuded aorta rings pre-contracted with 60 mmol/L KCl was also observed.

RESULTSCompared with the denuded gastrodin group, the intact gastrodin group could significantly relax the PE-contracted aorta rings (P<0.01). In Ca(2+)-free (K-H) solution KHS, the PE-induced contraction rate of aorta rings pre-incubated by gastrodin was 6.5%±0.7%, which was significantly less than the control group (11.8%±0.9%,P<0.01). However, after 3 mmol/L CaCl2 was added, the Ca(2+)-induced contraction in the gastrodin group (51.7%±2.4%) was similar to that in the control group (49.8%±2.8%). The contractile rate of rings in the KCl-contracted gastrodin group (96.3%±0.6%) was not significantly different from that in the control group (96.8%±1.2%).

CONCLUSIONSGastrodin has the effect of vasorelaxation on isolated thoracic aorta rings of rats. The mechanism of the vasorelaxation of gastrodin may mainly work through the inhibition of inositol 1, 4, 5-trisphosphosphate receptor on the sarcoplasmic reticulum of the arterial smooth muscle, which leads to the reduction of the Ca(2+) released from the sarcoplasmic reticulum.

Animals ; Aorta, Thoracic ; drug effects ; physiology ; Benzyl Alcohols ; pharmacology ; Calcium ; metabolism ; Endothelium, Vascular ; physiology ; Female ; Glucosides ; pharmacology ; In Vitro Techniques ; Male ; Phenylephrine ; pharmacology ; Rats ; Rats, Wistar ; Vasodilation ; drug effects

OBJECTIVETo investigate the effects and mechanisms of high glucose on the phenotype transformation of rat vascular smooth muscle cells (VSMCs).

METHODSVSMCs ere isolated from rat thoracic aorta and the 3rd-5th VSMCs were incubated with normal glucose (5.5 mmol/L), high glucose (25 mmol/L), or high glucose (25 mmol/L) + P38 inhibitor (25 mmol/L +SB203580) for another 24 hours. Then the gene expression of osteopontin (OPN), alpha smooth-actin (alpha-SMA), matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9(MMP-9) were assayed by real time RT-PCR, the protein expression of P38 were assayed by Western blot.

RESULTS(1) High glucose promoted the phenotype transformation of VSMCs and up-regulated the expression of MMP-2 and MMP-9. (2) High glucose promoted the phosphorylation of P38. (3) SB203580, the inhibitor of P38/MAPK signal pathway, inhibited the effects of high glucose on phenotype transformation and expression of MMP-2 and MMP-9.

CONCLUSIONHigh glucose may promote phenotype transformation of VSMCs via the signal pathway of P38/MAPK.

Actins ; metabolism ; Animals ; Aorta, Thoracic ; cytology ; Blotting, Western ; Cells, Cultured ; Glucose ; pharmacology ; Imidazoles ; pharmacology ; MAP Kinase Signaling System ; Matrix Metalloproteinase 2 ; Matrix Metalloproteinase 9 ; metabolism ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; cytology ; drug effects ; Osteopontin ; metabolism ; Phenotype ; Pyridines ; pharmacology ; Rats ; p38 Mitogen-Activated Protein Kinases ; metabolism

OBJECTIVETo explore the effect of ouabain on intracellular Ca(2+) concentration ([Ca(2+)]i) in thoracic aorta vascular smooth muscle cells (VSMCs) in vitro.

METHODSPrimary SD rat thoracic aorta VSMCs were cultured by tissue adherent method and identified by immunochemistry. The binding ability between ouabain and VSMCs was detected by autoradiography, and fluo 3-AM (a Ca(2+) fluorescent probe) was employed to investigate whether ouabain affected VSMCs within a short period of time. The effect of a truncated fragment of the sodium pump α2 subunit was assayed in antagonizing the effect of ouabain on [Ca(2+)]i in the VSMCs.

RESULTSWithin the concentration range of 0.1-100 nmol/L, ouabain was found to dose-dependently bind to the VSMCs. Different concentrations of ouabain (0-3200 nmol/L) caused a transient, dose-dependent increase in [Ca(2+)]i in the VSMCs, which was antagonized by the application of the truncated fragment of sodium pump α2 subunit.

CONCLUSIONSElevations in [Ca(2+)]i in the VSMCs can be the cytological basis of high ouabain-induced hypertension. The truncated fragment of the sodium pump α2 subunit can antagonize ouabain-induced increase of [Ca(2+)]i in the VSMCs, which provides a clue for understanding the pathogenesis of and devising a therapeutic strategy for high ouabain-induced hypertension.

Animals ; Aorta, Thoracic ; cytology ; Calcium ; metabolism ; Cells, Cultured ; Cytoplasm ; metabolism ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; drug effects ; metabolism ; Ouabain ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Sodium-Potassium-Exchanging ATPase

OBJECTIVECrassostrea gigas oyster extract has been reported to have antioxidant, antihypertensive and lipid-lowering properties that may be useful for treating cardiovascular diseases. This study aimed to evaluate the effect of C. gigas oyster extract on cardiovascular function in tissues from healthy rats.

METHODSSingle-cell microelectrode and isolated thoracic aortic organ bath studies were performed on tissues from 8-week-old healthy Wistar rats, using varying concentrations of C. gigas oyster extract. To elucidate a mechanism of action for the oyster's vasoactive properties, concentration response curves were carried out in the presence of a calcium channel inhibitior (verapamil), a nitric oxide synthase inhibitor (N(G)-nitro-L-arginine methyl ester), a potassium channel inhibitor (4-aminopyridine), in addition to the α-adrenoceptor inhibitor prazosin.

