The effect of large-conductance calcium-activated potassium channels on the migration of pericytes in the mice of senile cochlear stria vascularis / 中华耳鼻咽喉头颈外科杂志

Objective: To investigate whether large conductance calcium-activated potassium channel (BK(Ca)) was involved in the migration of pericytes (PC) in the mice of senile cochlear stria vascularis capillaries PC. Methods: C57BL/6J mice were divided into 3-month (n=10) and 12-month groups (n=10). Auditory brainstem response (ABR) was used to test the hearing threshold of each group. The immunofluorescence was used to detect the expression changes of osteopontin (OPN) and β-BK(Ca) channels on cochlear stria vascularis PC. The morphological changes of perivascular cells in cochlea were observed by transmission electron microscope (TEM). Cell experiment: The PC, which were in the stria vascularis of the cochlea were primary cultured and identified. A cell senile model was made with D-gal. The appropriate intervention concentration of low galactose (D-gal) was determined by CCK8. β-galactosidase (SA-β-gal) staining was used to evaluate the cell decrept level. The change of BK(Ca) channels current on PC were recorded by whole cell patch clamp technique. The expression of BK(Ca) channels on PC was detected by immunofluorescence. The migration and invasion ability of two groups were detected by using Scratch test and Transwell. The levels of OPN and β-BK(Ca) channels were detected by Western blot. SPSS 22.0 software was used to analyze the data. Results: The ABR threshold in the 12-month group was higher than 3-month group (t=12.66, P<0.01). In the 12-month group, the expression of β-BK(Ca) channel was lower and the expression of OPN was increased (t=14.64, P<0.01; t=20.73, P<0.01). In TEM, cochlear stria vascularis PC were tightly connected to endothelial cells in 3-month group, while PC were loosely connected to endothelial cells or PC soma were separated from the capillary in 12-month group. Cell experiment: The positive rate of PC in the primary cultured cochlear stria vascularis is above 95%. Compared with the SA-β-gal stained cells in the control group, the positive rate of 15 mg/ml D-gal intervention PC was 85% (t=36.90, P<0.01). Whole cell patch clamp BK(Ca) channels current decreased in the D-gal group compared with the young group PC (t=12.18, P<0.05). The OPN expression in the senile group was higher than control group (t=16.30, P<0.01), while the β-BK(Ca) channels expression was decreased (t=11.98, P<0.01; t=15.72, P<0.05), and migration ability raised (t=7.91, P<0.01;t=7.59, P<0.01). After intervened of BK(Ca) channels specific blocker IBTX in the D-gal group, the expression of OPN and migration were increased (t=4.26, P<0.05; t=5.88, P<0.01; t=21.97, P<0.01). Conclusion: PC migration capacity were increased during the senile period, and the expression of β-BK(Ca) channel was decreased. The administration of IBTX, a specific blocker of BK(Ca) channel, at the cell level could increase the migration capacity, suggesting that BK(Ca) might be involved in the migration of PC in the stria vascularis of the aging cochlea.

Treatment of thoracolumbar spinal tuberculosis with single posterior debridement, bone grafting, internal fixation and local chemotherapy / 中国骨伤

<p><b>OBJECTIVE</b>To evaluate the clinical effects of single posterior debridement, bone grafting, internal fixation and local chemotherapy in treating thoracolumbar spinal tuberculosis.</p><p><b>METHODS</b>From February 2009 to September 2012,11 patients with thoracolumbar spinal tuberculosis were treated by single posterior debridement, bone grafting, internal fixation and local chemotherapy. There were 7 males and 4 females, aged from 27 to 65 years old with an average of 53.7 years. The courses of disease was from 3 months to 2 years with the mean of 9 months. According to ASIA standard of spinal cord injury, 3 cases were grade C and 8 cases D. After treatment, clinical effects were evaluated by ASIA grade, visual analogue score (VAS) and Oswestry Disability Index (ODI); kyphosis Cobb angle change was observed by X-rays.</p><p><b>RESULTS</b>Eleven patients were followed up from 12 to 29 months with an average of 18 months. ASIA grade of spinal cord injury, 3 patients with grade C improved to grade D in 2 cases and grade E in 1 case 8 patients with grade D improved to grade E in 7 cases and unchanged in 1 case. VAS decreased from preoperative 6.10 ± 1.30 to 1.70 ± 0.80 at 3 d after operation (P < 0.05). ODI improved from preoperative (68.36 ± 10.41)% to (14.55 ± 8.99)% (P < 0.05) at 3 d after operation. Kyphotic Cobb angle was corrected from preoperative (22.64 ± 4.84)° to (4.27 ± 1.49)° (P < 0.05) on the 3rd day after operation, and angle loss was mild at final follow-up, there was no significant difference between postoperative at 3 d and final follow-up.</p><p><b>CONCLUSION</b>Single posterior debridement, bone grafting, internal fixation and local chemotherapy for the treatment of thoracolumbar spinal tuberculosis can effectively remove the lesion, improve nerve function and correct deformity, has advantage of single incision, little trauma, and low recurrence rate. But it still need long-term and systemic treatment with anti-TB drugs.</p>

