Left atrial ganglionated plexi detection is related to heart rate and early recurrence of atrial fibrillation after surgical ablation

Abstract INTRODUCTION: Left atrial ganglionated plexi ablation is an adjuvant technique used to increase the success rate of surgical ablation of atrial fibrillation. Ganglionated plexi ablation requires previous detection. We aimed to assess determinants of successful ganglionated plexi detection and to correlate range of ganglionated plexi ablation with risk of early atrial fibrillation recurrence. METHODS: The study involved 34 consecutive patients referred for surgical coronary revascularization with concomitant atrial fibrillation ablation. Ganglionated plexi detection was done by inducing vagal reflexes in the area of the pulmonary veins and left atrial fat pads. RESULTS: Detection of GP was successful in 85% of the patients. There was no difference in preoperative characteristics nor in atrial fibrillation type between patients in whom ganglionated plexi detection was successful and others. The number of detected ganglionated plexi correlated significantly only with preoperative resting heart rate. Significant negative correlation was found in patients with preoperative heart rate>75 beat/min in terms of total number of detected ganglionated plexi (P=0.04). Average number of detected ganglionated plexi was significantly higher in patients with in-hospital atrial fibrillation recurrence requiring electrical cardioversion (3.8±3) in comparison to rest of the study population (2±1.3; P=0.02). In patients in whom 4 or more ganglionated plexi were detected, significantly increased risk of in-hospital atrial fibrillation recurrence was observed (OR 15; 95% CI 1.5-164; P=0.003). CONCLUSION: Left atrial ganglionated plexi detection was unsuccessful in a considerable percentage of patients. Preoperative heart rate significantly influenced positive ganglionated plexi detection and number of ablated ganglia. Higher number of detected ganglionated plexi was related with early recurrence of atrial fibrillation.

Gintonin facilitates catecholamine secretion from the perfused adrenal medulla

The present study was designed to investigate the characteristics of gintonin, one of components isolated from Korean Ginseng on secretion of catecholamines (CA) from the isolated perfused model of rat adrenal gland and to clarify its mechanism of action. Gintonin (1 to 30 µg/ml), perfused into an adrenal vein, markedly increased the CA secretion from the perfused rat adrenal medulla in a dose-dependent fashion. The gintonin-evoked CA secretion was greatly inhibited in the presence of chlorisondamine (1 µM, an autonomic ganglionic bloker), pirenzepine (2 µM, a muscarinic M₁ receptor antagonist), Ki14625 (10 µM, an LPA₁/₃ receptor antagonist), amiloride (1 mM, an inhibitor of Na⁺/Ca²⁺ exchanger), a nicardipine (1 µM, a voltage-dependent Ca²⁺ channel blocker), TMB-8 (1 µM, an intracellular Ca²⁺ antagonist), and perfusion of Ca²⁺-free Krebs solution with 5mM EGTA (a Ca²⁺chelater), while was not affected by sodium nitroprusside (100 µM, a nitrosovasodialtor). Interestingly, LPA (0.3~3 µM, an LPA receptor agonist) also dose-dependently enhanced the CA secretion from the adrenal medulla, but this facilitatory effect of LPA was greatly inhibited in the presence of Ki 14625 (10 µM). Moreover, acetylcholine (AC)-evoked CA secretion was greatly potentiated during the perfusion of gintonin (3 µg/ml). Taken together, these results demonstrate the first evidence that gintonin increases the CA secretion from the perfused rat adrenal medulla in a dose-dependent fashion. This facilitatory effect of gintonin seems to be associated with activation of LPA- and cholinergic-receptors, which are relevant to the cytoplasmic Ca²⁺ increase by stimulation of the Ca²⁺ influx as well as by the inhibition of Ca²⁺ uptake into the cytoplasmic Ca²⁺ stores, without the increased nitric oxide (NO). Based on these results, it is thought that gintonin, one of ginseng components, can elevate the CA secretion from adrenal medulla by regulating the Ca²⁺ mobilization for exocytosis, suggesting facilitation of cardiovascular system. Also, these findings show that gintonin might be at least one of ginseng-induced hypertensive components.

