Epinephrine Hydrochloride Research Articles

Effect of Acute Versus Continuous Glycemic Control on Duration of Local Anesthetic Sciatic Nerve Block in Diabetic Rats

The duration of nerve block is longer in streptozotocin (STZ)-induced diabetic rats for all local anesthetics (with and without adjuvants) compared with normal rats. Perioperative glycemic control is currently practiced to reduce adverse events in many at-risk patients, especially in diabetic patients, to prevent neuropathy, poor wound healing, and greater incidence of infection. The aim of this study was to investigate in diabetic rats the importance of glycemic control before peripheral nerve block. To induce diabetes, rats were intravenously injected with a single dose of 50 mg/kg STZ to destroy pancreatic beta cells. Tactile allodynia in response to von Frey filament stimulation of the plantar hind paws was used as the criterion for diabetic neuropathy. Diabetic rats were randomly divided into experimental treatment groups. The continuous glycemic control experiment compared: 3 U/d insulin implant for 14 days, 1.5 U/d insulin implant for 14 days, and placebo treatment. The acute glycemic control experiment compared a single 6U Human Insulin Isophane Suspension (NPH) injection and placebo treatment. Nondiabetic rats received placebo implants or injections. Following treatment, 0.1 mL of 1% lidocaine hydrochloride with 5 μg/mL epinephrine hydrochloride was injected into the left sciatic notch. Animals were then reevaluated at 10-minute intervals for the absence or presence of sensory and motor response. All STZ-injected rats had blood glucose levels greater than 350 mg/dL and tactile allodynia. After insulin implants or injections, diabetic rats had much lower blood glucose levels than diabetic rats with placebo treatment. With both 3 and 1.5 U/d continuous glycemic control, the local anesthetic solution produced a shorter duration of sensory and motor nerve block in insulin-treated diabetic rats compared with placebo-treated diabetic rats, and shorter duration was similar to nondiabetic rats. With 6 U acute glycemic control in diabetic rats, there was no reduction in nerve block duration compared with placebo-treated diabetic rats. With continuous glycemic control in diabetic rats, the duration of sensory and motor nerve block was about 40 minutes shorter than that in the untreated diabetic rats and similar to that of normal rats. However, acute glycemic control did not affect nerve block duration, suggesting that this neuropathy cannot be rapidly reversed.

Simultaneous determination of epinephrine and uric acid at ordered mesoporous carbon modified glassy carbon electrode

An ordered mesoporous carbon modified glassy carbon electrode was employed for the simultaneous determination of epinephrine and uric acid by differential pulse voltammetry. The modified electrode exhibited excellent electrocatalytic ability for the oxidation of epinephrine and uric acid, and two well-defined oxidation peaks towards two species with a potential difference of 170 mV appeared at the modified electrode. Under optimum conditions, linear responses of epinephrine and uric acid were obtained in the concentration ranges of 0.5 to 200 μM, and 0.25 to 100 μM, with detection limits of 0.2 μM and 0.07 μM (S/N = 3), respectively. The proposed modified electrode displayed high selectivity, good stability and reproducibility, and was successfully applied for the determination of epinephrine in epinephrine hydrochloride injection and uric acid in human urine samples.

Determination of epinephrine by the Briggs-Rauscher oscillating system using non-equilibrium stationary state

A highly sensitive method for the determination of epinephrine was proposed, which was based on the perturbation of epinephrine to Briggs-Rauscher oscillating system involving malonic acid, Mn2+, H+, IO3 - and H2O2 at non-equilibrium stationary state. The concentration of KIO3 was chosen as a control parameter to find the bifurcation point in this paper. Results showed that a well linear relationship between the difference of potential and the negative logarithm concentrations of epinephrine existed in the range of 1.1?10-7?5.2?10-9 mol L-1 with a lower detection limit of 6.8?10-10mol L-1 and a correlation coefficient of 0.9974. Compared to the classical oscillating reaction, this method has a lower detection limit and wider linear range. The effects of some foreign species, which may possibly be existed with epinephrine, on determination were also investigated. The proposed method has been successfully used to determine the epinephrine both in the serum and adrenaline hydrochloride injection.

