血根碱对大鼠离体子宫平滑肌收缩的影响及其机制研究

试验旨在研究血根碱对大鼠离体子宫平滑肌活动的影响。分离8周龄SD雌性未孕大鼠子宫平滑肌,通过BL-420F生物信号采集系统记录子宫平滑肌收缩频率和收缩幅度,计算子宫平滑肌活力。以硫酸阿托品、盐酸普萘洛尔、盐酸苯海拉明及盐酸雷尼替丁为阻断剂,观察血根碱对子宫平滑肌M、β、H₁、H₂受体的关系,探讨血根碱对子宫平滑肌的作用机制。结果显示,血根碱组和元胡止痛片组对缩宫素所致大鼠离体子宫平滑肌收缩频率、收缩幅度和活力均有显著的抑制作用（P<0.05）;应用H₁受体阻断剂苯海拉明和H₂受体阻断剂雷尼替丁后,血根碱对子宫平滑肌抑制作用基本被阻断,而应用M受体阻断剂阿托品,β受体阻断剂普萘洛尔后,血根碱对子宫平滑肌收缩仍具有显著的抑制作用（P<0.05）。综上所述,血根碱对大鼠子宫平滑肌活力具有显著的抑制作用,可能是通过抑制H₁、H₂受体实现,与M、β受体无关。     

胆酸对气管平滑肌收缩及气管组织中cAMP含量的影响研究

采和气管容积法、气管螺旋条法和竞争性蛋白质结构分析法,研究了鸡胆汗有效成分胆酸（CA）对组织胺（His）和5－羟色胺（5－HT）所引起的豚鼠离体气管平滑肌收缩的影响,以及对大鼠气管组织中cAMP含量的影响。结果证明,CA对His引起的豚鼠离体完整气管平滑肌的收缩,以及His和5－HT引起的豚鼠离体气管螺旋条件平滑肌的收缩,均有很强的抑制作用;并能明显地提高大鼠气管组织中cAMP含量。     

紫菀乙醇提取物对豚鼠离体气管平滑肌收缩功能的影响

本试验旨在研究紫菀乙醇提物对豚鼠离体气管平滑肌收缩功能的影响。采用离体气管恒温灌流的方法,将豚鼠气管制成气管螺旋条,通过 BL-420F 生物机能实验系统测定其张力的变化,观察紫菀乙醇提物对离体气管平滑肌静息状态下的舒张作用,以及在氯化乙酰胆碱(Ach)、磷酸组胺(His)、CaCl₂条件下和无钙下Ach诱导细胞内钙释放和外钙内流所致两种收缩条件下对离体气管平滑肌张力变化的影响。试验结果显示,低浓度紫菀乙醇提取物(0.002~0.008 g/mL)对静息状态下豚鼠离体气管平滑肌具有一定的收缩作用,高浓度(0.008~0.196 g/mL)时具有舒张作用;低、中、高3个剂量组均可抑制Ach、His和CaCl₂引起的气管平滑肌收缩强度,使各致痉剂的量效曲线非平行右移并降低最大效应。紫菀乙醇提取物对His的抑制作用强度最大,其次为Ach,最后是CaCl₂,且均呈剂量依赖性。以上结果表明紫菀乙醇提物具有舒张气管平滑肌的作用,其机制可能与抑制豚鼠气管平滑肌M受体、H₁受体和阻断Ca²⁺通道从而抑制细胞Ca²⁺内流有关。     

正确使用催产素治疗母猪难产

催产素形成于丘脑下部的室旁核,并且呈滴状沿丘脑下部--垂体后叶径中的轴突运送到垂体后叶贮存.在分娩过程中,由于来自子宫和产道的刺激,可导致催产素的释出.催产素有兴奋子宫平滑肌,引起子宫收缩从而发生分娩作用.当母猪因体内催产素含量较低,子宫收缩微弱而引起难产时,可用催产素催产. 1.催产素对子宫的收缩作用以临产及刚分娩后较为敏感,无分娩预兆时催产无效. 2.由骨盆狭窄、产道受阻、胎位不正等引起的难产或有剖宫产史的母畜禁用,否则可能因子宫剧烈收缩而发生破裂死亡. 3.猪胎盘属于弥散型胎盘,胎儿胎盘和母体胎盘的联系不紧密.子宫的强烈收缩容易使二者引起分离.如果胎儿不能很快产出,就可能缺氧死亡.在临床上常可见到使用催产素治疗难产时产出死胎较多.所以催产素使用剂量要适宜.一般每次20～40IU,根据子宫收缩及胎儿排出情况可以考虑间隔2～3h重复使用1次.     

