Efectsofmoxonidineinjectedintorostralventrolateralmedulaonbloodpressure,heartrate,andrenalsympatheticnerveactivityinrats

目的：观察延髓腹外侧头端（ＲＶＬＭ）注射莫索尼定（Ｍｏｘ）对麻醉大鼠血压（ＢＰ）、心率（ＨＲ）及肾交感神经放电（ＲＳＮＡ）的影响．方法：麻醉大鼠ＲＶＬＭ注射１μＬＭｏｘ１，１０，１００μｍｏｌ·Ｌ－１，同步记录ＢＰ，ＨＲ及ＲＳＮＡ．结果：Ｍｏｘ１，１０，１００μｍｏｌ·Ｌ－１分别使ＢＰ从１３９±１０ｋＰａ降至１３０±１７ｋＰａ（Ｐ＜００５），１３８±１８ｋＰａ至１１４±１５ｋＰａ（Ｐ＜００１），ａｎｄ１３９±１９ｋＰａ至９４±１７ｋＰａ（Ｐ＜００１）．Ｍｏｘ不影响ＨＲ．Ｍｏｘ１μｍｏｌ·Ｌ－１增加ＲＳＮＡ５０％（Ｐ＜００５），１０μｍｏｌ·Ｌ－１对ＲＳＮＡ无影响（Ｐ＞００５），１００μｍｏｌ·Ｌ－１则降低ＲＳＮＡ２３％（Ｐ＜００５）．在缓冲神经切断大鼠，Ｍｏｘ１０μｍｏｌ·Ｌ－１抑制ＲＳＮＡ５０％（Ｐ＜００５），明显不同于缓冲神经完整的动物（Ｐ＜００１）．结论：麻醉大鼠ＲＶＬＭ注射Ｍｏｘ可降低ＢＰ，但不影响ＨＲ，且ＲＳＮＡ变化与其降压作用并不平行     

美西律对海马脑片突触功能缺氧损伤的保护作用

记录大鼠海马脑片ＣＡ１区锥体细胞的群锋电位（ＰＳ）和突触前排放（ＰＶ），缺氧３ｍｉｎ时对照组ＰＳ幅度下降至０．４±０．４ｍＶ，而提前１ｈ灌流美西律（Ｍｅｘ）１０或１００μｍｏｌ·Ｌ＾－１组ＰＳ仅下降至１．２±１．２或１．５±０．４ｍＶ。复氧３０ｍｉｎ后对照组ＰＳ恢复率为１１％，Ｍｅｘ１０或１００μｍｏｌ·Ｌ＾－１组分别为４８％和６５％。可见Ｍｅｘ减慢缺氧时ＰＳ下降过程，加速度复氧时ＰＳ恢复过程，…     

自发性高血压大鼠血小板神经肽Y释放增多

比较自发性高血压大鼠（ＳＨＲ）和ＷＫＲ大鼠血浆和血小板中神经肽Ｙ（ＮＰＹ）的含量，以及ＡＤＰ、凝血酶和胶原引起血小板聚集和ＮＰＹ释放的差别。方法：应用放射免疫分析法测定血小板及血浆ＮＰＹ听含量。结果：ＳＨＲ和ＷＫＲ大鼠血浆ＮＰＹ含量无明显差别，分别为２．１±１．０和１．８±１．０μｇ．Ｌ＾－１，而ＳＨＲ血小板ＮＰＹ含量（３２±６μｇ．Ｌ＾－１）显高于ＷＫＹ大鼠（２２±９μｇ．Ｌ＾－１）。凝血酶和     

糖尿病大鼠血中内源性一氧化氮合酶抑制物增高

目的：测定糖尿病大鼠血中内源性ＮＯ合酶抑制物二甲基精氨酸（ＤＭＡ）的含量，方法：在链佐星诱发的糖尿病大鼠测定血清ＤＭＡ的含量和乙酰胆碱（ＡＣｈ）诱导血管内皮依赖性舒张，结果：与对照组相比，糖尿病大鼠ＤＭＡ血清浓度显增加（５．４±１．０ｖｓ０．７±０．３μｍｏｌ．Ｌ＾－１，Ｐ〈０．０１）；丙二醛含量也高于对照组（２．５±０．３ｖｓ２１．５±０．１μｍｏｌ．Ｌ＾－１，Ｐ〈０．０１）；糖尿病大鼠ＡＣｈ     