Taoren–Honghua herb pair and its main components promoting blood circulation through influencing on hemorheology, plasma coagulation and platelet aggregation

Ethnopharmacological relevancePersicae Semen (Taoren) and Carthami Flos (Honghua) used in pair which is named as Taoren–Honghua (TH) herb pair has been used in traditional Chinese medicine (TCM) for promoting blood circulation to dissipate blood stasis for many years in China. Aim of the studyThis paper investigated the effects of TH and its main components amygdalin and hydroxysafflor yellow A (HSYA) on hemorheological disorders of blood stasis in rats. Materials and methodsRats were randomly divided into seven groups (control group, model group, TH group, amygdalin group, HSYA group, amygdalin+HSYA group, and aspirin group) with eight animals in each, whose gender was equally distributed throughout groups. All treatments were performed by gavage and administered seven times with an interval of 12h. After the fifth administration, the model rats except those in control group with blood stasis were established by being placed in ice-cold water during the interval between two injections of adrenaline hydrochloride (Adr); and blood samples were collected 30min after the last administration on the following day. ResultsTH could significantly decrease whole blood viscosity (WBV), plasma viscosity (PV) and packed cell volume (PCV). It also significantly prolonged thrombin time (TT) and thromboplastin time (APTT), increased prothrombin time (PT) and lowered fibrinogen content (FIB). HSYA which significantly decreased WBV and PV had no effect on plasma coagulation parameters. Amygdalin could significantly decrease PV, prolong APTT and decrease FIB, showing few effects on WBV. TH and its main components amygdalin and HSYA could significantly reduce platelet aggregation and protect vascular endothelial cells. Based on the above results, amygdalin and HSYA were responsible for the main curative effects of TH and usually had synergetic effects, such as decreasing PV and platelet aggregation percentage. ConclusionsThe study may provide scientific information to further understanding of the mechanism(s) of TH and its main components in activating blood circulation to dissipate blood. It may also create valuable insight into the possible effects and utilization of TH and its components as a feasible alternative therapeutic agent for patients with hemorheological disorders.

A novel nanocomposites sensor for epinephrine detection in the presence of uric acids and ascorbic acids

A novel nanocomposites film of conducting polymers including single-walled carbon nanotubes (SWCNTs), polypyrrole (PPy) and gold nanoparticles (AuNPs) modified electrode has been applied in voltammetric sensors to detect epinephrine (EP) sensitively when ascorbic acids (AA) and uric acids (UA) exist. The nanocomposites film of conducting polymers which show an excellent electrocatalystic activity for the oxidation of EP and UA was characterized by scanning electron microscopy (SEM) and electrochemical methods. The catalytic peak currents obtained from differential pulse voltammetry (DPV) increased linearly with increasing EP concentrations in the range of 4.0 × 10 −9–1.0 × 10 −7 M with a detection limit of 2.0 × 10 −9 M (S/N = 3), respectively. The results showed that the nanocomposites of conducting polymers can selectively determine EP in the coexistence of a large amount of UA and AA. In addition, the sensor exhibited excellent sensitivity, selectivity and stability. The PPy/AuNPs/SWCNTs nanocomposites film can also be satisfactorily used for detecting EP in epinephrine hydrochloride injection when contain AA and UA, which also shows good recovery for determination of EP in some biological fluids.

