Local anesthetic action of phentolamine on insect mechanoreceptors

1. The effect of phentolamine on the response properties of insect mechanoreceptors and on the conduction in their axons was examined using electrophysiological techniques. 2. Phentolamine blocked conduction of action potentials along axons, an effect which exhibited 3 characteristics typical of local anesthetics: the effect was frequency-dependent, reversible and varied for nerves with different diameters. 3. The concentration of phentolamine required to block axonal conduction (1-2 x 10(-3) M) was significantly higher than that required to abolish the response of receptors to mechanical stimulation (3-5 x 10(-4) M). 4. All mechanoreceptors that were examined in Locusta migratoria and Periplaneta americana were inactivated by phentolamine (Table 1). The type I receptors (chordotonal, campaniform and hair sensilla) were inactivated within 5-15 min following phentolamine application. The only type II receptor examined (forewing stretch-receptor) underwent a phase of repetitive discharge before being inactivated. 5. Tolazoline and metoclopramide inactivated, like phentolamine, mechanoreceptors at lower concentrations than necessary to block axonal conduction. However, yohimbine and chlorpromazine inactivated mechanoreceptors and blocked axonal conduction at similar concentrations. 6. These findings suggest that phentolamine affects sense-organ specific ionic processes that are more sensitive to the drug than the ionic processes along the axons.     

酚妥拉明联合多巴酚丁胺与多巴胺治疗重症肺炎患儿的有效性及安全性分析

目的:分析和比较酚妥拉明联合多巴酚丁胺与多巴胺治疗重症肺炎患儿的有效性及安全性。方法:选取2014年4月至2019年4月西安交通大学附属儿童医院急诊科收治的96例重症肺炎患儿,根据入院单双号将其分为对照组(n=48)和研究组(n=48)。对照组接受多巴酚丁胺与小剂量多巴胺治疗,研究组在对照组的基础上联合酚妥拉明治疗。比较两组的治疗总有效率、治疗前后各血气指标与炎性因子水平变化以及不良反应的发生情况。结果:治疗后,研究组总有效率显著高于对照组(93.75%vs.79.17%,P0.05);两组的血气指标PaO2、SaO2均显著升高,PaCO2显著降低,且研究组的变化比对照更加显著(P0.05);两组各的炎性因子水平IL-6、IL-8、CRP和TNF-α均显著降低,且研究组显著低于对照组(P0.05)。两组不良反应发生率比较无统计学差异(P0.05)。结论:酚妥拉明联合多巴酚丁胺治疗重症肺炎患儿的临床疗效明显优于酚妥拉明联合多巴胺治疗,且二者安全性相当。     

Blood pressure responses of conscious rats to intravenous administration of enkephalin derivatives (D-ala methionine and leucine enkephalinamide, and methionine and leucine enkephalinamide)

The present study was designed to determine the blood pressure (BP) responses of conscious rats given intravenous (IV) injections of enkephalin derivatives (D-ala²-methionine enkephalinamide, DAMEA; D-ala²-leucine enkephalinamide, DALEA; methionine enkephalinamide, MEA; leucine enkephalinamide, LEA) and the receptor mechanisms mediating the resultant change in BP. IV injection of 1.6–16.0 nmoles of DAMEA or DALEA caused a transient but potent decrease in mean arterial pressure (MAP) and mean heart rate (MHR). LEA and MEA (16.0 nmoles) given IV produced slight pressor responses, which were not associated with concomitant tachycardia whereas 48 nmoles of MEA elicited a hypotensive effect accompanied by a fall in MHR. Pretreatment studies whereby various receptor antagonists (naloxone, diprenorphine, phentolamine, D-L-propranolol or atropine) were given IV 5 min before subsequent IV administration of DAMEA, DALEA, MEA or LEA (16 nmoles) showed that naloxone, diprenorphine and atropine blocked the depressor and bradycardic effects of DALEA and DAMEA. Naloxone and phentolamine suppressed the pressor reponse of both MEA and LEA (16.0 nmoles) while diprenorphine blocked the rise in MAP to only MEA. The results show that DAMEA and DALEA mediate their depressor actions in conscious rats via a negative chronotropic effect through an interaction of muscarinic cholinergic receptors on the myocardium. It is suggested that the pressor response of MEA and LEA may be produced via an -receptor mediated effect on the peripheral vasculature to cause vasoconstriction.     