Effect of AT₁ receptor on changes of tyrosine hydroxylase-immunoreactivity in rostral ventrolateral medulla induced by brain cholinergic stimuli in rats / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the effect of AT₁ receptor on the changes of tyrosine hydroxylase-immunoreactivity (TH-IR) in rostral ventrolateral medulla (RVLM) induced by brain cholinergic stimuli in rats.</p><p><b>METHODS</b>Male SD rats were randomly divided into 4 groups: NS + CBC group, Los + CBC group, Los + NS group and NS + NS group. AT₁ was blocked by pretreatment of 20 μg losartan in Los + CBC and Los + NS groups; intracerebroventricular injection of 0.5 μg carbachol was used for cholinergic stimuli in NS + CBC and Los + CBC groups; normal saline (NS) was used for control. The output amount of natrium in kidney, glomerular filtration rate (GFR) and renal plasma flow (PRF) were observed. The changes of TH-IR in the RVLM were observed by immunohistochemistry.</p><p><b>RESULT</b>In NS + CBC group carbachol induced potent natriuresis, after pretreatment of losartan the natriuretic effect was partially inhibited in Los + CBC group. Both the number and optical density of TH-IR positive neurons in NS + CBC group were markedly increased than those in NS + NS group (P < 0.05); while those in Los + CBC group were significantly lower than those in NS+CBC group (P < 0.05). Intracerebroventricular injection of carbachol and losartan had no effect on GFR and RPF(P > 0.05).</p><p><b>CONCLUSION</b>The results suggest that cholinergic stimuli can induce potent natriuresis and increase the activity of adrenergic neurons in the RVLM; the above effects can be down regulated by blockade of brain AT₁ receptor.</p>

Betulinic acid ameliorates impairment of endothelium-dependent relaxation induced by oxidative stress in rat aorta / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the effect of betulinic acid (BA) on relaxation in isolated rat aortic rings and its antioxidant property on oxidative stress of blood vessels.</p><p><b>METHODS</b>Aortic rings were isolated and BA was cumulatively added into organ bath. Isometric tension of endothelium intact or endothelium denuded thoracic aortic rings previously contracted by phenylephrine (PE) was recorded. Then aortic rings were randomly divided into normal control group, BA control group, H(2)O(2) group and BA+H(2)O(2) group, after being previously contracted by PE, isometric tension of endothelium-dependent relaxation induced by Ach was recorded.</p><p><b>RESULT</b>Exposure of intact endothelium rings previously contracted by PE to BA at the concentrations of 10(-7) mol/L-10(-4) mol/L evoked a significant concentration dependent relaxation, which was inhibited by pretreatment with N omega-nitro-L-arginine methyl ester (L-NAME, 10(-4)mol/L), but not by indometacin (10(-5)mol/L). The pD2 value of BA was 5.24 ± 0.04, and the EC(50)value was 2.45 x 10(-6)mol/L. Exposure of endothelium denuded rings previously contracted by PE to BA did not affect the relaxation in isolated aortic rings. ACh induced a dose-dependent relaxation that was weakened by pretreatment with H(2)O(2) (5 10(-4) mol/L) for 15 min. The EC(50) of BA markedly attenuated the inhibition of relaxation induced by H(2)O(2).</p><p><b>CONCLUSION</b>BA can evoke a concentration-dependent relaxation in aortic rings previously contracted by PE, which may be mediated by NO. And the decrease of endothelium-dependent relaxation in rat aortic rings exposed to H(2)O(2) can be markedly attenuated by BA, which may be mediated by reducing oxidative stress and maintaining the activity of NO in aortic rings.</p>