Gold nanoparticle/single-walled carbon nanotube film on the surface of glassy carbon electrode and its application

A sensor based on gold nanoparticle/single-walled carbon nanotube film on the surface of glassy carbon electrode is prepared. Electrochemical behavior of adrenaline hydrochloride (AH) on the surface of gold nanoparticle/single-walled carbon nanotube modified glassy carbon electrode is investigated. A simple, sensitive, and inexpensive method for determination of AH is proposed. The oxidation peak currents is proportional to adrenaline hydrochloride concentrations in the range of 0.20 mg L − 1 to 1.80 mg L − 1 in 0.1 M phosphate buffer solution of pH 7.3, the detection limit for AH is 0.06 mg L − 1 , and the recoveries are in the range from 100.0 to 110.0% with RSD of 1.2–1.9% (n = 6).

Study on Slice-based Biosensor for Electrophysiological Propagation Measurement in Drugs Screening

In order to investigate the signal propagation of the cardiac tissue and the action of drugs, we developed a slice- based biosensor to monitor the electrophysiological activities of the cardiac tissues. At first, we analyzed the interface model of the slice-based biosensor and the electrolyte, and observed the characteristics of the slice-based biosensor with tissue over time. Then, using the slice-based biosensor we sampled the beating signals of the cardiac slices respectively in the presence of the normal Tyrode’s solution, Adrenaline Hydrochloride and Acetylcholine chloride. Further, we used statistic analysis and correlation analysis to review the propagation of beating signals and the action of drugs on propagation. Results showed that the slice-based biosensor is apt and stable enough to catch the character and tendency of signal propagation and Delay is the key to deduce the conduction tendency. Adrenaline Hydrochloride and Acetylcholine chloride respectively have excitatory and inhibiting action on Amplitude and Frequency of the beating signals, and appear dependent on dosage. Thus, slice-based biosensor offers a noninvasive and versatile method to study the cardiac beating and the electrophysiological propagation for drugs screening. It is significative to guide clinical remedy of the drugs’ acting targets in the future.

The influence of pollen pellet on metabolic indices at experimental hyperglycemia

Pollen pellet is a complex of biologically active substances that caused its use in therapy of a number of diseases. The given work is devoted to the study of influence of pollen pellet on major indicators of metabolism at experimental hyperglycemia, caused by adrenalin hydrochloride or insulin deficiency caused by alloxan hydrochloride. Indices of carbohydrate, lipidic, protein-nucleic metabolism condition and process are defined in experiments on rats. It is established that disorders of metabolic indices on two models of hyperglycemia have rather similar picture and that normalizing action of pollen pellet causes the metabolic processes in organism tissues. In this connection the pollen can be applied in complex treatment of hyperglycemic conditions including diabetes mellitus.

Epinephrine hydrochloride prevents bone cement implantation syndrome in cemented hip replacement

Objective To investigate the clinical application of epinephrine hydrochloride in the prevention of bone cement implantation syndrome in the cemented hip replacement. Methods The clinical data of 48 patients treated with cemented hip replacement from July 2008 to April 2009 were retrospectively analyzed. All the patients were divided into control group and intervention group. The bone marrow cavities of 24 patients in the control group were not pretreated with saline epinephrine hydrochloride before implantation of bone cement; the bone marrow cavities of 24 patients in the intervention group were pretreated with saline epinephrine hydrochloride before implantation of bone cement. Systolic blood pressure （SBP）, diastolic blood pressure （DBP）, the mean arterial pressure （MAP）, heart rate （HR）and pulse oxygen saturation （ SPO2 ） were compared between the two groups before bone cement implantation and 1,2, 3, 4, 5, 6, 7, 8, 9, 10 minutes after bone cement implantation. The data were analyzed with variance analysis and Q test. Results （1） In the control group： the blood pressure was decreased in control group one minute after bone cement implantation and a significant decrease of the blood pressure was observed at 2-6 minutes after the implantation （ P 〈 0. 01 ）. The blood pressure was increased seven minutes after the implantation, with the most significant increase of DBP （ P 〈 0.05 ）.The blood pressure recovered to normal 10 minutes later. The SPO2 was decreased significantly （ P 〈0.05 ） but no significant change was observed in HR （ P 〉 0.05）. （2） In the intervention group： the bone marrow cavity was pretreated with saline epinephrine hydrochloride before implantation of bone cement.ity. No significant difference was found in SBP, DBP, MAP, HR and SPO2 at different time points before and after bone cement implantation （P 〉0.05 ）. Significant decrease of blood pressure and SPO2 was observed in control group and a significant hemodynamic change was detected at 2-6 minutes after the bone cement implantation. In the intervention group, no hemodynamic change was found in all the patients except that one patient was found with decrease of blood pressure and another one with the occasional premature ventricular contractions. Conclusion Pretreatment of bone marrow cavity with saline epinephrine hydrochloride can effectively prevent bone cement implantation syndrome. Key words: Arthroplasty, replacement, hip ; Epinephrine ; Bone cement implantation syndrome

