MRI diagnosis and differential diagnosis of mediastinal neuroganglionic tumors in children / 中国基层医药

Objective In order to improve the accuracy of preoperative diagnosis ,the value of MRI in the diagnosis and differential diagnosis of the mediastinal neuroganglionic tumors in children was explored .Methods A retrospective analysis of 41 cases of pathologically proven mediastinal neuroganglionic tumors [GN 19 cases,6 cases of ganglion neuroblastoma ( GNB), 16 cases of neuroblastoma ( NB)] was conducted.The MRI characteristics and clinicopathological features were analyzed , including age, size, shape and boundary of tumor , MRI plain scan and enhanced signal characteristics,compared with postoperative pathology.Results The average age of the 19 cases of GN was 3.9 years,the maximum diameter of the tumor was 7.3 cm,12 cases of tumor morphology ,18 cases of clear border,11 cases of tumor interlinking with vertebral canal ,0 case with multi nodular fusion ,12 cases with lengthwise tumor,11 cases with low signal in T1 WI,12 cases of uniform high signal in T 2 WI,and 2 cases with hemorrhagic necrotic cysts and cystic degeneration.In 6 cases of GNB and 16 cases of NB,the above －mentioned signs were 4.1 years old,1.9 years old,6.8 cm,6.4cm,2,6;5,12;3,15;2,10;3,12;0,4;3,9;2,11;1,2;5,9;0,7,there were statistically significant differences in age of onset (F＝4.145;P＝0.024),relationship between tumors and vertebral canal(P＝0.023),hemorrhagic necrosis and cystic degeneration (P＝0.001),multiple nodule fusion ( P＝0.000), plain T1 WI signal ( P ＝0.015 ), and associated metastasis ( P ＝0.000 ).There were no statistically significant differences in tumor size(F＝0.363;P＝0.698),tumor shape(P＝0.277),boundary(P＝0.221),lengthwise growth (P＝0.401),plain scan T2 WI signal( P＝0.835),intensifying degree (P＝0.338),whether the tumor had capsule (P＝0.423).Conclusion The onset age of benign GN is significantly larger than that of NB ,T1 WI plain scan is mostly low signal,after enhancement ,mainly with mild strengthening ,GNB and NB tumor shape is irregular ,NB is mainly multi nodular fusion ,which easy to occur hemorrhage and necrosis cystic change ,T2 WI is mainly mixed high signal,mostly moderate or clear uneven enhancement ,NB is prone to invasion of the spinal canal and distant metastasis.

A Report on Bilaterally Elongated Superior Cervical Ganglion

Superior cervical ganglion (SCG), the largest of the three cervical sympathetic ganglia, is formed by the fusion of first four cervical ganglia. Bilaterally elongated superior cervical ganglion was observed in a female cadaver during dissection. On the right side, it was 63.74 mm long and 5.75 mm wide and on the left side, it was 62.88 mm and 5.84 mm respectively. Histological analysis of the ganglion done with toluidine blue staining confirmed the structure of sympathetic ganglion. Superior cervical ganglion is the preferred ganglion for sympathetic block in conditions like trigeminal neuralgia, atypical facial pain,and post-herpetic neuralgia. Even though superior cervical ganglion has been reported to be at the safest location, thetension of sympathetic trunk while retracting the carotid sheath during surgeries might result in Horner’s syndrome. Furthermore, a large ganglion may also be confused with deep cervical lymph nodes or retropharyngeal mass during imaging studies. Understanding the variant anatomy of the superior cervical ganglion might serve as a guide for imaging studies, cervical spine surgeries,and sympathetic block.

