OBJECTIVETo explore the impact of sulfur dioxide (SO(2)) on hydrogen sulfide (H(2)S)/cystathionine-γ-lyase (CSE) and H(2)S/mercaptopyruvate sulfurtransferase (MPST) pathways in the pathogenesis of hypoxic pulmonary hypertension.

METHODSThirty-two male Wistar rats were randomly divided into four groups: control group (n = 8), hypoxic group (n = 8), hypoxic + SO(2) group (n = 8) and hypoxic + hydroxamate (HDX) group (n = 8). After 21 days of experiment, the concentration and production of H(2)S in lung tissues were measured respectively for each rat. The protein expression of CSE and MPST in intima and media of small pulmonary arteries in rats was detected with immunohistochemical method.

RESULTSCompared with control group, the mean pulmonary artery pressure (mPAP) in rats of hypoxic group was increased significantly [(33.38 ± 6.32) mm Hg vs. (16.74 ± 3.81) mm Hg, P < 0.01]. Compared with hypoxic group, the mPAP in rats of hypoxic + SO(2) group was decreased significantly [(29.65 ± 2.53) mm Hg vs. (33.38 ± 6.32) mm Hg, P < 0.01]. However, compared with hypoxic group, the mPAP in rats of hypoxic + HDX group was increased significantly [(39.44 ± 6.26) mm Hg vs. (33.38 ± 6.32) mm Hg, P < 0.01]. Compared with control group, the concentration [(2.02 ± 0.43) µmol/g vs. (3.11 ± 0.42) µmol/g, P < 0.01] and production [(19.64 ± 3.48) nmol/(g·min)vs. (28.20 ± 5.95) nmol/(g·min), P < 0.05] of H(2)S were decreased significantly in rats of hypoxic group, respectively. When treated with SO(2), hypoxic rats showed an increased concentration [(2.73 ± 0.20) µmol/g vs. (2.02 ± 0.43) µmol/g, P < 0.01] and production [(26.24 ± 1.92) nmol/(g·min) vs. (19.64 ± 3.48) nmol/(g·min), P < 0.01] of H(2)S in lung tissue compared with those without receiving SO(2) treatment. When treated with HDX, hypoxic rats showed a significant decrease in concentration [(1.64 ± 0.23) µmol/g vs. (2.02 ± 0.43) µmol/g, P < 0.05] and production [(13.94 ± 3.63) nmol/(g·min) vs. (19.64 ± 3.48) nmol/(g·min), P < 0.05] of H(2)S in lung tissue compared with those without receiving HDX treatment. As for the expression of CSE in small pulmonary arteries (SPAs), compared with control group, the expression of CSE in intima [(0.31 ± 0.02) vs. (0.36 ± 0.01), P < 0.01] and media [(0.27 ± 0.01) vs. (0.30 ± 0.01), P < 0.01] in rats of hypoxic group was decreased significantly. While compared with hypoxic group, the expression of CSE in intima [(0.35 ± 0.02) vs. (0.31 ± 0.02), P < 0.01] in SPAs of hypoxic + SO(2) group was increased significantly. With HDX treatment, the expression of CSE in intima [(0.26 ± 0.01) vs. (0.31 ± 0.02), P < 0.01] in SPAs of hypoxic group was lower than that without HDX treatment. As for the expression of MPST in SPAs, compared with hypoxic group, the expression of MPST in media [(0.32 ± 0.02) vs. (0.29 ± 0.01), P < 0.01] in SPAs of hypoxic + SO(2) group was increased significantly.

CONCLUSIONSO(2) might upregulate H(2)S/CSE and H(2)S/MPST pathways in pulmonary arteries of hypoxic rats.