酚妥拉明联合银杏达莫治疗慢性肺源性心脏病疗效观察

目的:观察酚妥拉明联合银杏达莫对慢性肺源性心脏病心衰患者的疗效,为临床治疗提供依据。方法:将90例患者随机分为治疗组和对照组各45例。两组采用常规内科治疗如控制感染、氧疗、强心、利尿等,治疗组在上述治疗基础上加用酚妥拉明20mg+银杏达莫25 mL于10%葡萄糖注射液500 mL中静脉滴注,1次/d,疗程均为10 d。结果:治疗组的疗效、血气分析、血液流变学、功能的改善优于对照组,差异具有统计学意义(P<0.05)。结论:酚妥拉明联合银杏达莫对慢性肺源性心脏病心衰患者具有良好的疗效及安全性,值得临床推广应用。     

酚妥拉明、多巴胺联合心肺复苏对心搏骤停患者的影响

目的:研究酚妥拉明、多巴胺联合心肺复苏对心搏骤停患者的影响。方法:选择2015年2月至2016年4月在我院进行治疗的心搏骤停患者60名,按照治疗方法的不同分为观察组和对照组,对照组使用常规方法治疗,观察组在对照组基础上联合酚妥拉明及多巴胺治疗。观察和比较两组治疗后的临床疗效、生存情况、血清cTnI、CK、CK-MB、MDA、SOD水平和血流动力学参数的变化。结果:治疗后,观察组总病死率20%,明显低于对照组33.33%(P0.05)。观察组心肺复苏后0.5-1h血清c Tn I水平显著高于对照组(P0.05),2-24 h血清cTnI水平显著低于对照组(P0.05);观察组心肺复苏后各时点血清CK、CK-MB水平均显著低于对照组(P0.05);观察组复苏后24 h的MDA、SOD浓度较对照组[(1.86±1.65)μg/L vs(3.81±1.24)μg/L、(6.58±0.95)μg/L vs(3.74±0.56)μg/L](P0.05)。心肺复苏后,观察组患者从第2 h开始MAP值明显高于对照组水平(P0.05);观察组患者CO值及CI值从第6h开始明显升高显著高于对照组水平(P0.05);且观察组患者PCWP值各时段均显著低于对照组(P0.05)。结论:酚妥拉明联合多巴胺用于治疗心搏骤停患者可明显减轻患者心肌损伤,改善其血流动力学及患者预后,提高生存率,且安全性高。     

Effects of haloperidol and phentolamine on the crustacean cardiac ganglion

Haloperidol (a dopamine D₂ blocker in vertebrates) and phentolamine (an α-adrenergic blocker) alter the pattern of bursting by the isolated cardiac ganglion of the lobster when perfused at concentrations of 10^?6–10^?5 mol/l. Both drugs decrease the frequency of bursting and increase burst duration. They are most effective in slowing the ganglion when applied selectively to the anterior ganglionic trunk, the same region of the ganglion where dopamine (DA) and 5-hydroxytryptamine (5HT) are most effective in speeding up bursting. When exogenous monoamine transmitters are applied in the presence of 3×10^?6 mol/l haloperidol, the effect of 5HT, but not of DA, is significantly reduced. At the same concentration, phentolamine does not suppress the actions of DA, 5HT or noradrenaline (NA). Both haloperidol and phentolamine significantly alter the properties of endogenous burst-organizing potentials (driver potentials) generated by motorneurons in the ganglion. It is possible that the effects of these drugs on bursting reflect alteration of endogenous electrical properties of the constituent neurons, rather than receptor antagonism.     

酚妥拉明联合亚胺培南西司他丁钠对重症肺炎患儿肺功能、炎性因子及血清sTREM-1、sICAM-1水平的影响

目的:研究酚妥拉明联合亚胺培南西司他丁钠对重症肺炎患儿肺功能、炎性因子以及血清可溶性髓系细胞触发受体-1(sTREM-1)、可溶性细胞间黏附分子-1(sICAM-1)水平的影响。方法:选择2018年9月至2019年10月在我院治疗的80例重症肺炎患儿,随机分为对照组(40例)和研究组(40例)。对照组给予静滴亚胺培南西司他丁钠,研究组在对照组基础上静滴酚妥拉明注射液。比较两组患儿临床疗效,对比两组患儿退热时间、肺啰音和咳嗽消失时间及住院时间,比较两组患儿治疗前后肺功能变化情况,测定并比较两组患儿治疗前后血清炎性因子水平变化及血清sTREM-1、sICAM-1水平变化。结果:研究组总有效率(92.50%)明显高于对照组(75.00%),差异具有统计学意义(P0.05);研究组退热时间、肺啰音及咳嗽消失时间和住院时间与对照组相比,均明显减少(P0.05);治疗后,研究组的动脉血氧分压(P_aO_2)和动脉/肺泡氧分压比值(a/APO_2)较对照组明显升高,二氧化碳分压(P_aO_2)较对照组明显降低(P0.05);治疗后,研究组血清白细胞介素(IL)-6、IL-8和C反应蛋白(CRP)及血清中sTREM-1、sICAM-1水平较对照组显著降低(P0.05)。结论:酚妥拉明联合亚胺培南西司他丁钠治疗重症肺炎患儿,可以明显提高肺功能,降低炎性因子水平,降低血清中sTREM-1和sICAM-1水平,促进症状好转,提高疗效,减少住院时间。     