苦豆子植株不同部位醇提液对大鼠离体小肠运动的影响

为比较秋季苦豆子植株不同部位提取物对消化道运动的干预作用,本研究利用生物信号处理系统测定了浓度递增(0.5%~8.0%)的苦豆子植株不同部位(豆子、豆荚、叶和顶须)醇提液对大鼠离体小肠平滑肌运动的影响,并初步探究其机理。结果显示,与用药前相比,苦豆子植株各部位均在浓度递增到2.0%~4.0%时使离体小肠收缩频率和幅度减小(P<0.05),并呈剂量依赖关系,而对收缩张力影响不显著(P>0.05),其中豆子抑制作用最强。同时,胆碱能M-受体激动剂氯贝胆碱引起的小肠平滑肌兴奋作用可被2.0%豆子完全抑制,且2.0%豆子的抑制作用不能被氯贝胆碱扭转。结果表明,苦豆子植株各部位对离体小肠运动均有抑制作用,且可能与阻断M-受体作用有关。提示苦豆子植株各部位有望用于缓解由于某些原因引起的胃肠活动过度症状。     

益母草水煎剂对家兔离体子宫运动性能的影响

采用离体器官实验法 ,将不同状态下的家兔离体子宫置于恒温通气麦氏浴皿培养液中 ,向麦氏浴皿中逐次加入等量不同浓度的益母草水煎剂。通过 BL - New Century生物信号采集处理系统 ,扫描记录子宫平滑肌张力变化情况 ,观察益母草水煎剂对家兔离体子宫运动性能的影响 ,并探讨其作用机理。结果 :益母草水煎剂在浓度为 0 .2 5～ 1.0 0 g/ ml时 ,子宫平滑肌张力随浓度增大而增大 ;益母草水煎剂对怀孕家兔离体子宫的平滑肌收缩作用比空怀家兔离体子宫的平滑肌收缩作用显著 (P<0 .0 1) ,对怀孕家兔经己烯雌酚处理的离体子宫的平滑肌收缩作用比未经己烯雌酚处理的离体子宫平滑肌收缩作用显著 (P<0 .0 1) ;而对空怀家兔是否经己烯雌酚处理时的子宫平滑肌收缩作用差异不显著 (P<0 .0 5 )。结论 :益母草水煎剂对不同状态下的家兔离体子宫平滑肌收缩均有增强作用。     

催产素在母猪生产中的正确使用方法

催产素是一种特殊结构的环状肽类激素,有兴奋子宫平滑肌,引起子宫收缩,从而促进分娩的作用。当母猪由于体内催产素的含量较低、子宫收缩微     

柠檬酸和醋酸对小鼠离体肠平滑肌运动的影响

[目的]探究柠檬酸和醋酸对小鼠离体肠平滑肌运动的影响及可能的机制,为开发具有调控人或动物消化道运动机能障碍的有机酸类产品提供参考。[方法]用生物信号处理系统监测2倍浓度递增柠檬酸（0.02～0.64 mmol/L）或醋酸（0.13～2.00 mmol/L）及其一次性有效浓度对小鼠离体肠段收缩幅度、收缩张力及峰值的影响。[结果]柠檬酸和醋酸均剂量依赖性地减小肠平滑肌的收缩幅度和收缩张力（P<0.01）,其有效抑制浓度分别为0.32 mmol/L和1.00 mmol/L。有效抑制浓度的柠檬酸和醋酸均不影响25 mmol/L KCl引起的小肠收缩峰值（P>0.05）,但柠檬酸处理后显著（P<0.05）缓解M-受体激动剂氯贝胆碱引起的肠收缩幅度减小。[结论]柠檬酸和醋酸对小鼠离体肠平滑肌运动均具有抑制作用,且可能并不影响平滑肌细胞膜的去极化过程,但柠檬酸可能通过部分影响M-受体的作用而对消化道平滑肌具有解痉作用。     

催产素在奶牛生产中的应用

催产素是兽医产科的常用药。具有促使子宫及其他平滑肌收缩的功能。临床上常用的催产素是人工合成制剂．主要用于原发性子宫收缩无力所致难产的助产。根据其作用机理，还有多种用途，现综述如下。     

缩宫素在养猪临床上的合理应用

缩宫素俗称催产素,是一种能选择性地兴奋子宫,加强子宫平滑肌收缩的药物。用药的剂量不同,能使子宫产生节律性收缩或强直性收缩。如果用量适当,子宫节律性收缩加强,促使胎儿迅     

Effect of Sanguinarine on Active Capacity of Isolated Rat Uterine Smooth Muscle in vitro and Its Mechanism