兔蓝斑兴奋引起动脉血压升高

目的：研究电刺激和化学刺激兔蓝斑（ＬＣ）对动脉血压（ＡＰ）和肾交感神经传出活动（ＲＳＡ）的影响。方法：电刺激ＬＣ，ＬＣ微量注射Ｌ－Ｇｌｕ、盐酸吗啡、ＧＡＢＡ、电解毁损ＬＣ，记录ＡＰ和ＲＳＡ。结果：电刺激ＬＣ和ＬＣ注射Ｌ－Ｇｌｕ均引起ＡＰ升高分别为１３．５±０．３ｖｓ１９．５±０．８ｋＰａ和１３．８±０．４ｖｓ１７．５±０．８ｋＰａ）和ＲＳＡ增加。ＬＣ注射吗啡、ＧＡＢＡ对ＡＰ和ＲＳＡ无明显影响。电解     

小檗碱对豚鼠心室肌细胞L—及T—型钙离子通道的影响

目的：研究小檗碱（Ｂｅｒ）对心室肌细胞钙通道的影响。方法：全细胞膜片箝技术，结果：Ｂｅｒ（１０，３０μｍｏｌ．Ｌ＾－１）使豚鼠心室细胞Ｌ－型钙流由１４００±２４７ｐＡ分别减至９７８±２０４ｐＡ及６１７±２３ｐＡ（ｎ＝５，Ｐ〈０．０５），抑制效应呈浓度依赖及非频率依赖，其电流－电压曲线的峰值下降，Ｂｅｒ（１０μｍｏｌ．Ｌ＾－１）使Ｌ－型钙流失活曲线的最大半激活电压由－２７．８ｍＶ变为－３４．２ｍＶ，     

络活喜治疗慢性肾功能不全31例临床观察

用氨氯地平（络活喜）对３１例慢性肾功能不全伴高血压患者进行为期３个月的临床观察，治疗后血尿素氮（ＢＵＮ）、血肌酐（Ｓｃｒ）水平明显下降（１６．１±５．３ｖｓ１３．２±６．２ｍｍｏｌ／Ｌ，Ｐ〈０．０５；２５８±６２ｖｓ２２１±８２ｍｍｏｌ／Ｌ，Ｐ〈０．０５）；收缩压和舒张压明显减低（２２．６±０．９ｖｓ９．３±１．６ｋＰａ，Ｐ〈０．０１；１２．７±０．５ｖｓ１０．６±０．８ｋＰａ，Ｐ〈０．０１），同     

EDRF对NE引起的大鼠主动脉缩血管效应的作用

目的：研究ＥＤＲＦ（ｅｎｄｏｔｈｅｌｉｕｍ－ｄｅｒｉｖｅｄｒｅｌａｘｉｎｇｆａｃｔｏｒ，ＥＤＲＦ）对ＮＥ（ｎｏｒｅｐｉｎｅｐｈｒｉｎｅ，ＮＥ）引起的大鼠主动脉收缩反应的影响。方法：内皮完整和去内皮的大鼠主动脉环悬挂在器官浴槽中，测定血管的张力和收缩速度的变化。所有的实验在吲哚美辛（ｉｎｄｏｍｅｔｈａｃｉｎ，１０μｍｏｌ·Ｌ－１）和普萘洛尔（ｐｒｏｐｒａｎｏｌｏｌ，３μｍｏｌ·Ｌ－１）存在下进行。结果：用甲烯蓝（ｍｅｔｈｙｌｅｎｅｂｌｕｅ，ＭＢ，１０μｍｏｌ·Ｌ－１）和左旋硝基精氨酸（ＮＧ－ｎｉｔｒｏ－Ｌ－ａｒｇｉｎｉｎｅ，Ｌ－ＮＮＡ，３０μｍｏｌ·Ｌ－１）处理内皮完整的大鼠主动脉环，ＮＥ的剂量－收缩曲线明显左移。ＥＣ３０值均降低７倍，最大反应比值分别为１．６±０．３和１．７±０．４。在去内皮的大鼠主动脉环中，经ＭＢ与Ｌ－ＮＮＡ处理后，仍可见ＥＣ３０下降３倍，最大反应比值分别为１．１±０．６和１．１±０．４。后者可能与血管平滑肌产生少量ＥＤＲＦ有关。结论：结果提示，ＮＥ对血管的收缩反应也受血管内皮和平滑肌产生的ＥＤＲＦ的调控。     