Animals ; Cystathionine gamma-Lyase ; metabolism ; Hydrogen Sulfide ; metabolism ; Hypertension, Pulmonary ; enzymology ; physiopathology ; Hypoxia ; metabolism ; physiopathology ; Male ; Pulmonary Artery ; metabolism ; physiopathology ; Rats ; Rats, Wistar ; Sulfur Dioxide ; pharmacology ; Sulfurtransferases ; metabolism

Experiments were performed in male Sprague-Dawley rats (150-200 g). A silver clip (0.2 mm internal diameter) was placed on the left renal artery of rats. After operation the rats were divided into 4 groups sham group, 2K1C (two-kidney one clip) group, 2K1C+Arg (2K1C and L-Arg 150 mg/kg x d(-1) by drinking) group, and 2K1C+NAME (2K1C and L-NAME 10 mg/kg x d(-1) i.p.) group. The animals were studied at two time points (4 and 7 weeks after operation) corresponding to phases I and II of Goldblatt hypertension. The animals were deeply anesthetized with pentobarbital and perfused by the cardiac route with saline (100 ml) and freshly prepared 4% paraformaldehyde in phosphate buffer (300 ml). The caudal medulla was removed, then placed in 25% sucrose in PB for 12 h in a 4 degrees C fridge. The 40 microm coronal slices of brainstems were cut with cryostat, collected in PBS for nNOS study by immunohistochemistry. The results showed that (1) only a few neuronal nitric oxide synthase (nNOS) positive neurones were found in caudal medulla, including the depressor area of the ventral surface of medulla oblongata (VSMd) and the caudal pressor area (CPA) of the sham operated animals. The number of nNOS positive neurons in caudal medulla was significantly increased in 2K1C Goldblatt hypertension rats at 4 and 7 weeks. (2) The number of nNOS positive neurons in VSMd and CPA were 2K1C+Arg > 2K1C >2K1C +NAME > sham. (3) L-Arg enhanced the expression of nNOS whereas L-NAME inhibited the expression of nNOS in caudal medulla. (4) The character of nNOS expression was similar in Goldblatt hypertension rats at 4 weeks with that of the rats at 7 weeks.
Animals ; Hypertension, Renovascular ; enzymology ; physiopathology ; Male ; Medulla Oblongata ; enzymology ; metabolism ; Nitric Oxide Synthase ; biosynthesis ; Rats ; Rats, Sprague-Dawley

The activation of protein kinase C (PKC) is not only a pivotal node during cardiac hypertrophy in chronic pressure-overloaded heart, but also involved in the regulation of cardiac contractility. The aim of this paper was to observe PKC modulation in cardiac contractility at different stages of cardiac hypertrophy in spontaneously hypertensive rat (SHR). The cardiomyocytes were isolated from 4- and 10-month-old normotensive Wistar-Kyoto (WKY) and SHR rat hearts. The shortening amplitude of unloading contraction in cardiomyocytes was observed by an Edge Detector system. The shortening amplitude in WKY rat cardiomyocytes increased gradually as the stimulating frequency increased from 1 to 3 Hz. The shortening amplitude was positively correlated with stimulating frequency. The shortening amplitude in 4-month-old SHR group was enhanced as compared with that in WKY group at the same stimulating frequency. When the stimulating frequency increased, the shortening amplitude did not increase in 4-month-old SHR group. There was no difference in shortening amplitude between 10-month-old SHR and WKY groups at 1-Hz stimulating frequency. But the shortening amplitude in 10-month-old SHR group decreased when the stimulating frequency increased to 3 Hz. The perfusion of 50, 100 or 200 nmol/L PMA (a non-specific agonist of PKCs) significantly reduced the shortening amplitude in WKY and SHR groups. The shortening amplitude was reduced to (69.8±1.9)%, (58.2±2.2)% and (22.7±2.5)% (all P<0.01), respectively, in WKY group, as compared with that in HEPES buffer perfusion (100%). It was reduced to (6.1±0.7)%, (2.4±0.2)% and (12.5±2.6)% (all P<0.01) in 4-month-old SHR group, and (65.7±1.6)%, (53.9±4.0)% and (16.3±2.0)% (all P<0.01) in 10-month-old SHR group. The decreases in shortening amplitude in 4-month-old SHR group were more significant than those in 10-month-old SHR and WKY groups. On the other hand, 200 nmol/L of staurosporine, an inhibitor of PKC, significantly increased the shortening amplitude of cardiomyocytes in WKY, 4-month-old SHR, and 10-month-old SHR groups by (63.63±4.53)%, (80.82±4.61)% and (80.97±4.59)%, respectively (all P<0.05). The results suggest that the PKC isoforms inducing negative inotropic effect may be activated at the early stage of cardiac hypertrophy in SHR rats, and are possibly involved in the modulation of cardiac contractility. The activated PKC isoforms return to their normal activity at the stable stage of cardiac hypertrophy in SHR rats.
Animals ; Cardiomegaly ; enzymology ; Heart ; physiopathology ; Hypertension ; physiopathology ; Myocardial Contraction ; Myocytes, Cardiac ; enzymology ; Protein Kinase C ; metabolism ; Rats ; Rats, Inbred SHR ; Rats, Inbred WKY

OBJECTIVETo evaluate the liver injury in rats of abdominal infection complicated with abdominal compartment syndrome(ACS).