Two Cases of Neurotoxin Tetramine Poisoning Following Ingestion of Buccinum Striatissinum

Some carnivorous gastropods have heat stable tetramine toxins in their salivary glands. This toxin is an autonomic ganglionic blocking agent that enables them to catch the prey easily by paralyzing their targets. Acute tetramine toxin poisoning in humans from eating whelks has been well described based on numerous cases, but is rare in Korea. Symptoms of tetramine poisoning include eyeball pain, blurred vision, headache, dizziness, muscular twitching, tingling of hands and feet, weakness, paralysis and sometimes collapse. Gastrointestinal symptoms, such as abdominal pain, nausea, and vomiting can also occur. However, intoxication is self-limiting and patients will usually recover in about 24 hours. Herein, we report 2 cases of tetramine poisoning after ingestion of Buccinum striatissinum as meat and soup.

Two Cases of Neurotoxin Tetramine Poisoning Following Ingestion of Buccinum Striatissinum

Some carnivorous gastropods have heat stable tetramine toxins in their salivary glands. This toxin is an autonomic ganglionic blocking agent that enables them to catch the prey easily by paralyzing their targets. Acute tetramine toxin poisoning in humans from eating whelks has been well described based on numerous cases, but is rare in Korea. Symptoms of tetramine poisoning include eyeball pain, blurred vision, headache, dizziness, muscular twitching, tingling of hands and feet, weakness, paralysis and sometimes collapse. Gastrointestinal symptoms, such as abdominal pain, nausea, and vomiting can also occur. However, intoxication is self-limiting and patients will usually recover in about 24 hours. Herein, we report 2 cases of tetramine poisoning after ingestion of Buccinum striatissinum as meat and soup.

Blood vessels i ganglia in human esophagus migt explain the higher frequency of megaesophagus compared with megacooon / Vasos sanguíneos em gânglios no esôfago humano poderiam explicar a maior freqüência de megaesôfago comparado com megacolon

This study aimed to determine the existence of blood vessels within ganglia of the myenteric plexus of the human esophagus and colon. At necropsy, 15 stillborns, newborns and children up to two years of age, with no gastrointestinal disorders, were examined. Rings of the esophagus and colon were analyzed and then fixed in formalin and processed for paraffin. Histological sections were stained by hematoxylin-eosin, Giemsa and immunohistochemistry for the characterization of endothelial cells, using antibodies for anti-factor VIII and CD31. Blood vessels were identified within the ganglia of the myenteric plexus of the esophagus, and no blood vessels were found in any ganglia of the colon. It was concluded that the ganglia of the myenteric plexus of the esophagus are vascularized, while the ganglia of the colon are avascular. Vascularization within the esophageal ganglia could facilitate the entrance of infectious agents, as well as the development of inflammatory responses (ganglionitis) and denervation, as found in Chagas disease and idiopathic achalasia. This could explain the higher frequency of megaesophagus compared with megacolon.

Este estudo teve como objetivo avaliar se existem ou não vasos sanguíneos no interior de gânglios do plexo mientérico do esôfago e cólon humano. Foram examinados 15 casos de necrópsias de natimortos, recém-nascidos e crianças de até dois anos de idade, sem alterações gastrintestinais, que faleceram por doenças em outros órgãos. Foram analisados anéis do esôfago e cólon, fixados em formol e processados para inclusão em parafina. Cortes histológicos escalonados foram corados pelas técnicas de hematoxilina-eosina, Giemsa e imuno-histoquímica para caracterização das células endoteliais, utilizando-se os anticorpos anti-fator VIII e CD 31. Foram identificados vasos sanguíneos no interior de gânglios do plexo mientérico do esôfago em todos os casos e não foram vistos vasos sanguíneos em nenhum gânglio do cólon. Concluímos que os gânglios do plexo mientérico do esôfago são vascularizados e, os do cólon, avasculares. A vascularização no interior dos gânglios do esôfago pode facilitar a entrada de agentes infecciosos, bem como o desenvolvimento de respostas inflamatórias (ganglionite) e denervação, como encontrados na doença de Chagas e na acalásia idiopática. Isso pode explicar a frequência maior de megaesôfago comparado com megacólon.

Key-Gaskell syndrome in Brazil: first case report / Síndrome de Key-Gaskell: primeiro relato de caso no Brasil

Feline dysautonomia is a devastating disease characterized by neuronal degeneration in autonomic ganglia that results in clinical signs related to dysfunction of the sympathetic and parasympathetic nervous systems. The cause is unknown and this disease has a poor prognosis and no definitive treatment. Most reports have been described in few countries around the world, but the prevalence may be underestimated in countries like Brazil. This study describes the progression and clinicopathological changes of dysautonomia in a 17-month-old female Brazilian shorthair cat...