The study was aimed to explore the effects of the sanguinarine on activity of isolated rat uterine smooth muscle in vitro. The effect of the sanguinarine on activity of the isolated myometrium of non-pregnant Sprague-Dawley rats eight weeks old was recorded by BL-420F four channels physiological recorder. Four antagonists, atropine sulfate, ranitidine hydrochloride, propranolol hydrochloride and diphenhydramine hydrochloride were used to study their mechanism, respectively. The results showed that sanguinarine and Yuan hu painkillers markedly inhibited the frequency, amplitude and activity of uterine contractions induced by oxytocin injection (P<0.05). The inhibitory effect of sanguinarine on uterine muscle contractions was blocked after using diphenhydramine hydrochloride (H₁-receptor antagonist) and ranitidine hydrochloride (H₂-receptor antagonist). However, after using atropine sulfate (M-receptor antagonist) and propranolol hydrochloride (β-receptor antagonist), sanguinarine also significantly inhibited the contractions of rat uterine smooth muscle (P<0.05). It was concluded that the effect of sanguinarine on activity of uterine smooth muscle in rats was mainly associated with H₁ receptor or H₂ receptor but not M receptor or β receptor.     

Effects of Alcohol Extract of Aster tataricus L.f.on the Contraction of Guinea Pig Tracheal Smooth Muscle in vitro

The aim of the experiment was to study the effect of alcohol extract of Aster tataricus L.f.on the contraction of isolated guinea pig tracheal smooth muscle.The guinea pig tracheal smooth muscle was prepared by isolated tracheal thermostatic perfusion method.The effects of Aster tataricus L.f.on tracheal smooth muscle under the resting state and contraction stimulated by acetylcholine (Ach),histamine (His),CaCl₂,Ca²⁺ release and influx in cells without calcium were measured by BL-420F biological function experiment systems.The results showed that Aster tataricus L.f.could induce the contraction of isolated trachea at resting state at a low concentrations of 0.002 to 0.008 g/mL and exerted a relaxation on the isolated trachea when at the higher concentrations of 0.008 to 0.196 g/mL.All of the three concentrations of Aster tataricus L.f.could inhibit the tension stimulated by Ach,His and CaCl₂ which were antispasmodic agents,led to the non-parallelled rightward moving of cumulative concentration-response curve and the decline of maximal responses.The suppressive effect on His was the strongest,followed by Ach and CaCl₂,and the suppression could counteract the contraction induced by extracellular Ca²⁺influx significantly,and they were all expressed concentration-dependent manner.These results indicated the alcohol extract of Aster tataricus L.f.could relax tracheal smooth muscle by acting on M-receptor and histamine receptor and blocking Ca²⁺ passage,thus inhibiting extracellular Ca²⁺influx.     

Die Bedeutung von Prostaglandin E2 in der Steuerung der Kontraktionen des Uterus: 1. Mitteilung: In-vitro Untersuchungen am Myometrium des Schweines

1. Prostaglandin E₂stimulates uterine smooth muscle of the pig in estrus to regular contractions with high amplitudes and a low tone. The threshold-dose is in the order of 1–10 ng PGE₂/ml bath. 2. In contrast to the short-time stimulation of the myometrium by oxytocin (3 I.mU.i ml bath) is the stimulation by PGE₂ of long duration. 3. Higher concentrations of PGE₂ in the organbath (1 μg PGE₂ml) temporarily inhibit the regular contractions, depending on the dose. This inhibition is blocked by propranolol (1 μg/ml bath). 4. The stimulation of the myometrium by PGE₂ is not influenced by phentolamin (I μg/ml bath). 5. The regular contractions caused by PGE₂ are abolished by indomethacin (100 μg/ ml bath). This inhibition can be neutralized by addition of PGE₂ to the organ bath. 6. Spontaneous motility of uterine smooth muscle is generated by an increase in tension. Indomethacin (100 μg/ml bath) inhibits this spontaneous motility. 7. In vitro uterine smooth muscles of the pig are probably stimulated by PGE₂ through an increase in the biosynthesis of prostaglandins.     

Effect of oxytocin, prostaglandin F2 alpha and reproductive tract manipulations on uterine contractility in Holstein cows on days 0 and 7 of the estrous cycle