多巴胺联合酚妥拉明治疗小儿重症肺炎合并心衰疗效研究

目的:探讨多巴胺联合酚妥拉明治疗小儿重症肺炎合并心力衰竭疗效及心肌酶学变化情况。方法:选择2014年10月至2015年3月之间于我院进行治疗的重症肺炎合并心力衰竭患儿185例作为研究对象随机分组。对照组92例患儿给予常规综合治疗,观察组93例患儿在此基础上给予多巴胺联合酚妥拉明治疗。比较两组患儿临床疗效、症状改善时间、治疗前后生命体征及心肌酶学指标变化情况以及不良反应发生情况。结果:观察组显效率及总有效率显著高于对照组,症状改善时间显著短于对照组,差异有统计学意义(P0.05)。治疗前两组患儿生命体征及心肌酶学各项指标均无显著差异(P0.05),治疗后两组患儿呼吸频率(HR)、心率(RR)显著下降,血氧饱和度(SpO_2)显著升高,心肌酶学各项指标均显著下降,差异较治疗前均有统计学意义(P0.05)。组间比较,观察组患儿治疗后生命体征及心肌酶学各指标均明显优于对照组,差异有统计学意义(P0.05)。两组患儿不良反应发生率无明显差异(P0.05)。结论:多巴酚联合酚妥拉明治疗小儿重症肺炎合并心力衰竭具有良好的临床疗效及安全性,利于患儿临床症状及心肌损伤的恢复,值得临床推广应用。     

三种方案治疗小儿重症肺炎的临床效果及安全性比较

目的:比较三种方案治疗小儿重症肺炎的临床效果及安全性。方法:选取我院于2012年1月~2016年1月收治的120例重症肺炎患儿,按照不同的治疗方法随机分为观察组1(多巴胺联合多巴酚丁胺)42例,观察组2(多巴胺联合酚妥拉明)40例及对照组38例。比较三组患者临床疗效及炎症因子水平的变化。结果:观察组1的总有效率为90.48%,观察组2的总有效率为87.5%,均显著高于对照组的总有效率(63.16%)。观察组(1、2)的肺啰音消失时间、咳嗽症状消失时间、呼吸困难改善时间、退热时间以及住院天数均显著短于对照组(p0.05)。治疗后,三组患者的血清白介素6(IL-6)、白介素8(IL-8)、C反应蛋白(CRP)以及肿瘤坏死因子(TNF-α)的水平与治疗前相比均显著降低,差异均具有统计学意义(p0.05),且观察组患者以上指标的水平均显著低于对照组(p0.05)。结论:多巴胺联合多巴酚丁胺和多巴胺联合酚妥拉明治疗小儿重症肺炎的疗效和安全性相当,二者均明显优于常规治疗。     

Octopamine--a single modulator with double action on the heart of two insect species (Apis mellifera macedonica and Bactrocera oleae): Acceleration vs. inhibition

The effects of octopamine, the main cardioacceleratory transmitter in insects, were investigated, in the isolated hearts of the honeybee, Apis mellifera macedonica, and the olive fruit fly, Bactrocera oleae. Octopamine induced a biphasic effect on the frequency and force of cardiac contractions acting as an agonist, with a strong acceleratory effect, at concentrations higher than 10⁻¹² M for the honeybee and higher than 50 × 10⁻⁹ M for the olive fruit fly. The heart of the honeybee is far more sensitive than the heart of olive fruit fly. This unusual sensitivity is extended to the blockers of octopaminergic receptors, where phentolamine at 10⁻⁵ M stopped the spontaneous contractions of the honeybee heart completely and permanently, while the same blocker at the same concentration caused only 50% inhibition in the heart of the olive fruit fly. Phentolamine and mianserin at low concentrations of 10⁻⁷ M also blocked the heart octopaminergic receptors, but for a short period of time, of less than 15.0 min, while a partial recovery in heart contraction started in spite of the presence of the antagonist. The unusual response of the honeybee heart in the presence of phentolamine and/or mianserin suggests excitatory effects of octopamine via two different receptor subtypes. At lower concentrations, 10⁻¹⁴ M, the agonist octopamine was converted to an antagonist, inducing a hyperpolarization in the membrane potential of the honeybee cardiac pacemaker cells and inhibiting the firing rate of the heart. The inhibitory effects of octopamine on certain parameters of the rhythmic bursts of the heart of the honeybee, were similar to those of mianserin and phentolamine, typical blockers of octopaminergic receptors. The heart of the olive fruit fly was 10⁵ times less sensitive to octopamine, since a persistent inhibition of heart contractions occurred at 10⁻⁹ M. In conclusion, the acceleration of the insect heart is achieved by increasing the levels of octopamine, while there is a passive but also an active decrease in heart activity due to the minimization of octopamine.