High-resolution Imaging of Neural Anatomy and Pathology of the Neck

The neck has intricately connected neural structures, including cervical and brachial plexi, the sympathetic system, lower cranial nerves, and their branches. Except for brachial plexus, there has been little research regarding the normal imaging appearance or corresponding pathologies of neural structures in the neck. The development in imaging techniques with better spatial resolution and signal-to-noise ratio has made it possible to see many tiny nerves to predict complications related to image-guided procedures and to better assess treatment response, especially in the management of oncology patients. The purposes of this review is to present imaging-based anatomy of major nerves in the neck and explain their relevant clinical significance according to representative pathologies of regarded nerves in the neck.

Bile Acid Inhibition of N-type Calcium Channel Currents from Sympathetic Ganglion Neurons

Under some pathological conditions as bile flow obstruction or liver diseases with the enterohepatic circulation being disrupted, regurgitation of bile acids into the systemic circulation occurs and the plasma level of bile acids increases. Bile acids in circulation may affect the nervous system. We examined this possibility by studying the effects of bile acids on gating of neuronal (N)-type Ca2+ channel that is essential for neurotransmitter release at synapses of the peripheral and central nervous system. N-type Ca2+ channel currents were recorded from bullfrog sympathetic neuron under a cell-attached mode using 100 mM Ba2+ as a charge carrier. Cholic acid (CA, 10(-6) M) that is relatively hydrophilic thus less cytotoxic was included in the pipette solution. CA suppressed the open probability of N-type Ca2+ channel, which appeared to be due to an increase in null (no activity) sweeps. For example, the proportion of null sweep in the presence of CA was ~40% at +40 mV as compared with ~8% in the control recorded without CA. Other single channel properties including slope conductance, single channel current amplitude, open and shut times were not significantly affected by CA being present. The results suggest that CA could modulate N-type Ca2+ channel gating at a concentration as low as 10(-6) M. Bile acids have been shown to activate nonselective cation conductance and depolarize the cell membrane. Under pathological conditions with increased circulating bile acids, CA suppression of N-type Ca2+ channel function may be beneficial against overexcitation of the synapses.

Intravenous regional block is similar to sympathetic ganglion block for pain management in patients with complex regional pain syndrome type I

Sympathetic ganglion block (SGB) or intravenous regional block (IVRB) has been recommended for pain management in patients with complex regional pain syndrome type I (CRPS-I). Forty-five patients were initially selected but only 43 were accepted for the study. The present study evaluated the efficacy of IVRB produced by combining 70 mg lidocaine with 30 µg clonidine (14 patients, 1 male/13 females, age range: 27-50 years) versus SGB produced by the injection of 70 mg lidocaine alone (14 patients, 1 male/13 females, age range: 27-54 years) or combined with 30 µg clonidine (15 patients, 1 male/14 females, age range: 25-50 years) into the stellate ganglion for pain management in patients with upper extremity CRPS-I. Each procedure was repeated five times at 7-day intervals, and pain intensity and duration were measured using a visual analog scale immediately before each procedure. A progressive and significant reduction in pain scores and a significant increase in the duration of analgesia were observed in all groups following the first three blocks, but no further improvement was obtained following the last two blocks. Drowsiness, the most frequent side effect, and dry mouth occurred only in patients submitted to SGB with lidocaine combined with clonidine. The three methods were similar regarding changes in pain intensity and duration of analgesia. However, IVRB seems to be preferable to SGB due to its easier execution and lower risk of undesirable effects.

Gustatory Change after Sympathetic Ganglion Block in Complex Regional Pain Syndrome Type I Patient: A case report

Some reports provide conclusive evidence of close interactive regulation between the taste receptor and sympathetic nervous system. We report a middle-aged male patient with gustatory change after cervical sympathetic ganglion block (CSGB) who had been suffering from hypersensitivity to sour taste since developing complex regional pain syndrome (CRPS) type 1, diagnosed according to the revised CRPS criteria. Despite receiving two high doses of prednisolone therapy, he experienced the recurrence of CRPS symptoms. We attempted other therapy treatments, including pamidronate intravenous infusion, non-steroidal anti-inflammatory drugs, opioids, tricyclic antidepressants, and CSGB. Following each CSGB administration, the patient reported decreased hypersensitivity to sour-tasting foods, such as kimchi and oranges, with decreased pain and reduction of dysautonomic symptoms. This case demonstrates that overactivation of the sympathetic nervous system may influence sensitivity and regulation of gustatory receptors; therefore, a patient demonstrating CRPS symptoms, including taste alterations, may respond positively to CSGB therapy.