Flow Injection With inhibited Chemiluminescence Method for the Determination of Adrenaline Hydrochloride

A simple rapid and accurate flow injection inhibitory chemiluminescence method has been developed for the determination of adrenaline hydrochloride based on its inhibition of the chemiluminescence from the luminol ،V potassium hexacyanoferrate (III) system. The linear range of determination is 8.0 „e 10-12 ،V 8.0 „e 10-10 mgl-1 for adrenaline hydrochloride and the detection limit is 4.0 „e 10-9 g ml-1. The method has been applied to determine the content of adrenaline in pharmaceutical preparation with satisfactory results.

Enhanced Voltammetric Detection of Epinephrine at a Carbon Nanotube/Nafion Composite Electrode in the Presence of Ascorbic Acid

Voltammetry has been shown to be especially useful to detect epinephrine in the nervous or pharmacological system. A major limitation of this strategy, however, is the interference of ascorbic acid, which is usually present in high concentration and can be oxidized at a potential close to that of epinephrine. Furthermore, the sensitivity is rather low. In order to get selective and sensitive measurements of epinephrine in the presence of ascorbic acid via electrochemical methods, we fabricated the CNT/Nafion composite electrode and investigated the electrocatalytic activity of the composite electrode toward epinephrine in this paper. Due to the high electrocatalytic activity of CNTs and the selective penetration of Nafion membrane, the composite electrode was found to enhance the oxidation peak current and lower the overpotential of epinephrine. In the complex sample medium, permeation of the positive charged epinephrine into the electrode surface was significantly facilitated, while that of neutral ascorbic acid (AA) moiety in the acidic solution was largely blocked. As a result, interference from the coexisted ascorbic acid was excluded at the CNT/Nafion composite electrode. Differential pulse voltammetry was successfully utilized for the determination of epinephrine in the presence of a large quantity of ascorbic acid. In the presence of 4.0 mM ascorbic acid, the anodic currents of epinephrine are linearly dependent on the concentrations of epinephrine in the range of 0.2 to 20 microM with the detection limit of 0.04 microM. The feasibility of the composite electrode for determination of epinephrine in adrenaline hydrochloride injection has also been demonstrated.

Radioimmunoimaging study of pulmonary artery thrombi in rabbits with 99Tcm-SZ-51 after bone cement perfusion and intervention.