粉防己碱对大鼠脑细胞内游离钙的影响

利用荧光钙指示剂Ｆｕｒａ－２／ＡＭ，测定脑细胞内游离钙的浓度，细胞内静息钙浓度为２２１±１８ｎｍｏｌ·Ｌ＾－１。Ｔｅｔ３０μｍｏｌ·Ｌ＾－１对细胞内静息钙无影响。Ｔｅｔ（１－１００μｍｏｌ·Ｌ＾－１）能抑制胞外高钾引起的胞内钙升高，其ＩＣ５０为８．２（９５％可信限为１．８９－３２．９０μｍｏｌ·Ｌ＾－１）。Ｔｅｔ３０μｍｏｌ·Ｌ＾－１可抑制去甲肾上腺素１０μｍｏｌ·Ｌ＾－１引起细胞内钙升高，其幅…     

硝苯地平控释片对无痛性心肌缺血病人左心功能的影响

目的：观察硝苯地平控释片（Ｎｉｆ－ＣＲ）治疗无痛性心肌缺血（ＳＭＩ）时对左心功能的影响。方法：３６例ＳＭＩ病人（男性２３例，女性１３例；年龄５６±ｓ７ａ）采用Ｎｉｆ－ＣＲ２０ｍｇ，ｐｏ，ｑ１２ｈ×３ｗｋ。结果：（１）舒张压从１２５±２．３ｋＰａ下降至９．７±２．３ｋＰａ（Ｐ＜０．０５）；缺血型ＳＴ段压低明显改善（从１．６±０．７ｍｍ升至１．０±０．６ｍｍ）（Ｐ＜０．０１）。（２）核素心功能检测，ＬＶＥＦ，ＳＶ，ＥＲ，ＰＦＲ及ＲＣＯ均显著改善（Ｐ＜０．０５或Ｐ＜０．０１）。（３）治疗后ＰＲＡ和ＡＮＧⅡ水平降低（Ｐ＜０．０５）。结论：Ｎｉｆ－ＣＲ的持久血药浓度可改善左心功能，降低血压。不良反应小。     

莫索尼定对去缓冲神经大鼠延髓腹外侧头端神经元自发电活动的影响

在去缓冲神经大鼠观察莫索尼定对延髓腹外侧头端区 (RVLM) 神经元自发电活动的影响. 向颈总动脉内注射莫索尼定2, 10, 50 μg·kg^-1后, 同步记录神经元放电图,血压及心率. 结果显示,莫索尼定剂量依赖性地降低RVLM 神经元放电率,血压和心率. 莫索尼定10, 50 μg·kg^-1使放电率分别减少23% 和41%. 动脉注射选择性I₁-咪唑啉受体阻断剂依法克生10 μg·kg^-1, 可完全拮抗莫索尼定10 μg·kg^-1 的作用. 结果提示, 莫索尼定通过激动延髓腹外侧头端区神经元上的I₁-咪唑啉受体,抑制其自发放电活动.     

