酶消化法培养老龄SD大鼠血管平滑肌细胞

目的：采用酶消化法培养老龄SD大鼠血管平滑肌细胞,为血管疾病,特别是为动脉粥样硬化研究提供大量的原代平滑肌细胞。方法：无菌取老龄SD大鼠主动脉,0.2%Ⅱ型胶原酶消化分离细胞,采用自然纯化、差速贴壁纯化平滑肌细胞,免疫组化鉴定平滑肌细胞α肌动蛋白。结果：免疫组化染色显示细胞纯度在95%以上。结论：酶消化法分离获取SD大鼠平滑肌细胞方法简单,易掌握,采用本方法可稳定获得大量的平滑肌细胞供实验使用。     

糖尿病大鼠冠状动脉平滑肌细胞中大电导钙离子激活钾通道电流和钙离子浓度变化

目的探讨糖尿病大鼠冠状动脉平滑肌细胞中大电导钙离子激活钾通道(BK通道)电流及钙离子浓度的变化。方法 40只SD大鼠随机均分为正常对照组(A组)和糖尿病组(B组)。采用链脲霉素腹腔内注射建立糖尿病大鼠模型,酶消化法分离冠状动脉平滑肌细胞,全细胞膜片钳实验和荧光测定方法分别检测冠状动脉平滑肌细胞BK通道电流和钙离子浓度。结果与A组相比,当刺激电压大于60mV时,B组冠状动脉平滑肌细胞BK通道电流密度明显下降(P<0.05);A组冠状动脉平滑肌细胞内钙离子浓度明显低于B组[(103±23)nmol/L vs.(193±22)nmol/L](P<0.05)。结论冠状动脉平滑肌细胞中BK通道电流下降及细胞内钙离子浓度升高可能是糖尿病冠状动脉功能损伤的重要原因。     

Changes of large conductance Ca2+-activated K+ channel current and cytosolic calcium concentrations in coronary artery smooth muscle cells of rats with diabetes

目的 探讨糖尿病大鼠冠状动脉平滑肌细胞中大电导钙离子激活钾通道(BK通道)电流及钙离子浓度的变化.方法 40只SD大鼠随机均分为正常对照组(A组)和糖尿病组(B组).采用链脲霉素腹腔内注射建立糖尿病大鼠模型,酶消化法分离冠状动脉平滑肌细胞,全细胞膜片钳实验和荧光测定方法分别检测冠状动脉平滑肌细胞BK通道电流和钙离子浓度.结果 与A组相比,当刺激电压大于60 mV时,B组冠状动脉平滑肌细胞BK通道电流密度明显下降(P＜0.05);A组冠状动脉平滑肌细胞内钙离子浓度明显低于B组[(103±23) nmol/L vs.(193±22) nmol/L](P＜0.05).结论 冠状动脉平滑肌细胞中BK通道电流下降及细胞内钙离子浓度升高可能是糖尿病冠状动脉功能损伤的重要原因.     

High glucose enhance expression of matrix metalloproteinase—2 in smooth muscle cells

目的:通过用高糖对培养的大鼠主动脉平滑肌细胞进行干预,观察其对基质金属蛋白酶-2(MMP-2)表达的影响。方法:用组织贴块法体外培养大鼠主动脉平滑肌细胞,分组后分别予以葡萄糖0,1,5g/L进行干预。分别提取细胞总RNA和总蛋白分别进行逆转录PCR(RT-PCR),Westernblotting检测,同时取出条件培养基经酶谱法(zymography)检测分泌于培养基中的MMP-2活性。结果:经mRNA,蛋白和酶活性检测,均发现在葡萄糖浓度为5g/L时,MMP-2的表达水平较对照和1g/L时明显增加。结论:高糖促进血管平滑肌细胞和内皮细胞内MMP-2表达,提示血管细胞外基质的降解在糖尿病患者动脉粥样硬化发生机制中起着一定作用。     