Activation of mitochondrial aldehyde dehydrogenase 2 and inhibition of mitochondrial permeability transition pore involved in cardioprotection of ethanol postconditioning / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate whether activation of mitochondrial aldehyde dehydrogenase 2 (ALDH2) and inhibition of mitochondrial permeability transition pore (mitoPTP) were involved in the cardioprotection of ethanol postconditioning in isolated rat heart.</p><p><b>METHODS</b>Hearts isolated from male Sprague-Dawley rats were perfused on a langendorff apparatus and subjected to 30 min of regional ischemia (occlusion of left anterior descending artery) followed by 120 min of reperfusion. The ventricular hemodynamic parameters and lactate dehydrogenase (LDH) release during reperfusion were measured. Infarct size was measured by TTC staining method and the expression of ALDH2 at mRNA level of left anterior myocardium was detected by RT-PCR.</p><p><b>RESULT</b>In contrast to ischemia and reperfusion, ethanol postconditioning improved the recovery of left ventricular developed pressure, maximal rise/fall rate of left ventricular pressure during reperfusion, reduced LDH release and infarct size. The expression of ALDH2 mRNA level was increased. Administration of mitoPTP activator atractyloside attenuated the effect of ethanol postconditioning, LDH release and infarct size were increased, and the recovery of hemodynamic parameters was inhibited. The expression of ALDH2 mRNA was decreased.</p><p><b>CONCLUSION</b>Ethanol postconditioning has cardioprotection effect, which may be associated with upregulating mitochondrial ALDH2 mRNA expression and inhibiting the opening of mitochondrial permeability transition pore.</p>

Hemodynamics and aortic tension induced by two septic shock models in rats / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To compare the ventricular-dynamic parameters and thoracic aorta tension induced by two septic shock models in rats.</p><p><b>METHODS</b>Septic shock models were induced by cecal ligation or puncture (CLP) and intraperitoneal injection of lipopolysaccharide (LPS) in rats. The carotid artery was cannulated and connected to a pressure transducer to determine mean arterial blood pressure (MABP). Ventricular dynamic parameters, including heart rate (HR), left ventricular developed pressure (LVDP) and maximal rise/fall velocity of ventricular pressure (± dP/dtmax) were determined. Isolated thoracic rings were mounted on an organ bath and the tension of the vessel was recorded.</p><p><b>RESULT</b>The mortality was 65.2% in CLP shock rats, but no death in LPS shock rats. The MABP and HR of CLP rats were decreased more prominently than those of LPS rats (P < 0.01). Contraction induced by high K(+) (60 mmol/L) or 10⁻⁶ mol/L phenylephrine (PE) in endothelium-intact and endothelium-denuded aortic rings was all attenuated, but in LPS rats it was more prominent (P < 0.01).</p><p><b>CONCLUSION</b>Two rat septic shock models can decrease ventricular-dynamic parameters and vasoconstriction responsiveness of aorta. The ventricular-dynamic parameters decrease more prominently in CLP model, while vasoconstriction responsiveness of aorta changes more in LPS model.</p>

Effect of nitric oxide synthase inhibitors on the changes of hemodynamic parameters and aortic tension induced by septic shock in rats / 中国应用生理学杂志

<p><b>AIM</b>To investigate the effect of three types of nitric oxide synthase inhibitors on the changes of hemodynamic parameters and thoracic aorta tension induced by septic shock in rats.</p><p><b>METHODS</b>We used cecal ligation and puncture (CLP) method to establish septic shock in rats, and the three types of nitric oxide synthase inhibitors were injected after CLP. The carotid artery was cannulated and connected to a pressure transducer to determine mean arterial blood pressure (MABP). Ventricular dynamic parameters were determined following intraventricular cannulation via the carotid artery, including heart rate (HR), left ventricular developed pressure (LVDP), maximal rise/fall velocity of ventricular pressure (+/- dP/dt(max)). Isolated thoracic rings were mounted on an organ bath and the tension of the vessel was recorded.</p><p><b>RESULTS</b>(1) After using L-NAME, AMG and 7-NI the mortality decreased to 50.0%, 37.5%, and 42.1%, respectively (from 65.2% in septic shock rats); (2) The MABP in septic shock rats partly recovered after using the NOS inhibitors, all ventricular dynamic parameters partly recovered after using the inhibitors; (3) The hyporeactivity of endothelium-denuded aortic rings to vasoconstrictors induced by septic shock was partly recovered by pretreatment with the inhibitors. However, only L-NAME or 7-NI could inhibit the decrease of vasoconstriction induced by septic shock in endothelium-intact aortic rings.</p><p><b>CONCLUSION</b>The three types of nitric oxide synthase inhibitors can improve the hemodynamic parameters and vasoconstriction responsiveness of endothelium-denuded aorta of septic shock rats. Furthermore, L-NAME and 7-NI improve the responsiveness of endothelium-intact aorta.</p>