重组人内皮细胞衍生的白细胞介素—8对大鼠失血性休克的作用

目的：研究重组人内皮细胞衍生的白细胞介素－８（ＩＬ－８）对失血性休克的作用。方法：大鼠肌动脉放血至ＭＡＢＰ５．３２ｋＰａ，维持９０ｍｉｎ，复制晚期失血性休克模型。输血后，静脉注射ＩＬ－８ ２５０μｇ·ｋｇ＾－１。放免法测定血浆ＥＴ－１和６－ＫＰＧＦ１α含量。结果：给予ＩＬ－８周，ＭＡＢＰ显提高，休克状态改善，２ｈ存活率相应提高；休克晚期血浆ＥＴ－１水平比正常明显升高（２１±４ｖｓ８．２±１．８ｎ     

雌二醇抑制豚鼠心室肌细胞内向整流和延迟整流钾通道电流

研究雌二醇对心室肌细胞动作电位,内向整流钾通道电流及延迟整流钾通道电流的影响。方法：全细胞膜片箝技术。结果：ＥＳＴ１０μｍｏｌ．Ｌ＾－１使豚鼠心室肌细胞ＡＰ时程明显缩短,ＡＰＤ５０由给药前（４７４±７１）ｍｓ缩短至（３３０±７５）ｍｓ（Ｐ〈０．０５）,Ｅｓｔ１００μｍｏｌ．Ｌ＾－１使ＡＰＤ５０缩短至（２２９±６７）ｍｓ,ＡＰＤ９０由（５８７±６０）ｍｓ缩短至（４１８±７９）ｍｓ,Ｅｓｔ浓度依赖性地     

Comparison of angiotensin II-induced blood pressure and structural changes in Fischer 344 and Wistar Kyoto rats

1. The purpose of the present study was to evaluate the blood pressure (BP) response, the BP and heart rate (HR) components of the startle reaction and the structure of the carotid artery and the aorta during chronic infusion of angiotensin (Ang) II in Fischer 344 (F344) compared with Wistar Kyoto (WKY) rats, two in-bred normotensive contrasted strains. 2. Osmotic mini-pumps filled with saline vehicle or AngII (120 ng/kg per min) were implanted subcutaneously in 8-week-old normotensive rats and infused for 4 weeks in F344 rats (saline, n = 10; AngII, n = 10) and WKY rats (saline, n = 10; AngII, n = 9). Basal BP, HR and the responses to an acoustic startle stimulus (duration 0.7 s, 115 dB) were recorded in conscious rats. The structure of the carotid artery and aorta was determined in 4% formaldehyde-fixed arteries. 3. Compared with WKY rats, vehicle-treated F344 rats had lower bodyweight (BW; 266 +/- 7 vs 299 +/- 9 g; P < 0.05) and heart weight (0.80 +/- 0.02 vs 0.98 +/- 0.04 g; P < 0.05) and higher aortic systolic BP (SBP; 131 +/- 1 vs 123 +/- 5 mmHg; P < 0.001) and diastolic BP (98 +/- 3 vs 89 +/- 2 mmHg; P < 0.001). In F344 rats, compared with the WKY rats, the wall thickness/BW ratio was increased in the carotid artery (156 +/- 9 vs 131 +/- 6 nm/g; P < 0.05) and abdominal aorta (264 +/- 13 vs 217 +/- 12 nm/g; P < 0.05) and decreased in the thoracic aorta (246 +/- 13 vs 275 +/- 8 nm/g; P < 0.05). There was no difference in elastin and collagen density. Angiotensin II differentially enhanced BP in both strains: (SBP: 163 +/- 5 and 132 +/- 4 mmHg in F344 and WKY rats, respectively; P(strain x treatment) < 0.05). Circumferential wall stress was increased in the aorta of F344 rats compared with WKY rats (1176 +/- 39 vs 956 +/- 12 kPa (P < 0.001) and 1107 +/- 42 vs 813 +/- 12 kPa (P < 0.001) in thoracic and abdominal aortas, respectively). The startle response was amplified in F344 rats, with enhanced increases in SBP and pulse pressure (PP) and bradycardia compared with responses of WKY rats (+44 +/- 9 mmHg, +10 +/- 2 mmHg and -40 +/- 17 b.p.m., respectively, in F344 rats vs+28 +/- 4 mmHg, + 4 +/- 2 mmHg and -19 +/- 10 b.p.m. in WKY rats, respectively; P(strain) < 0.05 for BP and PP). The startle response was not affected by AngII. 4. These results indicate a higher BP producing an increase in wall thickness in F344 rats compared with WKY rats. We propose that an increase in sympathetic nervous activity causes these haemodynamic differences, as suggested by the excessive increase in BP during an acoustic startle stimulus. Angiotensin II increased BP in F344 rats, but did not exaggerate the increase in BP during the startle reaction.     