酶消化法分离培养糖尿病大鼠结肠平滑肌细胞

目的探讨糖尿病(DM)大鼠结肠平滑肌细胞(SMC)的培养方法。方法建立DM大鼠模型,分离结肠,用酶消化法体外培养正常及DM大鼠结肠SMC,α-肌动蛋白免疫荧光鉴定。结果造模后大鼠体重(165±16.8)g,较正常组(286±14.5)g明显减轻(P<0.01);血糖(25.4±3.4)mmol/L,明显高于正常组(4.3±0.8)mmol/L(P<0.01)。正常结肠SMC培养7 d左右即可融合成片、相互交叉成多层,进行传代;DM大鼠结肠SMC需12～14 d融合成片,进行传代;传代后正常结肠SMC需3～4 d即可进行下一次传代,而糖尿病结肠SMC则需5 d。α-肌动蛋白免疫组化染色鉴定均为SMC。结论 DM大鼠结肠SMC增殖速度比正常SMC慢,培养条件也较正常SMC更严格,形态学上与正常SMC相似。     

SD新生大鼠耳蜗螺旋神经元的原代培养

目的建立用自制的鼠尾胶原联合胰酶消化法原代培养SD新生大鼠耳蜗螺旋神经元。方法采用出生3 d内的SD大鼠,取螺旋神经节组织,通过胰酶消化后在自制鼠尾胶原包被的培养皿中进行原代培养,应用神经微丝蛋白进行免疫组化鉴定。结果获得的螺旋神经元细胞在体外能较快地贴壁,可以存活、生长,细胞形态良好。结论自制鼠尾胶原联合胰酶消化的培养方法可获得良好状态的螺旋神经元细胞,为原代培养螺旋神经元提供了新思路。     

成人及成年大鼠雪旺细胞的体外培养

目的 探讨体外培养成人及大鼠雪旺细胞以获得高纯度细胞的方法.方法 分别用双酶分步消化法、预变性消化法及组织块反复接种法体外培养和纯化大鼠雪旺细胞,比较各种方法的纯度差异.结果 组织块反复接种法所获雪旺细胞纯度为(92.7±8.1)%,高于双酶分步消化法的(35.4±3.6)%及预变性消化法的(37.2±4.5)%(P＜0.01).结论 组织块反复接种法可获得高纯度的雪旺细胞.     

大鼠肺动脉平滑肌细胞原代培养及低氧对缺氧诱导因子- 1α的影响

目的获得活力稳定、高度纯化的体外培养大鼠血管平滑肌细胞,为肿瘤研究提供实验材料;并探讨低氧对抗肿瘤药物研究新靶点：缺氧诱导因子-1α（HIF-1α）的影响。方法无菌下取SD大鼠心肺组织,然后分离出肺动脉段,分离肺动脉中膜层,用组织块贴壁法培养,倒置相差显微镜观察细胞形态、普通免疫组织化学法（SP法）进行细胞鉴定。随后,将体外培养的大鼠PASMCs,设计常氧组、低氧组H2,H6,H12,H24,用Western blotting法检测HIF-1α的蛋白表达。结果用组织贴块法成功培养大鼠PASMCs,得到生长稳定、纯度高的PASMCs,且培养与纯化可以同时进行,可获得稳定传代的细胞;HIF-1α蛋白在常氧组有少量表达,在低氧条件下,其表达明显增加。结论成功建立体外大鼠肺动脉平滑肌细胞原代培养模型;低氧条件下促进其中HIF-1α的表达;这提示HIF-1α蛋白的表达可能是肿瘤细胞适应缺氧环境的重要原因。     

人和大鼠血管内皮细胞的培养和鉴定

目的：建立人和大鼠血管内皮细胞体外培养的模型，为内皮细胞相关性疾病的研究提供重要的实验基础。方法：采用0．1％I型胶原酶消化灌注法和组织块贴壁法分别获得人脐静脉内皮细胞和大鼠微血管内皮细胞，每天在倒置相差显微镜下进行观察，并用免疫荧光法分别进行鉴定。结果：经胶原酶消化法和组织块贴壁法获得的内皮细胞，经过镜下观察、免疫荧光法鉴定证明是人脐静脉内皮细胞和大鼠血管内皮细胞。结论：胶原酶消化法和组织块贴壁法都可获得血管内皮细胞，可为临床研究提供大量的种子细胞。     

鼠结肠平滑肌细胞的分离、培养与鉴定

目的建立体外培养鼠结肠平滑肌细胞的方法。方法应用酶解法分离大鼠的结肠平滑肌细胞,用含10％胎牛血清的DMEM液进行鼠结肠平滑肌细胞的原代培养及传代,并以免疫细胞化学对其进行鉴定。结果新鲜分离的结肠平滑肌细胞呈梭形,核居中。培养24h后细胞开始贴壁,3～5d后开始增殖,14d后细胞密集,呈峰谷样生长。细胞经平滑肌特异性肌动蛋白a-actin鉴定,确定为平滑肌细胞。结论应用酶解法可得到急性分离的鼠结肠平滑肌细胞,用含10％胎牛血清的DMEM液重悬分离得到的结肠平滑肌细胞,经过10d左右的培养可以获得结肠平滑肌细胞。该方法重复性好,效果稳定。     