Involvement of nitric oxide in negative inotropic effect of interferon-alpha in rat cardiac muscle / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the effects and underlying mechanisms of interferon-alpha (IFN-alpha) on the isolated Langendorff perfused rat hearts and the isolated papillary muscles.</p><p><b>METHODS</b>The left ventricular developed pressure (LVDP), maximal rise/fall rate of left ventricular pressure (+/-dP/dt(max)), left ventricular end-diastolic pressure (LVEDP), heart rate (HR) and coronary flow (CF) were recorded in isolated Langendorff perfused rat hearts. The average contractile force was measured in the isolated papillary muscles of rat right ventricle.</p><p><b>RESULT</b>IFN-alpha (10 - 10,000 U/ml) induced a concentration-dependent decrease of LVDP and +/-dP/dt(max), and increase of LVEDP and CF in the isolated perfused rat heart (P < 0.05), and decrease of the average contractile force of the papillary muscle (P <0.05). Pretreatment with L-NAME (10(-4) mol/L), an inhibitor of nitric oxide synthase, attenuated the effect of IFN-alpha in the isolated rat hearts and the isolated papillary muscles (P <0.05). Isoproterenol (ISO, 10(-9) - 10(-6)mol/L) increased the contractile force of the rat papillary muscles in a concentration-dependent manner. Perfusion for 10 min with IFN-alpha at 1,000 U/ml attenuated the enhancing effect of ISO. Pretreatment with L-NAME reduced the effects of IFN-alpha on the isolated papillary muscles.</p><p><b>CONCLUSION</b>IFN-alpha may induce a negative inotropic effect in normal and beta-adrenergic activated cardiac muscles and this effect at least partly be mediated by nitric oxide.</p>

Vascular effect of extract from mulberry leaves and underlying mechanism / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the vascular activity of extract from mulberry leaves (EML) on rat thoracic aorta and the underlying mechanism.</p><p><b>METHODS</b>Isolated thoracic rings of Sprague-Dawley rats were mounted on the organ bath and the tension of the vessel was recorded.</p><p><b>RESULT</b>(1) EML produced a concentration-dependent vasorelaxation of aorta preconstricted by high K(+) (60 mmol/L) or 10(-6) mol/L phenylephrine (PE) in endothelium-intact and endothelium-denuded arteries. (2) EML at EC(50) concentration reduced the calcium dose-response curve. (3) After incubation of aorta with verapamil, EML induced vasocontraction of aorta preconstricted by PE, which was abolished by ruthenium red.</p><p><b>CONCLUSION</b>The vascular effect of EML is biphasic, the vasorelaxation is greater than the vasocontraction. The vasorelaxation induced by EML may be mediated by inhibition of voltage-and receptor-dependent calcium channels in vascular smooth muscle cells, while the vasocontraction is via activation of ryanodine receptor in endoplasmic reticulum.</p>

Comparison of vasodilatation effect between quercetin and rutin in the isolated rat thoracic aorta / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To determine the possible difference in vasodialtation effect of quercetin and rutin.</p><p><b>METHODS</b>The isolated rat thoracic aorta was treated with phenylephrine (PE), and the effects of quercetin and rutin on the preconstricted aorta rings with or without endothelium were determined by organ bath technique. Nitric oxide synthase inhibitor L-N(G)-nitroarginine methyl-ester (L-NAME), guanylyl cyclase inhibitor methylene blue, cyclooxygenase inhibitor indomethacin were used to explore the mechanism.</p><p><b>RESULTS</b>Quercetin (10-160 micromol/L) caused vasorelaxation of aorta rings preconstricted with PE in endothelium-intact and denuded aorta rings in a dose-dependent manner. Rutin(10-160 micromol/L) caused dose-dependent vasorelaxation in endothelium-intact rings preconstricted with phenylephrine, but not in denuded aorta rings. The maximal response (Rmax) values calculated from vasorelaxation curves of quercetin and rutin were (77.20+/-6.11)% and (44.28+/-7.48)%, respectively. There was no difference between median effective concentration (EC(50)) values of quercetin and rutin. Pretreatment with L-NAME (0.1 mmol/L) abolished the vasorelaxation by rutin,but did not influence the vasodilating effect of quercetin in endothelium-intact rings. Pretreatment with methylene blue (10 mmol/L) canceled the vasorelaxation both by quercetin and rutin. Pretreatment with indomethacin (10 micromol/L) attenuated the vasodilatation of quercetin, but did not affect the vascular effect of rutin.</p><p><b>CONCLUSION</b>The vasodilatation effect of quercetin is more potent than rutin. The vasodilatation effect of quercetin might be mediated by guanylyl cyclase and cyclooxygenase-dependent pathway, while the vasodilatation by rutin might be via nitric oxide-guanylyl cyclase pathway.</p>