Determination of Adequate Entry Angle of Lumbar Sympathetic Ganglion Block in Korean

BACKGROUND: The target of lumbar sympathetic ganglion block is the anterolateral surface of the L2, 3 and 4 vertebral bodies, where the lumbar sympathetic ganglion usually lies. In most cases, a block-needle is inserted approximately 5-8 cm lateral to spinous process on the skin and directed to the anterolateral surface of vertebral body obliquely. The purpose of this study is to determine the safe entry angle and entry point in Korean by using the abdominal CT scan images. METHODS: The abdominal CT images of eighty five patients were recruited to this study. The minimal angle aimed at the lumbar sympathetic ganglion that can pass through the lateral aspect of body and maximal angle that avoids puncturing the kidney, ureter or retroperitoneal space were measured. The distance from midline to skin entry point was also measured. RESULTS: There was no significant difference in entry angle among L2, 3, and 4 level. The entry angle was similar in the right and left side, and in males and females. The entry angle of old age group was significantly smaller than that of young age group. The calculated safe entry angle was 30.5 +/- 0.4degrees and entry point was 7.7 +/- 0.2 cm and 6.7 +/- 0.1 cm lateral from midline in males and females respectively. CONCLUSION: These measurements can be used as a reference for lumbar sympathetic ganglion block and radiofrequency lesioning. Prior to performing the lumbar sympathetic ganglion block for cancer patients, the abdominal CT scan should be reviewed to prevent complications.

The Effects of Lumbar Sympathetic Ganglion Block in the Patients with Spinal Stenosis and the Skin Temperature Changes according to the Contrast Spread Patterns

BACKGROUND: We hypothesized that if a fluoroscopic image of the lumbar sympathetic ganglion block (LSGB) showed the spread patterns of contrast at both the L2/3 and L4/5 disc areas, then this would demonstrate a more profound blockade effect because the spread patterns are close to sympathetic ganglia. In addition, we compared the effects of LSGB and transforaminal epidural steroid injection (TFESI) for the patients suffering with spinal stenosis. METHODS: Eighty patients were divided into two groups (Group S: the patients treated with TFESI, Group L: the patients treated with LSGB). The patients of group L were classified into three groups (groups A, B and, C) according to their contrast spread pattern. The preblock and postblock temperature difference between the ipsilateral and contralateral great toe (DT(pre), DT(post), degrees C), and the DTnet were calculated as follows. DT(net) = DT(post) - DT(pre). RESULTS: Both group showed a significant reduction of the visual analogue score (VAS) and the Oswestry disability index (ODI) score. Only the patients of group L showed a significant increase of their walking distance (WD). Group A showed the most significant changes in the DT(post) (6.1 +/- 1.2degrees C, P = 0.021), and the DTnet (6.0 +/- 1.0degrees C, p = 0.023), as compared to group C. CONCLUSIONS: LSGB showed a similar effect on the VAS, and ODI, and a significant effect, on WD, compared with TFESI. Group A showed a significant sympatholytic effect, as compared to group C.