GENDER-RELATED DIFFERENCES IN THE DEVELOPMENT OF ATHEROSCLEROSIS: STUDIES AT THE CELLULAR LEVEL

1. Calcified arteriosclerotic lesions have been recognized early in life as abnormalities in coronary arteries. 2. We examined coronary arterial plaques as an undecalcified tissue and revealed widespread mineralization within the plaque. Non-collagenous proteins that regulate calcification, such as osteopontin, have been identified within the atherosclerotic plaque. In vitro, smooth muscle cells derived from porcine coronary arteries express non-collagenous proteins and type I collagen. 3. We have demonstrated that oestrogen regulates the proliferation of smooth muscle cells obtained from the coronary arteries of sexually mature pigs. The inhibition of proliferation by β-estradiol occurred in coronary smooth muscle cells (VSMC) obtained from female animals and no proliferation was noted in VSMC isolated from intact male animals after exposure to β-estradiol. 4. The dynamic changes in matrix composition and cellular proliferation in atherosclerotic vessels may be responsible for the calcification associated with the atherosclerotic plaque.     

Reduced store-operated Ca2+ entry impairs mesenteric artery function in response to high external glucose in type 2 diabetic ZDF rats

Diabetes is a major risk factor for cardiovascular disease, affecting both endothelial and smooth muscle cells. Store-operated Ca²⁺ channels (SOCCs) have been implicated in many diabetic complications. Vascular dysfunction is common in patients with diabetes, but the role of SOCCs in diabetic vasculopathy is still unclear. Our research aimed to investigate the effects of high glucose (HG) on store-operated Ca²⁺ entry (SOCE) in small arteries. Small mesenteric arteries from type 2 diabetic Zucker fatty rats (ZDF) versus their non-diabetic controls (Zucker lean, ZL) were examined in a pressurized myograph. Vascular smooth muscle cells (VSMC) were isolated and intracellular Ca²⁺ was measured (Fura 2-AM). A specific protocol to deplete intracellular Ca²⁺ stores and thereby open SOCCs, as well as pharmacological SOCE inhibitors (SKF-96365, BTP-2), were used to artificially activate and inhibit SOCE, respectively. High glucose (40 mmol/L) relaxed arteries in a SKF-sensitive manner. Diabetic arteries exhibited reduced HG-induced relaxation, as well as reduced contraction after Ca²⁺ replenishment. Further, the rise in intracellular Ca²⁺ on account of SOCE is diminished in diabetic versus non-diabetic VSMCs and was insensitive to HG in diabetic VSMCs. The expression of SOCC proteins was measured, detecting a downregulation of Orai1 in diabetes. In conclusion, diabetes leads to a reduction of SOCE and SOCE-induced contraction, which is unresponsive to HG-mediated inhibition. The reduced expression of Orai1 in diabetic arteries could account for the observed reduction in SOCE.     

去势雌性大鼠主动脉平滑肌细胞雌激素受体的变化

目的：探讨绝经后血管平滑肌细胞雌激素受体的变化。方法：采用切除双侧卵巢、高脂饲料喂养造模大鼠，观察去势雌性大鼠血脂的变化，并应用免疫组化法(SP法)测定主动脉平滑肌细胞雌激素受体变化。结果：去势雌性大鼠血脂代谢紊乱，主动脉平滑肌细胞雌激素受体水平下降。结论：绝经后女性心血管疾病发病率与雌激素受体水平下降有关。     

Contribution of calcium dysregulation to impaired coronary artery contraction in Zucker diabetic fatty rats