METHODSSD rats were divided into four groups, including the sham group, the abdominal infection group, the ACS group, and the abdominal infection plus ACS group (combination group). Rats were sacrificed at 1 h, 6 h, 12 h, 24 h after operation with 6 rats at each time point. Blood specimens were collected for liver function testing. Liver tissues were assessed by pathologically examination with hepatic injury severity scoring(HISS). The expressions of Toll-like receptor 4 (TLR4),TNF-α and IL-6 were examined by reverse transcription- polymerase chain reaction.

RESULTSAt 24 h after operation, as compared to the sham group(18.2±1.3) U/L and (105.6±25.5) U/L, ALT and AST increased obviously in the abdominal infection group(68.2±17.5) U/L and (184.6±36.1) U/L, the ACS group (305.2±128.2) U/L and (638.0±104.8) U/L and the combination group (409.2±67.1) U/L and (743.2±250.2) U/L, while the combination group had a higher level as compared to the infection group and the ACS group(all P<0.05). HISS scores were significantly higher in the abdominal infection group(5.0), the ACS group(5.5) and the combination group(7.0) as compared to the sham group(1.5), but no significant differences were found among the three groups at 24 h after operation. Expressions of TLR4, TNF-α and IL-6 were significantly higher in combination group than those in the other three groups.

CONCLUSIONSLiver function can be affected by abdominal infection and ACS. Abdominal infection plus ACS results in more severe liver injury.

Alanine Transaminase ; blood ; Animals ; Aspartate Aminotransferases ; blood ; Disease Models, Animal ; Female ; Interleukin-6 ; metabolism ; Intra-Abdominal Hypertension ; enzymology ; physiopathology ; Intraabdominal Infections ; enzymology ; physiopathology ; Liver ; physiopathology ; Rats ; Rats, Sprague-Dawley ; Toll-Like Receptor 4 ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo investigate the expression of Rho-kinase and heme oxygenase and the interaction among NOS/NO, HO/CO and RhoA/Rho-kinase in the corpus cavernosum of spontaneous hypertensive rats (SHRs).

METHODSA series of electric stimuli were applied to the corpus cavernosum nerves of 7 SHRs, the changes of ICP/MAP observed continuously and the expressions of ROCK2, HO-2 and eNOS analyzed by Western blot and immunohistochemistry. Another 7 WKY rats were taken as controls.

RESULTSCompared with the controls, ICP/MAP did not rise obviously (P < 0.05), HO-2 dropped sharply (P = 0.006) and the expression of the ROCK2 protein was elevated markedly (P = 0.017) in the SHRs. Immunohistochemistry showed HO-2 to be distributed in the smooth muscle cells and nervous cells of the corpus cavernosum, and eNOS mainly in the vascular endothelial cells. The expressions of HO-2 and eNOS were obviously reduced in the SHRs.

CONCLUSIONNOS/NO, HO/CO and RhoA/Rho-kinase are related with erectile dysfunction in SHRs and may interact on one another.

Animals ; Blotting, Western ; Erectile Dysfunction ; enzymology ; physiopathology ; Heme Oxygenase (Decyclizing) ; metabolism ; Hypertension ; enzymology ; physiopathology ; Immunohistochemistry ; Male ; Penis ; enzymology ; Rats ; Rats, Inbred SHR ; Rats, Inbred WKY ; rho-Associated Kinases ; metabolism