Objective To detect pulmonary artery thrombosis with ^99Tc^m -SZ-51 in rabbits after cement perfusion, and to discuss the ways of preventing pulmonary artery thrombus. Methods Sixteen rabbits （weight 2.5-3.0 kg）were randomly divided into 4 groups： group A （no intervention group）, bone cement perfusion into madullary cavity and compression; group B （adrenalin hydrochloride group）, pretreat the madullary cavity with adrenalin hydrochloride （1：10 000）, and then bone cement perfusion and compression; group C （fibrin sealant group）, pretreat the madullary cavity with fibrin sealant, and then bone cement perfusion and compression; group D （control group）, no bone cement perfusion. ^99Tc^m -SZ-51 was injected through ear marginal vein for 2 ml before perfusing bone cement. The radioactivity of lung was measured in vivo af- ter perfusing 60,120 and 180 min. Then the rabbit were killed and its lung was harvested. The radioactivity was measured in vitro and the pathological examination was done. Results After perfusion 60, 120 and 180 min, the radioactivities of lung were （11.48＋2.35）, （14.41-＋3.10）, （18.25±5.01） ID/pixels in the group A, （8.21±3.21）, （10.19±2.40）, （11.32±3.12） ID/pixels in the group B, （4.06±1.04）, （5.68±2.80）, （7.40±1.12） ID/ pixels in the group C, respectively. The difference among groups was statistically significant. Pulmonary artery thrombus had been found in group A, B and C, but not in group D. Pretreatment with adrenalin hy- drochloride and fibrin sealant, the radioactivity of lung was significantly decreased. Conclusion ^99Tc^m -SZ-51 can be used in the observation of pulmonary artery thrombus formation after bone cement perfusion in rabbit. Pretreatment with adrenalin hydrochloride and fibrin sealant before bone cement peffusion can significantly lower the risk of pulmonary artery thrombus. Key words: Bone cements; Pulmonary embolism; Radioimmunodetection; Platelet activation ; Antibodies, monoclonal

Adrenaline-Induced Chronic Ocular Hypertension in Adult Rabbits

The aim of this study was to develop a new animal model to enhance our understanding of the biological pathomechanisms involved in glaucoma. Forty white giant rabbits were divided into a treated (N = 30) and a control group (N = 10). Boli of adrenaline hydrochloride (0.1 mL 0.1% solution) were repeatedly injected into the veins of the ears of the rabbits and physiological saline in the control group, respectively, for three months. Intraocular pressure (IOP) and outflow facility of the aqueous humour were measured prior to, during and after treatment (4-6 months, 7-9 months, 10-12 months). In comparison to the control group, the adrenaline-treated group showed a significant increase in IOP both during treatment (25%) and 12 months after treatment (57%). Comparative analysis further showed that the aqueous humour outflow facility of the treated group increased by 16.5% during the treatment, and showed a continuous decrease of 60 % after treatment. This rabbit model could be useful for further investigations of the pathomechanisms involved in glaucoma.

β2-Adrenoceptor affinity chromatography and its application in the screening of the active compounds from Semen Armeniacae Amarum

β2-Adrenoceptor (β2-AR) was purified from the rabbit lung tissue by sepharose-salbutamol affinity chromatographic column. To prepare the β2-AR stationary phase, β2-AR was evenly immobilized on the surface of macro-pore silica with a mild chemical coupling method through covalent bond. The retention properties of β2-AR stationary phase were characterized by four ligands, salbutamol sulfate, noradrenaline bitartrate, adrenaline hydrochloride and propranolol hydrochloride, to establish the β2-AR affinity chromatography. Then, the method was used to screen the active compounds from the total extracts of Semen Armeniacae Amarum. The results showed that β2-AR on the surface of the stationary phase could keep its original bioactivity and selectivity. Amygdalin retained in the chromatographic column was proved to be the active compound of the total extracts of Semen Armeniacae Amarum. Compared with the existing chromatographic screening approaches, this method showed a good stability and high selectivity. The active compounds which could interact with β2-AR in traditional Chinese medicine (TCM) could be screened efficiently by this method, providing a new way to screen the active compounds in complicated samples such as TCM.

Abstract 2012: Relationship Between Adrenaline Concentration and Postresuscitation Syndrome in Patients with Return of Spontaneous Circulation (ROSC) After Out-of-Hospital Cardiac Arrest