Diabetic coronary artery injury is closely associated with Ca²⁺ dysregulation, although the underlying mechanism remains unclear. This study explored the role and mechanism of Ca²⁺ handling in coronary artery dysfunction in type 2 diabetic rats. Zucker diabetic fatty (ZDF) rats were used as the type 2 diabetes mellitus model. The contractility of coronary artery rings induced by KCl, CaCl₂, 5-HT and U46619 was significantly lower in ZDF rats than in Zucker lean rats. Vasoconstriction induced by 5-HT and U46619 was greatly inhibited by nifedipine. However, in the presence of 1 μM nifedipine or in the Ca²⁺-free KH solution containing 1 μM nifedipine, there was no difference in the vasoconstriction between Zucker lean and ZDF rats. Store-operated calcium channels (SOCs) were not involved in coronary vasoconstriction. The downregulation of contractile proteins and the upregulation of synthesized proteins were in coronary artery smooth muscle cells (CASMCs) from ZDF rats. Metformin reversed the reduction of vasoconstriction in ZDF rats. Taken together, L-type calcium channel is important for regulating the excitation–contraction coupling of VSMCs in coronary arteries, and dysregulation of this channel contributes to the decreased contractility of coronary arteries in T2DM.     

Vascular reactivity to vasopressin during diabetes: gender and regional differences

The isometric response to vasopressin of 2-mm-long segments of basilar, coronary, renal and tail arteries from male and female, control (normoglycemic) and streptozotocin-induced diabetic rats was studied. Vasopressin (10(-12)-3 x 10(-8) M) produced arterial concentration-dependent contraction, with a lower potency in coronary arteries from female than from male rats, and was similar for both genders in basilar, renal and tail arteries. This contraction was reduced by diabetes in basilar and coronary arteries, increased in renal arteries, and not modified in tail arteries, in both genders. Inhibition of nitric oxide synthesis with N(W)-nitro-L-arginine methyl ester (L-NAME, 10(-4) M) increased the contraction to vasopressin in coronary arteries from control female and diabetic female rats; as well as in renal arteries from control male and control female rats, but not in any other experimental group. Inhibition of cyclooxygenase with meclofenamate (10(-5) M) reduced the contraction to vasopressin in basilar arteries from diabetic female rats and in renal arteries from diabetic male rats, but not in any other experimental group. These results suggest that the response to vasopressin (a) has lower potency in female coronary arteries due to higher nitric oxide production; (b) is reduced by diabetes in basilar and coronary arteries from both genders, by mechanisms independent of nitric oxide and prostanoids; and (c) is increased by diabetes in renal arteries due to reduced production of nitric oxide in females, and to both reduced production of nitric oxide and increased production of prostanoids in males. Therefore, the effects of diabetes on vascular reactivity to vasopressin may differ between vascular beds, and the mechanisms underlay these effects may be distinct between genders.     

降钙素基因相关肽对糖尿病大鼠血管平滑肌细胞增殖的影响(英文)

目的　研究降钙素基因相关肽 (CGRP)对体外培养的糖尿病大鼠血管平滑肌细胞 (VSMC)增殖的影响。方法　用酶标仪和流式细胞仪检测不同浓度CGRP(1 ,1 0 ,1 0 0nmol·L-1 )对糖尿病大鼠VSMC的增殖的影响。结果　CGRP呈浓度和时间依赖性的抑制糖尿病大鼠VSMC增殖 ,格列本脲 (1 μmol·L-1 )部分阻断CGRP(1 0nmol·L-1 )对培养的糖尿病组VSMC的抗增殖作用 ,使其对VSMC的抑制率由(49 .3± 1 .2 ) %减至 (35 .6± 1 .1 ) % ,吡那地尔 (1μmol·L-1 )可增强其抗增殖作用 ,使其对VSMC的抑制率由 (49.3± 1 .2 ) %增至 (58.3± 3 .9) %。CGRP(1 0nmol·L-1 )可使停留于G0 /G1 细胞增多 ,进入S期和G2 /M期的细胞数目减少 ,吡那地尔 (1 μmol·L-1 )能增强其作用。结论　CGRP对糖尿病大鼠VSMC具有显著的抗增殖作用 ,使处于G0 /G1 期细胞增多 ,S和G2 /M期细胞减少。     

Oxidative stress and COX cause hyper-responsiveness in vascular smooth muscle of the femoral artery from diabetic rats