OBJECTIVES: The present study was aimed at exploring whether the pathogenesis of hypertension is related with an altered expression of nitric oxide synthase (NOS) isozymes, i.e., bNOS, iNOS and ecNOS. METHOD: By Western blot analysis, the expression of NOS isozymes were determined in the kidney isolated from spontaneously hypertensive rats (SHR) and their normotensive control, Wistar-Kyoto rats (WKY). The NOx (nitrite/nitrate) contents were also determined in the kidney and plasma. RESULTS: The plasma NOx was significantly increased in SHR compared with that in WKY. The basal level of NOx was higher in the medulla and cortex of the kidney in SHR compared with that in WKY rat. bNOS proteins were expressed higher in the outer medulla and cortex, and iNOS proteins were higher in the inner medulla, outer medulla and cortex in SHR. ecNOS expression did not significantly differ between the SHR and WKY. CONCLUSIONS: These results indicate that the NO generation may not be impaired, but rather increased. It is likely that the increased expression of NOS isozymes is a counter-reactive phenomenon secondary to the increased blood pressure in this model of hypertension.
Animal ; Hypertension/physiopathology ; Hypertension/enzymology* ; Isoenzymes/metabolism ; Kidney/enzymology* ; Male ; Nitrates/metabolism ; Nitrates/blood ; Nitric Oxide/biosynthesis ; Nitric-Oxide Synthase/metabolism* ; Nitrites/metabolism ; Nitrites/blood ; Rats ; Rats, Inbred SHR ; Rats, Inbred WKY

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 brain-stem response (ABR) was measured by Spirit 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.
Aging ; Animals ; Cholinesterases ; metabolism ; Cochlea ; metabolism ; physiopathology ; Evoked Potentials, Auditory, Brain Stem ; Female ; Hypertension ; complications ; enzymology ; physiopathology ; L-Lactate Dehydrogenase ; metabolism ; Male ; Presbycusis ; etiology ; physiopathology ; Rats ; Rats, Inbred SHR ; Rats, Wistar

OBJECTIVE: To investigate the impact of renal denervation on the blood pressure, plasma renalase content and expression of renalase and tyrosine hydroxylase (TH) in the idney of spontaneous hypertensive (SH) rats and to explore the role of renal denervation in lowering the blood pressure. METHODS: SH rats were randomly assigned into a baseline group, a surgery (renal denervation) group, a sham group and a control group (n=48). WKY rats matched in age (n=12) served as a baseline control group. All rats were housed until 12 weeks old. Then, the rats in the baseline group and the WKY group were sacrificed whose blood and kidney were collected for examination. In the renal denervation group, the sham group and the control group, the blood pressure was monitored continuously. One week and 6 weeks after the renal denervation, 6 rats in each group were sacrificed whose blood and kidney were collected. ELISA was employed to measure the plasma renalase and Western blot assay done to detect the expression of TH and renalase in the kidney. RESULTS: Compared with WKY rats, blood pressure significantly increased and TH protein expression markedly elevated (P<0.05) in SH rats in the baseline group, but plasma renalase content and protein expression of renalase in the kidney dramatically reduced (P<0.05). One week after the surgery, the mean arterial pressure and TH protein expression in the surgery group were lowered compared with the baseline group and dramatically reduced compared with the sham group and the control group (P<0.05). In the surgery group, the renalase level was markedly increased compared with the baseline group, the sham group, and the control group (P<0.05). Six weeks after the renal denervation, the mean arterial pressure and TH level in the surgery group were significantly increased but the renalase content and expression markedly reduced compared with those 1 week, but there were no marked differences among the surgery group, the sham group, and the control group (P>0.05). No pronounced differences in the above variables were found between the sham group and the control group at any time point (P>0.05). CONCLUSION Renal denervation can lower the blood pressure, which may attribute to the suppression of sympathetic nerves, increase in plasma renalase content and renalase expression in the kidney.
Animals ; Blood Pressure ; physiology ; Hypertension ; surgery ; Kidney ; enzymology ; innervation ; Male ; Monoamine Oxidase ; blood ; metabolism ; Rats ; Rats, Inbred SHR ; Sympathectomy ; methods ; Sympathetic Nervous System ; physiopathology ; Tyrosine 3-Monooxygenase ; metabolism

OBJECTIVETo observe myocardial cathepsin (Cat) S expression and activity in hypertensive heart failure rats.