Disautonomia felina é uma doença devastadora, caracterizada por degeneração neuronal em gânglios autonômicos, a qual resulta em sinais clínicos relacionados à disfunção dos sistemas simpático e parassimpático. Sua causa é desconhecida, o prognóstico desfavorável e não há tratamento definitivo disponível. A maioria dos relatos foi descrita em países ao redor do mundo, mas sua prevalência pode estar subestimada em países como o Brasil. Este estudo descreve a progressão e as alterações clínico-patológicas da disautonomia em um gato de pelo curto brasileiro, do sexo feminino, de 17 meses de idade...

Incidentally detected ganglioneuroma during pregnancy: A case report

Retroperitoneal ganglioneuroma is a rare benign tumor, which is included in the neuroblastomas group. It can occur anywhere along the peripheral autonomic ganglion sites, and the tumor is often incidentally detected in asymptomatic patients or may produce symptoms related to the slow growing tumor. Surgical excision is the treatment of choice and the prognosis is good. We report a case of retroperitoneal ganglioneuroma, which was incidentally detected in the first trimester of pregnancy in a 29-year-old woman. Surgical resection of the ganglioneuroma was done at the time of cesarean section at full term without complications.

Objective evaluation of plantar hyperhidrosis after sympathectomy

OBJECTIVE: The aim of the present study was to prospectively, randomly, blindly, and objectively investigate how surgery affects plantar sudoresis in patients with palmar and plantar hyperhidrosis over a one-year period using a sudorometer (VapoMeter). METHODS: From February 2007 to May 2009, 40 consecutive patients with combined palmar hyperhidrosis and plantar hyperhidrosis underwent video-assisted thoracic sympathectomy at the T3 or T4 ganglion level (15 women and 25 men, with a mean age of 25 years). RESULTS: Immediately after the operation and during the one-year follow-up, all of the patients were free from palmar hyperhidrosis episodes. Compensatory hyperhidrosis of varying degrees was observed in 35 (87.5%) patients after one year. Only two (2.5%) patients suffered from severe compensatory hyperhidrosis. There was a large initial improvement in plantar hyperhidrosis in 46.25% of the cases, followed by a progressive regression of that improvement, such that only 30% continued to show this improvement after one year. The proportion of patients whose condition worsened increased progressively (from 21.25% to 47.50%), and the proportion of stable patients decreased (32.5% to 22.50%). This was not related to resection level; however, a lower intensity of plantar hyperhidrosis prior to sympathectomy correlated with worse evolution. CONCLUSION: Patients with palmar hyperhidrosis and plantar hyperhidrosis who underwent video-assisted thoracic sympathectomy to treat their palmar hyperhidrosis exhibited good initial improvement in plantar hyperhidrosis, which then decreased to lesser degrees of improvement over a one-year period following the surgery. For this reason, video-assisted thoracic sympathectomy should not be performed when only plantar hyperhidrosis is present.

Morphoquantitative study of the submucous plexus (of Meissner) of the jejunum-ileum of young and old guinea pigs / Estudo morfoquantitativo do plexo submucoso (de Meissner) do jejuno-íleo de cobaias jovens e velhas

OBJECTIVE: To study the aging of submucous plexus of the small intestine (jejunum-ileum) of the guinea pigs from the quantitative, structural and ultrastructural perspective. METHOD: Chemical preparations of membrane of the jejunum-ileum of old and young animals with the use of light and electronic microscope. RESULTS: The ganglia of young animals presented between 1 and 56 neurons and the old animals presented from 1 to 30 neurons. The mean density of the ganglia by cm² in the young jejunum-ileum was of 551±36.89 and in the old one 413±11.86. The density of the neurons was 5011±291.11 neurons/cm² average in young animals and 2918±120.70 neurons/cm² in the old ones. The size of the neurons varied in both age groups. The collagen fibers in the ganglia of old animals they were condensed. Degenerated mitochondrias in the interior of the cell were frequent in the old animals. CONCLUSION: In submucous plexus of the jejunum-ileum there is a loss of 38 percent of the neurons with aging.

OBJETIVO: Estudar o envelhecimento do plexo submucoso do intestino delgado (jejuno-íleo) das cobaias do ponto de vista quantitativo, estrutural e ultra-estrutural. MÉTODO: Preparados de membrana do jejuno-íleo de animais jovens e velhos com a utilização de microscopia de luz e eletrônica. RESULTADOS: Os gânglios de animais jovens apresentaram entre 1 e 56 neurônios e os animais velhos apresentaram de 1 a 30 neurônios. A densidade média dos gânglios por cm² no jejuno-íleo jovem foi de 551±36,89 e no velho foi de 413±11,86. A densidade dos neurônios foi de 5011±291,11 neurônios/cm² em média nos animais jovens e 2918±120,70 neurônios/cm² nos velhos. O tamanho dos neurônios variou em ambos os grupos etários. As fibras colágenas nos gânglios de animais velhos estavam mais condensadas. Mitocôndrias degeneradas no interior da célula foram freqüentes nos animais velhos. CONCLUSÃO: No plexo submucoso do jejuno-íleo há uma perda de 38 por cento dos neurônios com o envelhecimento.