The Effects of Superior Cervical Sympathetic Ganglion Block on the Acute Phase Injury and Long Term Protection against Focal Cerebral Ischemia/Reperfusion Injury in Rats / 대한통증학회지

BACKGROUND: Cerebral blood vessels are innervated by sympathetic nerves from the superior cervical ganglia (SCG), and these nerves may influence the cerebral blood flow. The purpose of the present study was to evaluate the neuroprotective effect of superior cervical sympathetic ganglion block in rats that were subjected to focal cerebral ischemia/reperfusion injury. METHODS: Eighty male Sprague-Dawley rats (270-320 g) were randomly assigned to one of two groups (the ropivacaine group and a control group). In all the animals, brain injury was induced by middle cerebral artery (MCA) reperfusion that followed MCA occlusion for 2 hours. The animals of the ropivacaine group received 30microl of 0.75% ropivacaine, and their SCG. Neurologic score was assessed at 1, 3, 7 and 14 days after brain injury. Brain tissue samples were then collected. The infarct ratio was measured by 2.3.5-triphenyltetrazolium chloride staining. The terminal deoxynucleotidyl transferase mediated dUTP-biotin nick-end labeled (TUNEL) reactive cells and the cells showing caspase-3 activity were counted as markers of apoptosis at the caudoputamen and frontoparietal cortex. RESULTS: The death rate, the neurologic score and the infarction ratio were significantly less in the ropivacaine group 24 hr after ischemia/reperfusion injury. The number of TUNEL positive cells in the ropivacaine group was significantly lower than those values of the control group in the frontoparietal cortex at 3 days after injury, but the caspase-3 activity was higher in the ropivacaine group than that in the control group at 1 day after injury. CONCLUSIONS: The study data indicated that a superior cervical sympathetic ganglion block may reduce the neuronal injury caused by focal cerebral ischemia/reperfusion, but it may not prevent the delayed damage.

Superior Cervical Sympathetic Ganglion Block may not Influence Early Brain Damage Induced by Permanent Focal Cerebral Ischemia in Rats / 대한통증학회지

BACKGROUND: Cerebral blood vessels are innervated by sympathetic nerves from the superior cervical ganglion (SCG). The purpose of the present study was to evaluate the neuroprotective effect of superior cervical sympathetic ganglion block in rats subjected to permanent focal cerebral ischemia. METHODS: Thirty male Sprague-Dawley rats (270-320 g) were randomly assigned to one of three groups (control, lidocaine and ropivacaine). A brain injury was induced in all rats by middle cerebral artery occlusion with a nylon thread. The animals of the local anesthetic group received 30 microl of 2% lidocaine or 0.75% ropivacaine in the SCG. Neurologic scores were assessed 24 hours after brain injury. Brain samples were then collected. The infarct and edema ratios were measured by 2.3.5-triphenyltetrazolium chloride staining. RESULTS: There were no differences in the death rates, neurologic scores, or infarction and edema ratios between the three groups. CONCLUSIONS: These findings suggest that superior cervical sympathetic ganglion block may not influence the brain damage induced by permanent focal cerebral ischemia in rats.

Effect of Superior Cervical Sympathetic Ganglion Block on Brain Injury Induced by Focal Cerebral Ischemia/Reperfusion in a Rat Model / 대한통증학회지

BACKGROUND: Cerebral blood vessels are innervated by sympathetic nerves that originate in the superior cervical ganglia (SCG). This study was conducted to determine the effect of an SCG block on brain injury caused by focal cerebral ischemia/reperfusion in a rat model. METHODS: Male Sprague-Dawley rats (270-320 g) were randomly assigned to one of three groups (lidocaine, ropivacaine, and control). After brain injury induced by middle cerebral artery (MCA) occlusion/reperfusion, the animals were administered an SCG bloc that consisted of 30 microliter of 2% lidocaine or 0.75% ropivacaine, with the exception of animals in the control group, which received no treatment. Twenty four hours after brain injury was induced, neurologic scores were assessed and brain samples were collected. The infarct and edema ratios were measured, and DNA fragmented cells were counted in the frontoparietal cortex and the caudoputamen. RESULTS: No significant differences in neurologic scores or edema ratios were observed among the three groups. However, the infarct ratio was significantly lower in the ropivacaine group than in the control group (P<0.05), and the number of necrotic cells in the caudoputamen of the ropivacaine group was significantly lower than in the control group (P<0.01). Additionally, the number of necrotic and apoptotic cells in theropivacaine group were significantly lower than inthe control group in both the caudoputamen and the frontoparietal cortex (P<0.05). CONCLUSIONS: Brain injury induced by focal cerebral ischemia/reperfusion was reduced by an SCG block using local anesthetics. This finding suggests that a cervical sympathetic block could be considered as another treatment option for the treatment of cerebral vascular diseases.