METHODSThe expression and activity of Cat S were determined in the left ventricular (LV) myocardium (LVM) of Dahl salt-sensitive rats fed either a high-salt (HS, 8%) or low-salt (LS, 0, 3%, controls) diet starting at age 7 weeks for 12 weeks (hypertrophy model, H-LVH) or 19 weeks (heart failure model, H-HF). Age-matched rats served as controls and human normal, hypertensive and heart failure myocardial specimen were also examined for changes on the expression and activity of Cat S.

RESULTSReverse transcription and real-time polymerase chain reaction analysis revealed significantly upregulated Cat S mRNA in rats with H-HF than in rats with H-LVH or in control rats and Cat S mRNA expression is negatively correlated with LVEF (r = -0.88, P < 0.05). In situ and immunohistochemistry examinations showed that Cat S was localized predominantly in cardiac myocytes (CMCs) and coronary vascular smooth muscle cells (SMC). Elastic lamina fragmentations and Cat S-dependent elastolytic activity were significantly increased in H-HF-rats. The expression of interleukin-1 beta was also increased in the LVM of H-HF rats, and this cytokine was found to increase the Cat S protein expression in culture neonatal CMCs. Similar results were revealed in human myocardial specimens.

CONCLUSIONElastolytic Cat S might play an important role in the pathogenesis of myocardial remodeling and heart failure and Cat S might serve as a novel therapeutic target in preventing or reversing hypertension induced LV remodeling and heart failure.

Adult ; Aged ; Animals ; Case-Control Studies ; Cathepsins ; metabolism ; Disease Models, Animal ; Enzyme Activation ; Heart Failure ; enzymology ; etiology ; physiopathology ; Humans ; Hypertension ; complications ; enzymology ; Male ; Middle Aged ; Myocardium ; enzymology ; Rats ; Rats, Inbred Dahl ; Ventricular Function, Left ; Ventricular Remodeling

OBJECTIVETo investigate the effect of panax notoginseng saponins (PNS) injection on pulmonary artery pressure and the expression of p38MAPK in lung tissue of rats subjected to chronic hypoxia.

METHODSThirty adult male Sprague Dawley rats were randomly divided into three groups (ten in each group): rats in control group were exposed to normoxic condition and the rats in hypoxia group and PNS group were subjected to 4-week hypoxia, and PNS injection (50 mg · kg(-1) · d(-1)) was administrated intraperitoneally at 30 min in the PNS group daily before the rats were kept in the hypoxic chamber, while rats in the other two groups received equal dose of normal saline instead. After chronic hypoxia, mean pulmonary artery pressure (mPAP) and mean carotid artery pressure (mCAP) were measured. The heart and lung tissues were harvested, and right ventricle (RV) and left ventricle plus ventricular septum (LV+S) were weighed to calculate the ratio of RV/(LV+S). The expression of p38MAPK mRNA was determined by reverse transcription-polymerase chain reaction, the quantity of phosphorylated p38MAPK (p-p38MAPK) in rat lung tissues and pulmonary arterioles was determined by Western blot and immunohistochemistry.

RESULTSCompared with the control group, mPAP and the ratio of RV/(LV+S) in the hypoxia group were increased, the expression of p-p38MAPK in pulmonary arterioles and p38MAPK mRNA in the lung were higher (P<0.05). The changes of these parameters in the hypoxia group were significantly attenuated by PNS treatment (P<0.05).

CONCLUSIONPNS injection was shown to prevent hypoxic pulmonary hypertension at least partly by regulating p38MAPK pathway.

Animals ; Arterioles ; drug effects ; metabolism ; Blood Pressure ; drug effects ; Blotting, Western ; Carotid Arteries ; drug effects ; physiopathology ; Disease Models, Animal ; Heart Ventricles ; drug effects ; physiopathology ; Hemodynamics ; drug effects ; Hypertension, Pulmonary ; complications ; enzymology ; physiopathology ; Hypoxia ; complications ; enzymology ; physiopathology ; Injections ; Lung ; drug effects ; enzymology ; pathology ; physiopathology ; MAP Kinase Signaling System ; drug effects ; Male ; Panax notoginseng ; chemistry ; Pulmonary Artery ; drug effects ; physiopathology ; RNA, Messenger ; genetics ; metabolism ; Rats, Sprague-Dawley ; Saponins ; administration & dosage ; pharmacology ; p38 Mitogen-Activated Protein Kinases ; genetics ; metabolism