Sympathoinhibitory effects of rilmenidine may be mediated by sites located below the brainstem.

1. To determine the site of action of rilmenidine, we examined its effets on arterial blood pressure (BP), heart rate (HR) and postganglionic renal sympathetic nerve activity (RSNA) after intracerebroventricular (i.c.v.) administration (300 micrograms kg-1), in groups (all n = 6) of conscious and freely moving, pentobarbitone-anaesthetized and pentobarbitone-anaesthetized and spinally transected, fifteen week-old male spontaneously hypertensive rats (SHRs). 2. In conscious SHRs, which exhibited a low sympathetic nerve activity (RSNA: 3.4 +/- 0.9 muV), rilmenidine was inactive on systolic BP (SBP), diastolic BP (DBP), HR and RSNA. 3. In intact pentobarbitone-anaesthetized SHRs, which exhibited an elevated sympathetic nerve activity (RSNA: 10.6 +/- 0.9 muV), rilmenidine exerted potent antihypertensive (delta SBP: -37 +/- 4%; delta DBP: -43 +/- 6%), bradycardic (delta HR: -32 +/- 3%) and sympathoinhibitory (delta RSNA: -68 +/- 9%) activities. 4. In pentobarbitone-anaesthetized SHRs with cervical spinal cord transection, BP was markedly decreased and sympathetic nerve activity (RSNA: 10.3 +/- 3.1 muV) returned to the level observed in conscious SHRs (RSNA: 3.6 +/- 0.5 muV). In these conditions, rilmenidine remained sympathoinhibitory (delta RSNA: -74 +/- 5%). 5. In conclusion, we have shown that pentobarbitone-anaesthesia enhances the peripheral sympathetic tone by a central action, as the spinal cord transection allows RSNA to return to normal levels and that, spinal or ganglionic structures could be a major site of the sympathoinhibitory action of rilmenidine.     

Effects of berbamine on ATP-induced [Ca2+]i mobilization in cultured vascular smooth muscle cells and cardiomyocytes.

AIM: To study the effects of berbamine (Ber) on [Ca2+]i homeostasis induced by adenosine triphosphate (ATP) in vascular smooth muscle cells (VSMC) of rabbits and cardiomyocytes of rats. METHODS: Both cell types were cultured and loaded with Fura 3-AM. [Ca2+]i was measured by fluorescent intensity (FI) in each cell with confocal microscopy. RESULTS: (1) ATP 30 mumol.L-1 elevated [Ca2+]i in VSMC and cardiomyocytes, FI values reached 660 +/- 258 and 1058 +/- 252 from 250 +/- 84 and 218 +/- 76 at 19 s +/- 5 s and 11.8 s +/- 2.4 s, but FI in nucleus was not changed in VSMC. (2) Ber 30 mumol.L-1 did not affect the resting FI in both cell types, but prolonged the time to peak (P < 0.01) and reduced the FI elevated by ATP (P < 0.01), but not completely inhibited even at 100 mumol.L-1. (3) In D-Hanks' solution or in the presence of egtazic acid (EGTA) 3 mmol.L-1, the inhibitory effect of Ber was not seen (P > 0.05). (4) All effects of Ber on ATP-induced [Ca2+]i mobilization were similar to those of Ver 10 mumol.L-1. CONCLUSION: In VSMC and cardiomyocytes, ATP-induced CA2+ influx was inhibited by Ber and Ver, while the Ca2+ release was not.     