Pulsed Radiofrequency Treatement of the Stellate Ganglion in Acute Herpes Zoster: A case report / 대한마취과학회지

Herpes zoster represents the reactivation of latent varicella-zoster virus located in the dorsal root ganglion. The virus multiplies and migrates to the skin surface producing a characteristic, usually painful, pustular eruption. Severe pain during the acute phase of herpes zoster has been associated with a higher risk of developing postherpetic neuralgia. Sympathetic ganglion block and somatic nerve block have been used for patients in the acute phase of herpes zoster to alleviate pain and prevent postherpetic neuralgia. Sympathetic nerve block appears to achieve these goals by blocking the profound sympathetic stimulation that is a result of the viral inflammation of the nerve and ganglion. However, they require repeated local anesthetic injections to relieve the symptoms of acute herpes zoster as well as to prevent the occurrence of postherpetic neuralgia. Pulsed radiofrequency has been proposed as safe, nondestructive treatment method. We present a case of acute herpes zoster that was managed with pulsed radiofrequency treatment. The results were satisfactory.

Lumbar Sympathetic Ganglion Block with Alcohol for Plantar Hyperhidrosis / 대한통증학회지

BACKGROUND: Chemical lumbar sympathetic ganglion block could potentially be used to treat plantar hyperhidrosis; therefore, we analyzed the outcome of lumbar sympathetic ganglion block using alcohol for the treatment of plantar hyperhidrosis. METHODS: Between March 1992 and June 2003, 356 patients with plantar hyperhidrosis underwent lumbar sympathetic ganglion block using alcohol. All 356 patients were followed up for 2 years and the results evaluated. There were 185 and 171 male and female patients, respectively, with a mean age of 25.1 years, ranging from 15.3 to 56.5 years old. Lumbar sympathetic ganglion block using alcohol was performed with fluoroscopic guidance under local anesthesia. RESULTS: The recurrence rate after 2 years was 34%. Compensatory hyperhidrosis, ejaculation failure, lower back pain and genitofemoral neuritis developed as complications in 132, 4, 12 and 2 patients, respectively. Of the 356 patients, 65% were satisfied. CONCLUSIONS: Lumbar sympathetic ganglion block using alcohol is an effective and safe method for the treatment of plantar hyperhidrosis, but more information about the complications and relatively high recurrence rates should be provided to the patient.

Dorsal Percutaneous Thoracic Sympathetic Ganglion Block with Alcohol for the Treatment of Palmar Hyperhidrosis / 대한통증학회지

BACKGROUND: Hyperhidrosis is the troublesome disorder of excessive perspiration, which affects as much as 0.15-1% of the population. There are many methods for treating hyperhidrosis. In this report, we present our experience of dorsal percutaneous thoracic sympathetic ganglion block (TSGB) using 99.9% ethyl alcohol for treating palmar hyperhidrosis. METHODS: Between March 1992 and July 2003, a total of 856 patients underwent TSGB for the treatment of palmar hyperhidrosis of which 625 were followed up for 2 years. There were 297 and 328 male and female patients, respectively, with a mean age of 23.9+/-7.7 years. TSGB was performed under fluoroscopic guidance using 99.9% ethyl alcohol at the T2 and T3 sympathetic ganglia. RESULTS: In the 625 patients, the recurrence rates within the 1st and 2nd years were 29 and 8%, respectively. Compensatory sweating occurred in 42.1% of patients, which was severe in 7.5%. Of the 625 patients 21.0 and 36.9% were either very satisfied or relatively satisfied with the outcome, respectively. CONCLUSIONS: Our report confirms that TSGB may be a good alternative to endoscopic thoracic sympathectomy in the treatment of palmar hyperhidrosis.