Background Although there is evidence that epinephrine hydrochloride favors initial ROSC, there is a paucity of evidence that it improves survival in humans. The value and safety of the Î 2 -adrenergic effects of epinephrine is controversial because they may lead to increase postresuscitation syndrome after ROSC. Few studies have investigated whether adrenaline concentration before epinephrine administration was related to incidence of postresuscitation syndrome. METHODS We did a prospective study of adult patients who achieved ROSC with standard cardiopulmonary resuscitation after out-of-hospital cardiac arrest. Blood samples to measure the adrenaline concentration were taken from a vein. The primary endpoint was neurological outcomes at hospital discharge. RESULTS Of the 274 adult patients with out-of-hospital cardiac arrest, 108(39%) achieved ROSC. The adrenaline levels ranged from 53 to 15,329pg/ml, with a median of 1,545pg/ml, and 25th and 75th percentile values of 707 and 4,486pg/ml, respectively. Of those, 71% (77/108) had an unfavorable neurological outcome and the adrenaline level was higher among such patients than among those with a favorable neurological outcome (a median, 2,016pg/ml vs. 938pg/ml, p=0.048). Moreover, the adrenaline level was higher among patients who died of postresuscitation syndrome within 24 hours of ROSC than among those with survival at 24 hours (a median, 3,290pg/ml vs. 1,343pg/ml, p=0.038). The adrenaline cutoff value of 944pg/ml for unfavorable neurological outcome had an accuracy of 70%. The adjusted odds ratio for the unfavorable neurological outcome after adrenaline cutoff value of 944pg/ml was 8.9 (95% CI, 2.2–35.9; p=0.002). On the other hand, the adrenaline level after epinephrine administration was 28 times as high as that before epinephrine administration (a median, 42,868pg/ml vs. 1,545pg/ml, p<0.0001). CONCLUSIONS In adult patients with ROSC after out-of-hospital cardiac arrest, adrenaline level before epinephrine administration was associated with incidence of postresuscitation syndrome, and the level was extremely increased after epinephrine administration. Epinephrine administration may lead to a severe toxic hyperadrenergic state in postresuscitation period.

End-column chemiluminescence detection for pressurized capillary electrochromatographic analysis of norepinephrine and epinephrine

A simple and convenient end-column chemiluminescence (CL) detection coupled to pressurized capillary electrochromatography (pCEC) was described. Luminol and N-(4-aminobutyl)- N-ethylisoluminol (ABEI) were adopted as mode compounds to evaluate the feasibility of end-column reactor. Detailed analysis of ABEI revealed that the high sensitivity could be obtained with the reactor. Furthermore, determination of norepinephrine (NE) and epinephrine (EP), which were labeled with ABEI, was accomplished by using the end-column pCEC–CL detection based on ABEI–potassium ferricyanide–alkaline medium CL reaction system. Under the optimum conditions, the detection limit (S/N = 3) of NE and EP was 0.08 μM and 0.06 μM, respectively. The proposed method has also been successfully applied to the analysis of adrenaline hydrochloride injection sample.

Electrodeposition of gold nanoclusters on overoxidized polypyrrole film modified glassy carbon electrode and its application for the simultaneous determination of epinephrine and uric acid under coexistence of ascorbic acid

A novel biosensor was fabricated by electrochemical deposition of gold nanoclusters on ultrathin overoxidized polypyrrole (PPyox) film, formed a nano-Au/PPyox composite on glassy carbon electrode (nano-Au/PPyox/GCE). The properties of the nanocomposite have been characterized by field emission scanning electron microscope (FE-SEM), X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD) and electrochemical investigations. The nano-Au/PPyox/GCE had strongly catalytic activity toward the oxidation of epinephrine (EP), uric acid (UA) and ascorbic acid (AA), and resolved the overlapping voltammetric response of EP, UA and AA into three well-defined peaks with a large anodic peak difference. The catalytic peak currents obtained from differential pulse voltammetry increased linearly with increasing EP and UA concentrations in the range of 3.0 × 10 −7 to 2.1 × 10 −5 M and 5.0 × 10 −8 to 2.8 × 10 −5 M with a detection limit of 3.0 × 10 −8 and 1.2 × 10 −8 M ( s/n = 3), respectively. The results showed that the modified electrode can selectively determine EP and UA in the coexistence of a large amount of AA. In addition, the sensor exhibited excellent sensitivity, selectivity and stability. The nano-Au/PPyox/GCE has been applied to determination of EP in epinephrine hydrochloride injection and UA in urine samples with satisfactory results.