氯沙坦通过室旁核抑制慢性心衰大鼠肾交感神经兴奋性

目的：研究慢性心衰时室旁核微量注射氯沙坦对心率、血压和肾交感神经的作用,揭示心衰下丘脑室旁核对肾交感神经活性的调节机制。方法：用SD大鼠制作心衰模型,超声心动图检测心功能变化。脑立体定位仪对大鼠室旁核定位,微量注射氯沙坦（50nL）,观察心率、血压和肾交感神经活性的变化。结果：超声心动图显示手术组较假手术组左室内径增加（P〈0．01）,射血分数降低（P〈0．01）,左室内径缩短率降低（P〈0．05）。注射氯沙坦后,手术组和假手术组的肾交感神经兴奋性降低,手术组较假手术组降低更为明显。结论：心衰时室旁核内注射氯沙坦可降低肾交感神经兴奋性。     

Low dose of moxonidine within the rostral rentrolateral medulla improves the baroreflex ;ensitivity control of sympathetic activity in hypertensive rat

Aim:

To determine the effects of the centrally antihypertensive drug moxonidine injected into the rostral ventrolateral medulla (RVLM) on baroreflex function in spontaneously hypertensive rats (SHR).

Methods:

Baroreflex sensitivity control of renal sympathetic nerve activity (RSNA) and barosensitivity of the RVLM presympathetic neurons were determined following application of different doses of moxonidine within the RVLM.

Results:

Three doses (0.05, 0.5, and 5 nmol in 50 nL) of moxonidine injected bilaterally into the RVLM dose-dependently reduced the baseline blood pressure (BP) and RSNA in SHR. At the highest dose (5 nmol) of moxonidine injection, the maximum gain (1.24%±0.04%/mmHg) of baroreflex control of RSNA was significantly decreased. However, the lower doses (0.05 and 0.5 nmol) of moxonidine injection into the RVLM significantly enhanced the baroreflex gain (2.34%±0.08% and 2.01%±0.07%/mmHg). The moxonidine-induced enhancement in baroreflex function was completely prevented by the imidazoline receptor antagonist efaroxan but not by the α₂-adrenoceptor antagonist yohimbine. A total of 48 presympathetic neurons were recorded extracellularly in the RVLM of SHR. Iontophoresis of applied moxonidine (30–60 nA) dose-dependently decreased the discharge of RVLM presympathetic neurons but also significantly increased the barosensitivity of RVLM presympathetic neurons.

Conclusion:

These data demonstrate that a low dose of moxonidine within the RVLM has a beneficial effect on improving the baroreflex function in SHR via an imidazoline receptor-dependent mechanism.     

硝普盐、3-吗啉-悉尼酮亚胺和精胺对豚鼠胃窦环行肌钙敏感钾电流的影响(英文)

目的:探讨一氧化氮对豚鼠胃窦环行肌钙敏感钾电流的影响。方法:采用全细胞式的膜片箝方法,用精胺、硝普盐、3-吗啉-悉尼酮亚胺(SIN-1)作为一氧化氮供体。结果:外向钾电流被四乙铵(1 mmol·L~(-1))和ChTx(200nmol·L-1)显著抑制。在穿孔膜式条件下,精胺(100 μmol·L~(-1))、SIN-1(200 μmol·L~(-1))、硝普盐(100 μmol·L~(-1))均增加钙敏感钾电流。1μmol·L~(-1)亚甲蓝完全阻断硝普盐与SIN-1导致的增加效应。结论:一氧化氮增加豚鼠胃窦环行肌钙敏感钾电流,该效应可能通过环磷酸鸟苷介导。     

酚妥拉明对豚鼠心室肌细胞L型钙电流及ATP敏感钾电流的抑制作用

目的：研究酚妥拉明对豚鼠凡肌细胞Ｌ－型钙电流及ＡＴＰ敏感钾电流的作用。方法：用膜片钳的全细胞记录方式观察钙电流和ＡＴＰ敏感钾电流。结果：酚妥拉明５，２５和１００μｍｏｌ·Ｌ＾－１对钙电流呈浓度依赖性和非电压依赖性的抑制作用，抑制率分别为１７％，２３％和３０％，而对电流－电压关系没有影响。这一抑制作用与酚妥拉明对α１和α２受体的作用无关。酚妥拉明１００μｍｏｌ·Ｌ＾－１可显著抑制ＤＮＰ诱导产生的ＡＴ