Thoracic Spinal Cord Stimulation and Radiofrequency Thermocoagulation of Lumbar Sympathetic Ganglion in a Patient with Complex Regional Pain Syndrome in the Lower Extremity: A case report / 대한통증학회지

Herein is described the successful treatment of complex regional pain syndrome type II with the combination treatment of spinal cord stimulation and radiofrequency thermocoagulation of the lumbar sympathetic ganglion. A 62 years old male patient, suffering from CRPS type II in his left lower extremity, visited our pain clinic. Medication and nerve blockade produced only slight improvement in his symptoms and signs. Therefore, a linear type spinal cord simulator was inserted into the thoracic epidural space, using a non-surgical percutaneous approach, with the cephalad lead located at the T11 level. Two months later, the repositioning of the electrode to the T12 level for more effective pain control, with radiofrequency thermocoagulation of lumbar sympathetic ganglion also performed at the left L2 and 3 levels for the control of trophic change. These resulted in significant pain relief and decreased trophic change, with no complications, after which the patient was able to resume a normal life.

A Review of Insertion Site for Lumbar Sympathetic Ganglion Block / 대한마취과학회지

BACKGROUND: Lumbar sympathetic ganglion block (LSGB) is one of the most frequently performed blocks in the field of interventional pain management. However, several complications can be expected if pain clinicians do not have a through understanding of radiological anatomy and current technique for locating block, landmarks are poor. Therefore, we devised a simple, safe, and patient tolerable block technique. METHODS: We selected patients scheduled for a LSGB with a body mass index of less than 25 kg/m2. After prone positioning, C-arm projection was adjusted obliquely until the tip of the L3 transverse process met the lateral margin of the corresponding vertebral body. Maintaining this angle, the skin entry point was determined at the lower one-third of the lateral margin of the vertebral body. We measured the distance from the mid-point of the spinous process to the skin entry point. A curved block needle was advanced using the tunnel vision technique, until the needle tip touched the lateral margin of the vertebral body. We also measured the position of the needle tip relative to the vertebral body in the lateral projection of the C-arm (lateral width percentage). Thereafter, the needle was slid along the lateral margin of the vertebral body to the anterior margin. RESULTS: The distance from the mid-point of the spinous process to the skin entry point was 6.5 +/- 1.0 cm. The angle of the C-arm projection was 22.0 +/- 3.8o. The depth from the skin entry point to the needle tip when touching the lateral margin of the vertebral body in the oblique projection of the C-arm was 8.5 +/- 0.9 cm. The lateral width percentage from the posterior margin of vertebral body was 49.0 +/- 7.0% and the entire depth of the curved needle from the skin entry point to the anterior margin of the vertebral body was 10.4 +/- 1.0 cm. CONCLUSIONS: This simple tunnel vision technique using a curved needle and an oblique C-arm projection is safe, simple and patient tolerable. In addition, it reduces block time and avoids repeated needle insertions. The tip of the L3 transverse process and the lateral margin of the corresponding vertebral body were found to be useful bony landmarks for the block. We believe that the provided depths and lateral width percentages may be useful for block in Koreans.