Electrochemical Behavior of Epinephrine at Two‐Component Self‐Assembled Monolayer of meso‐2,3‐Dimercaptosuccinic Acid and Penicillamine on Gold Electrode

A mixed, self‐assembled monolayer (SAM) of meso‐2,3‐dimercaptosuccinic acid (DMSA) and penicillamine (PCA) was prepared on a gold electrode. The mixed SAM of DMSA and PCA, for which the volume ratio of DMSA:PCA was 2:1, showed an obvious electrochemical activity for the oxidation of epinephrine (EP). In the phosphate buffer (pH 7.7), a sensitive oxidation peak was observed at 0.213 V on the DMSA and PCA modified Au electrode. The peak current was proportional to the concentration of EP in the range between 5.0×10−6 and 8.0×10−4 mol L−1. For the cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods, the detection limits were 3.9×10−7 and 2.5×10−7 mol L−1, respectively. The reaction mechanism has been primarily discussed. The electrode reaction of EP was an irreversible process with two electrons and two protons transfer at the SAM gold electrode. The SAM gold electrode was applied to the determination of EP in epinephrine hydrochloride injection samples with satisfactory results.

Combined preoperative topical atropine sulfate 1% and intracameral nonpreserved epinephrine hydrochloride 1:2500 for management of intraoperative floppy-iris syndrome

We describe a technique combining preoperative atropine sulfate 1% and intraoperative intracameral epinephrine in a 1:2500 dilution for the management of intraoperative floppy-iris syndrome (IFIS) induced by alpha(1A)-blocking agents such as tamsulosin. Patients on alpha(1A)-blocking agents used topical atropine sulfate 1% 3 times a day for 2 days before surgery. In addition to routine topical mydriatics before surgery, they received intracameral epinephrine diluted 1:2500 with BSS. In 19 of 20 eyes, there were no clinical manifestations of IFIS with this regimen. Stimulation of the iris dilator by a direct-acting sympathomimetic (epinephrine) combined with strong pupiloplegia (atropine) provides powerful synergism. Preoperative identification of patients on alpha(1)-blockers is important as complications can be reduced significantly by using appropriate strategies to deal with this condition. It is also important that patients suffering from benign prostatic hyperplasia do not stop using an alpha(1A)-blocker, especially when preoperative atropine is used, as acute urinary retention may ensue.

Electrochemical Behavior of Epinephrine at a Meso‐2,3‐Dimercaptosuccinic Acid Self‐Assembled Gold Electrode and Its Analytical Application

Meso‐2,3‐dimercaptosuccinic acid (DMSA) can bind onto the surface of a gold electrode through the strong gold‐sulfur interaction. The formation mechanism and electrochemical properties of the DMSA monolayer were studied by electrochemical quartz crystal microbalance, complex impedance analysis, surface enhanced Raman spectroscopy, and cyclic voltammetry. The DMSA‐modified gold electrode shows an obvious electrocatalytic activity for the oxidation of epinephrine (EP). There are good linear relationships between peak current and the concentration of EP in the range of 8.0×10−6∼4.0×10−3 mol L−1 and 5.0×10−7∼6.0×10−3 mol L−1 for the cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods with the detection limits of 4.8×10−7 and 4.7×10−8 mol L−1, respectively. The reaction mechanism was primarily discussed. The electrode reaction of EP is an irreversible process with two electrons and two protons at the DMSA‐modified gold electrode. The modified electrode was applied to the determination of EP in epinephrine hydrochloride injection samples with satisfactory results. This project is supported by the Municipal Science Foundation of Chongqing City (No. CSTC‐2004BA4024) and the Doctor Foundation of Southwest China Normal University (2003‐10, 2003‐11), and all authors here express their deep thanks.