RESULTSOyster solution at 7 500 mg/mL inhibited noradrenaline-induced contraction in isolated aortic rings. Cardiac electrophysiology results showed that neither concentration of oyster solution was able to significantly reduce action potential duration at all phases of repolarisation in left ventricular papillary muscles from healthy animals.

CONCLUSIONWhen administered to healthy vascular tissue, C. gigas oyster extract inhibits contraction induced by noradrenaline. This effect is likely to be mediated through α-adrenoceptor inhibition, and to a lesser extent, calcium modulating activity.

Action Potentials ; drug effects ; Adrenergic alpha-Antagonists ; pharmacology ; Animals ; Aorta, Thoracic ; drug effects ; physiology ; Calcium ; metabolism ; Crassostrea ; Heart ; drug effects ; physiology ; Male ; Norepinephrine ; antagonists & inhibitors ; pharmacology ; Rats ; Rats, Wistar ; Vasoconstriction ; drug effects

BACKGROUNDBariatric surgery offers a productive resolution of type 2 diabetes mellitus (T2DM). The development of T2DM vasculopathy is due to chronic inflammation, which increases matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) expression. This study sought to examine MMP-9 and TIMP-1 expression in the thoracic aorta after duodenal-jejunal bypass (DJB) surgery on a T2DM rat model induced by a high-fat diet and low dose streptozotocin (STZ).

METHODSTwenty-one T2DM Wistar rats induced by high-fat diet and low dose STZ were randomly divided into DJB and sham duodenal-jejunal bypass (S-DJB) groups. Ten Wistar rats were fed a normal diet as a control. Recovery of gastrointestinal function post-operation and resumption of a normal diet completed the experiment. Body weight, blood glucose, blood lipid levels, and MMP-9 and TIMP-1 expression levels in aortic endothelial cells were measured throughout.

RESULTSDJB rats showed significant weight loss 2 weeks post-operation compared with S-DJB rats. After surgery, DJB rats showed significant improvement and steady glycemic control with improved insulin sensitivity and glucose tolerance. They also exhibited improved lipid metabolism with a decrease in fasting free fatty acids (FFAs) and triglycerides (all P < 0.05). Immunohistochemistry showed decreased MMP-9 and TIMP-1 expression 12 weeks after surgery (P < 0.01).

CONCLUSIONSDJB surgery on an induced T2DM rat model improves blood glucose levels and lipids, following a high-fat diet and low dose STZ treatment. In addition, DJB decreased MMP-9 and TIMP-1 expression in vascular endothelial cells, which may play an important role in delaying the development of T2DM vascular disease.

Animals ; Aorta, Thoracic ; metabolism ; Bariatric Surgery ; Body Weight ; physiology ; Diabetes Mellitus, Type 2 ; enzymology ; Male ; Matrix Metalloproteinase 1 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Rats

OBJECTIVETo investigate the effects of microvesicles (MVs) derived from hypoxia/reoxygenation (H/R)-treated human umbilical vein endothelial cells (HUVECs) on endothelium-dependent relaxation of rat thoracic aortic rings.

METHODSH/R injury model was established to induce HUVECs to release H/R-EMVs. H/R-EMVs from HUVECs were isolated by ultracentrifugation from the conditioned culture medium. H/R-EMVs were characterized using 1 μm latex beads and anti-PE-CD144 by flow cytometry. Thoracic aortic rings of rats were incubated with 2.5, 5, 10, 20 μg/ml H/R-EMVs derived from H/R-treated HUVECs for 4 hours, and their endothelium-dependent relaxation in response to acetylcholine (ACh) or endothelium-independent relaxation in response to sodium nitroprusside (SNP) was recorded in vitro. The nitric oxide (NO) production of ACh-treated thoracic aortic rings of rats was measured using Griess reagent. The expression of endothelial NO synthase (eNOS) and phosphorylated eNOS (p-eNOS, Ser-1177) in the thoracic aortic rings of rats was detected by Western blotting. Furthermore, the levels of SOD and MDA in H/R-EMVs-treated thoracic aortic rings of rats were measured using SOD and MDA kit.

RESULTSH/R-EMVs were induced by H/R-treated HUVECs and isolated by ultracentrifugation. The membrane vesicles (< 1 μm) induced by H/R were CD144 positive. ACh-induced relaxation and NO production of rat thoracic aortic rings were impaired by H/R-EMVs treatment in a concentration-dependent manner (P < 0.05, P < 0.01). The expression of total eNOS (t-eNOS) was not affected by H/R-EMVs. However, the expression of p-eNOS decreased after treated with H/R-EMVs. The activity of SOD decreased and the level of MDA increased in H/R-EMVs treated rat thoracic aortic rings (P < 0.01).

CONCLUSIONACh induced endothelium-dependent relaxation of thoracic aortic rings of rats was impaired by H/R-EMVs in a concentration-dependent manner. The mechanisms included a decrease in NO production, p-eNOS expression and an increase in oxidative stress.

Acetylcholine ; pharmacology ; Animals ; Aorta, Thoracic ; physiology ; Cell Hypoxia ; Endothelium, Vascular ; physiology ; Human Umbilical Vein Endothelial Cells ; cytology ; Humans ; In Vitro Techniques ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type III ; metabolism ; Nitroprusside ; pharmacology ; Oxidative Stress ; Rats