Efectos del losartán sobre el glomus carotídeo en ratas normotensas adultas / Effects of losartan on the carotid glomus in adult normotensive rats

Recientemente comunicamos lesiones graves en el glomus carotídeo y los ganglios autonómicos de ratas SHR y sugerimos que este efecto se debía más al aumento de la presión arterial que al envejecimiento. Posteriormente demostramos, en SHR, que el ramipril, en comparación con el atenolol, ejerce un efecto protector sobre estas estructuras más allá de la reducción de la presión arterial. Teniendo en cuenta que no existen trabajos que describan los cambios que origina el bloqueo AT1 sobre la morfología del glomus en ratas normotensas, se realizó el presente estudio con el objetivo de evaluar el efecto del losartán sobre esta estructura de ratas Wistar macho tratadas durante 8 meses. Se emplearon 14 ratas de 4 semanas de edad, divididas en grupos control y losartán (10 mg/kg/día en el agua de bebida). La presión sistólica (PAS) se registró al inicio y luego mensualmente. A la edad de 9 meses se sacrificaron las ratas y se extrajeron los glomus carotídeos, se tiñeron con hematoxilina-eosina y tricrómico de Masson y se procesaron para histomorfometría con un analizador de imágenes. El grupo control registró una PAS de 115 ± 8,1, mientras que en el grupo losartán fue de105 ± 8,3 mm Hg (p = 0,0375). Histomorfométricamente, el grupo tratado mostró un área mayor del glomus con respecto al control (497.931 ± 48.783 versus 59.668 ± 6.196 µm2; p <0,0001) y una relación pared/luz en las arteriolas glómicas de 0,7 ± 0,1 versus 2,7 ± 0,6,respectivamente (p < 0,0001). El grupo control mostró disminución del área glómica y un aumento de la relación pared/luz, lo cual sugiere que la atrofia de las estructuras estudiadas a través del aumento de la edad se vincula con el aporte nutricio arterial.

Dissection of cavernous nerves in rat and model of neurological erectile dysfunction / 法医学杂志

OBJECTIVES@#To identify rat cavernous nerve and establish a rat model of erectile dysfunction caused by injury of cavernous nerve.@*METHODS@#Ten rats were undergone dissections. 30 experimental rats were randomized into 2 groups, cavernous nerve were identified by electrical stimulation. One month after surgery, rat models were evaluated by electrical stimulation.@*RESULTS@#The anatomic structure of cavernous nerve in rats are highly similar to human beings, the erection can be evoked by stimulating cavernous nerves, and after cavernous nerve injury it can not be evoked (P < 0.05).@*CONCLUSION@#Because of the highly similarity of cavernous nerve between rats and human beings, so as the suitable price, rat should be used as the ideal ED experimental animal. The model of ED caused by cavernous nerve injury is reliable.

The Effect of Alcohol in the Nicotinic Acetylcholine Receptor / 대한정신약물학회지

OBJECTIVE: It has been well known that alcohol can modulate several ligand-gated ion channel and voltage-gated ion channels. But the roles of alcohol in the autonomic neurons still remain unclear. In this study, thus we characterized the neuronal acetylcholine receptor (nnAChRs) and investigated the modulation of nnAChRs by ethanol (EtOH). METHODS: We used whole-cells which were acutely dissociated male rat major pelvic ganglion (MPG) neurons, and used gramicidin perforated patch clamp techniques. RESULTS: MPG neurons can be classified on the basis of the response of the soma membrane to depolarizing current pulses ; either tonic or phasic neurons. Sympathetic neurons expressing T-type Ca(2+) channels showed tonic firing pattern, while parasympathetic neurons lacking T-type Ca(2+) channels phasic firing to depolarizing current pulses. When hyperpolarizing currents were injected, sympathetic neurons produced post-anodal rebound spikes, while parasympathetic neurons were silent. Under current clamp mode, Acetylcholine (ACh) evoked significant membrane depolarization and produced subsequently marked membrane hyperporization. Under whole-cell mode, application of ACh-induced inward currents held at holding potentials below 0 mV and reversal potential was close to 0 mV, an equilibrium potential of nonselective cation channel. The ACh-activated current was blocked by methyllycaconitine (MLA ; 10 micrometer), hexamethonium (100 micrometer) and alpha-bungarotoxin (alpha-BuTx ; 100 nM), nAChRs antagonists. EtOH (40 mM) potentiated ACh-induced depolarization and hyperpolarization. EtOH also increased both alpha-BuTx-sensitive and -insensitive ACh-activated currents. Futhermore, EtOH potentiated 5-HT-activated current but had a little effect on GABA-activated current. CONCLUSION: These results suggest that EtOH modulates nnAChRs and 5-HT receptors in MPG neurons.