BACKGROUND AND PURPOSE: To investigate the dysfunction of vascular smooth muscle in streptozotocin-induced diabetic rats. EXPERIMENTAL APPROACH: Rings without endothelium of femoral arteries were suspended in organ chambers for isometric tension recording. The production of oxygen-derived free radicals was measured with 2',7'-dichlorodihydrofluorescein diacetate using confocal microscopy. The protein expressions were measured by western blotting. KEY RESULTS: The concentration-response curves to U46619 and phenylephrine, but not that to KCl, were shifted to the left, suggesting a hypersensitivity of cell membrane receptors in diabetes. Exogenous oxygen-derived free radicals induced greater vasoconstrictions in the femoral artery from diabetic rats. Chronic treatment with apocynin (inhibitor of NADPH oxidase) and acute exposure to MnTMPyP (SOD/catalase mimetic) normalized the response. The catalase activity and the total glutathione level were reduced in arteries from streptozotocin-treated rats, confirming a redox abnormality. The basal oxidative state was higher in arteries from streptozotocin-treated rats and reduced in arteries from apocynin- and streptozotocin-treated rats, suggesting that the functional changes in diabetes are due to a chronic increase in oxidative stress. In the arteries of streptozotocin-treated rats, inhibitors of COX-1 and/or COX-2 prevented the hypersensitivity and reduced the increase in oxidative stress caused by phenylephrine and U46619, suggesting that both isoforms contribute to the smooth muscle dysfunction. The expression of proteins for COX-1 and COX-2 was increased in arteries of streptozotocin-treated rats and reduced in preparations of apocynin- and streptozotocin-treated rats. CONCLUSIONS AND IMPLICATIONS: Chronic diabetes and the resulting increased oxidative stress activate the production of COX-derived vasoconstrictor prostanoids causing hypersensitivity of vascular smooth muscle.     

Role of K(+) channels in the coronary and renal vascular reactivity to vasopressin in diabetic rats

To study the role of K(+) channels in the coronary and renal vascular response to vasopressin during diabetes mellitus, and whether there are gender differences in this role, we have examined the isometric response to this peptide of 2-mm-long arterial segments from male and female, normoglycemic and streptozotocin-induced diabetic rats. Vasopressin (10(-12)-3 x 10(-8) M) produced arterial concentration-dependent contraction, and during normoglycemia, this contraction was lower in coronary arteries from female than from male rats, and it was similar in renal arteries from both genders. This contraction was reduced by diabetes in coronary arteries, and increased in renal arteries, from both genders. The blocker of Ca(2+)-sensitive K(+) channels charybdotoxin (10(-7) M) increased the contraction to vasopressin in coronary arteries of diabetic females, but not in the other cases (diabetic males and normoglycemic females or males). This blocker also increased the contraction to vasopressin in renal arteries from diabetic, but not in those from normoglycemic female rats, and also increased it in a higher magnitude in arteries from diabetic than in those from normoglycemic male rats. The blocker of ATP-sensitive K(+) channels glybenclamide (10(-5) M) or the scavenger of superoxide radicals superoxide dismutase (100 U/ml) did not modify the contraction to vasopressin in any experimental group. These results suggest that diabetes activates the modulatory role of K(+) channels in the coronary and renal vasoconstriction to vasopressin, but it alters in a different way the vasoconstriction to vasopressin in these two types of arteries. The effects of diabetes on this vasoconstriction are not related to increased release of superoxide radicals.     

Hypoxic pulmonary vasoconstriction is lacking in rats with type 1 diabetes

Hypoxic pulmonary vasoconstriction (HPV) is the most important feature of intact lung circulation that matches local blood perfusion to ventilation. The main goal of this work was to study the effects of diabetes on the development of HPV in rats. The experimental design comprised diabetes mellitus induction by streptozotocin, video‐morphometric measurements of the lumen area of intrapulmonary arteries (iPAs) using perfused lung tissue slices and patch‐clamp techniques. It was shown that iPA lumen size was significantly reduced under physical and chemical hypoxia (7–10 mm Hg) in normal iPA, but, on the contrary, it clearly increased in diabetic lung slices. The amplitude of the outward K⁺ current in diabetic iPAs smooth muscle cells (SMCs) was two‐fold greater than that seen in healthy cells. Chemical hypoxia led to significant decrease in the amplitude of the K⁺ outward current in healthy iPA SMCs while it was without effect in diabetic cells. The data obtained clearly indicate a significant dysregulation of vascular tone in pulmonary circulation under diabetes, ie diabetes damages the adaptive mechanism for regulating blood flow from poorly ventilated to better ventilated regions of the lung under hypoxia. This effect could be clinically important for patients with diabetes who have acute or chronic lung diseases associated with the lack of blood oxygenation.