Effects of morphine tolerance and dependence on the fast excitatory synaptic transmission in sympathetic ganglia of rats / 中国药理学通报

Aim To study effects of morphine tolerance and dependence on the fast excitatory synaptic transmission in sympathetic ganglia of rats.Methods The isolated sympathetic ganglia,superior cervical ganglia(SCG), were made from control and morphine tolerant and dependent rats respectively.Effects of morphine tolerance and dependence on the fast excitatory synaptic transmission in rat sympathetic ganglia were studied by means of intracellular recording technique.Results ① Morphine(0.1～1.0 mmol?L~(-1))reversibly inhibited the amplitude of the fast excitatory postsynaptic potentials(f-EPSPs) in SCG neurons of control rats.② Compared with control group,inhibitory effects of morphine(0.5 mmol?L~(-1) and 1.0 mmol?L~(-1)) on f-EPSPs in SCG neurons of morphine tolerant and dependent rats were obviously decreased;③ Naloxone(0.1 mmol?L~(-1)),which had no significantly effect on f-EPSPs in SCG neurons of control rats,could reversibly facilitate the amplitude of f-EPSPs in SCG neurons of morphine tolerant and dependent rats;④ No significant difference of RMP and Rm was founded between SCG neurons of control and morphine tolerant and dependent rats.Conclusion The morphine tolerant and dependent of the fast excitatory synaptic transmission in rat sympathetic ganglia has been formed in morphine tolerant and dependent rats.

Infrared Thermographic Imaging in the Assessment of Successful Block on Lumbar Sympathetic Ganglion

This study examined the net changes in temperature at various regions of the lower extremities in an attempt to identify the regions demonstrating the most significant temperature changes following a lumbar sympathetic ganglion block (LSGB). Thermography was performed before and after the LSGB in 26 sympathetic nerve system disorder cases. The inspection points were the anterior and posterior surfaces of the thigh, the knee and leg, and the dorsal and plantar surfaces of the feet. The net increases in skin temperature following the LSGB (deltaT (net) ) at the plantar and dorsal surfaces of the feet, were 6.2 +/- 2.68 degrees C (mean +/- SD) and 3.9 +/- 1.89degrees C, respectively, which were higher than those observed in the other regions of the lower extremities (p < 0.05). The areas, in order of decreasing deltaT (net), are as follows: the plantar surface of the foot, the dorsal surface of the foot, the shin, the anterior surface of the knee, the calf, the posterior surface of the knee, the anterior surface of the thigh, and the posterior surface of the thigh. There was one case of orthostatic hypotension during the thermography procedure. In conclusion, thermographic imaging is a useful method for demonstrating the success of a LSGB in various diseases. An evaluation of the deltaT (net) on the plantar surface of the feet using thermographic imaging is the most effective, simple, and safe method for assessing a successful LSGB.

Combined inhibitory effects of propofol and midazolam on macroscopic sodium currents in rat sympathetic ganglion neurons / 中国临床药理学与治疗学

AIM: To study the interactions of propofol and midazolam on the whole cell sodium channel currents in rat sympathetic ganglion neurons. METHODS: Whole cell patch clamp recordings were made from enzymatically isolated rat (7- 10 d ) superior cervical sympathetic ganglion neurons. Isobolographic analysis was applied to evaluate the potency of combinations of propofol and midazolam on Na + channel currents. RESULTS: Under V h= 80 mV and V t= 0 mV . Propofol and midazolam dose dependently blocked Na + currents with a mean drug concentration required to produce 50% current inhibition (IC 50 ): 33.12 ?mol?L -1 and 18.35 ?mol?L -1 ; clinically relevant concentrations of propofol and midazolam reduced Na + peak currents by 27.66 % (P

Inhibitory mechanisms of diazepam on macroscopic sodium currents in rat sympathetic ganglion neurons / 中国临床药理学与治疗学

Aim The effects of diazepam on the whole cell sodium currents in rat sympathetic ganglion neurons were studied to investigate the mechanisms by diazepam mediates hypotension. Methods Whole cell patch clamp recordings were performed on enzymatically isolated rat superior cervical sympathetic ganglion neurons. Results Diazepam dose dependently blocked the whole cell sodium currents. Under a V t of 0 mV and a V h of 80 mV 0.3 ?mol?L -1 diazepam reduced sodium peak currents by 14.76 %(P