The influence of various treatments on cattle at the time of natural estrus vs estrus induced by prostaglandin F2 alpha (PGF2 alpha) or at d 7 of the estrous cycle were studied; the latter is when embryo transfer often is performed. Eight lactating and 25 nonlactating, normal cycling cows were tested many times while in estrus and 7 d after estrus. A balloon was positioned in the body of the uterus to record changes in intrauterine pressure following clitoral massage, cervical massage, vaginal distention, electrical stimulation of the cervix and vagina, tailhead rubbing, udder massage and the injection of oxytocin or PGF2 alpha. Blood oxytocin and intramammary pressure were measured. There were no differences between cows in estrus spontaneously or those induced, so these groups were combined. Intravenous oxytocin injections of .5, 1, 2, 4 and 15 IU increased blood levels of oxytocin. Intramammary pressure was increased by all oxytocin doses, but greater than or equal to 2 IU were required to cause substantial changes in uterine contractions. As expected, the peak contractions during control periods for cows in estrus were high, averaging 31 mm Hg vs 11 mm Hg on d 7. None of the manipulations of the reproductive organs caused detectable oxytocin release or increases in intramammary pressure, contrasting to responses to massage of the udder. Clitoral massage increased peak uterine pressure by 32 to 60% in four experiments. It did not induce luteinizing hormone release. The contraction was immediate, was not sustained and could be obtained repeatedly, suggesting a reflex response. Treatment with PGF2 alpha increased intramammary pressure. It increased uterine pressure on d 7, but had no effect at estrus. This contrasts with injected oxytocin, which resulted in the highest amplitude for cows in estrus, although the response on d 7 was greater in proportion to the low activity in controls at that time. It is concluded that manual manipulation of the reproductive tract (other than clitoral massage) has little effect on uterine contractility.     

Age-related changes in contractions of chicken aorta and ischiadic artery

The characteristics of the contraction of vascular smooth muscle were examined in thoracic aorta and ischiadic artery of chickens aged 3, 6, 10 and 18 weeks. High K⁺ solution induced a sustained contraction in smooth muscle preparations of aorta and ischiadic artery in vitro . The contraction of the ischiadic artery became greater with age, whereas the contraction of the aortic preparation did not. In the ischiadic artery, the magnitude of the contraction divided by the weight of the muscle preparation was constant at all ages studied. However, those in the aortic preparation decreased with age. These results suggest that the changes in the contractile responses of vascular smooth muscle owing to the age of chickens vary widely according to the preparations of blood vessels, and that the functional smooth muscle cells in the thoracic aorta of chicken do not increase with age.     

电刺激发情期大鼠蓝斑核对子宫平滑肌电活动的影响

在急性实验条件下,以爆发波(BW)的频率、波宽、峰电位频率为指标,观察了电刺激蓝斑核对发情期大鼠子宫平滑肌电活动的影响.结果:电刺激蓝斑核后,子宫角平滑肌BW频率增加极显著,波宽及峰电位频率虽有增加,但无显著差异;子宫颈平滑肌BW频率无显著增加,波宽却显著缩短,峰电位频率有所减少,未见明显差异.结果表明,蓝斑核对发情期大鼠子宫平滑肌电活动具有调节作用.     

羊角拗苷对钉螺活动抑制试验

为了解羊角拗苷对钉螺足肌收缩活动的影响,采用PCLAB-UE生物医学信号采集处理系统测定离体平滑肌收缩频率,观察不同浓度的羊角拗苷对钉螺足肌收缩活动的影响。结果显示,羊角拗苷对钉螺足肌收缩频率的减慢与空白对照组比较具有显著性差异（P〈0.05）,先用羊角拗苷后再用新斯的明和阿托品刺激其足肌,其收缩变化无显著差异（P〉0.05）。说明羊角拗苷对钉螺的活动具有抑制作用。     

Tamoxifen induces vasorelaxation via inhibition of mitogen-activated protein kinase in rat aortic smooth muscle

The contribution of the mitogen-activated protein kinase (MAPK) pathway to the relaxation induced by tamoxifen, a synthetic non-steroidal anti-estrogen, was examined in rat vascular smooth muscle. Tamoxifen (0.1-300 microM) inhibited the contraction induced by endothelin-1 (ET-1, 3 nM) in aortic smooth muscle in a concentration-dependent manner. The inhibitory effect of tamoxifen was not attenuated by 10 microM ICI 182,780, a selective antagonist of estrogen receptors. In the Ca(2+) channel inhibitor verapamil (1 microM)-pretreated strips, tamoxifen also inhibited the contraction induced by ET-1. Both PD098059 and SB203580, inhibitors of MAPK/extracellular signal-regulated kinase (ERK) kinase and p38 MAPK, respectively, inhibited ET-1-induced contraction in aortic smooth muscle. In Western blot analysis with anti-phosphorylated MAPK antibodies, ET-1 (3 nM) enhanced activities of both ERK1/2 and p38 MAPK in aortic muscle strips, which were not attenuated by the treatment with 4 mM EGTA. Tamoxifen (100 microM) inhibited the activities of ERK1/2 and p38 MAPK induced by ET-1 without significant changes in the expression of these kinases. These results suggest that tamoxifen induces relaxation of rat vascular smooth muscle, and that this is, at least in part, mediated by the inhibition of the Ca(2+)-independent MAPK pathway.