Intraganglionic laminar endings act as mechanoreceptors of vagal afferent nerve in guinea pig esophagus / 生理学报

Intraganglionic laminar endings (IGLEs) have been supposed to be the mechanoreceptors in the gut by electrophysiological recording techniques. But the specialized morphology of IGLEs could not be displayed closely associated with this function and the mechanism that IGLEs act as the mechanotransduction sites in the gut is not yet well understood. In the present study, we used styryl dye FM1-43 combined with stretch stimulation in the guinea pig esophagus to test whether IGLEs acted as the mechano-sensitive receptors of the vagal afferent nerves. At the same time, the special structure of IGLEs displayed by FM1-43 was further confirmed by neurobiotin anterograde labeling technique. To further investigate the characteristics of IGLEs as mechanosensitive receptors, different drugs were used to block or stimulate IGLEs activation. Our results indicated that only in the stretched preparation could FM1-43 enter the IGLEs and completely display their specialized structure, which was consistent with that shown by neurobiotin. The amount of IGLEs shown by stretch-evoked FM1-43 staining was much more than that shown without stretch stimulation [(90.4 +/- 9.5) % vs (10.7 +/- 2.1) %, P<0.05]. Ca(2+), TTX (0.6 mumol/L), atropine (0.6 mumol/L), SKF (50 mumol/L), and gadolium (100 mumol/L) had no effect on the IGLEs activation. But for benzamil (100 mumol/L), an epithelial sodium channel blocker, activation of IGLEs by stretch stimulation was significantly blocked. The potent ATP analogue, alpha,beta-methylene ATP (100 mumol/L) could not activate FM1-43 staining without stretch. These results indicate that IGLEs are sensitive to mechanical stimulation. This could lead to the deduction that IGLEs act as the mechanoreceptors of vagal afferent nerve. IGLEs could transmit mechanical stimuli directly through ion channels, independent of neurotransmitter release and action potential propagation. The stretch-sensitive channels on IGLEs probably belong to the epithelial sodium channel family rather than voltage-gated sodium ion channels. Furthermore, styryl dye FM1-43 is a useful activity-dependent marker to demonstrate the structure and function of IGLEs in guinea pig esophagus.

Modulatory Role of Adenylyl Cyclase and Protein Kinase A (PKA) in 5-hydroxytriptamine3 Induced Intracellular Calcium Increase in Parasympathetic Neurons of Rat Major Pelvic Ganglia / 대한비뇨기과학회지

PURPOSE: Serotonin has effects on the bladder contraction or urethral sphincter tone. Different subtypes of 5-hydroxytriptamine (5-HT) receptors appear to mediate the effects of serotonin on voiding. 5-HT1 and 5-HT2, metamorphic receptors, are examined well. However 5-HT3, ionotrophic receptors, are not examined well. Pelvic ganglia provide the majority of the innervation of the lower urinary tract. Major pelvic ganglia (MPG) in rats are autonomic ganglia, containing both sympathetic and parasympathetic neurons related with voiding. We examined the modulatory role of adenylyl cyclase (AC) and protein kinase A (PKA) in 5-HT3 induced intra cellular calcium increase in rat MPG. MATERIALS AND METHODS: The regulatory effects by AC and PKA were investigated in a single neuron of male rat major pelvic ganglia using patch clamp and fluorescence Ca2+ measurement techniques. RESULTS: Inward currents were induced by 5-HT (10microM) at only parasympathetic neurons of MPG. MDL7222 (10(-6)M), selective 5-HT3 receptor antagonists, completely abolished the 5-HT induced inward currents. 5-HT (10microM) induced intracelluar increases of calcium. These increases were blocked by an AC inhibitor SQ22536 (2x10(-5M)) and myristoylated PKA inhibitor (10(-7)M). Furthermore, foskolin (10(-6)M), AC activator, augmented the 5-HT induced intracellular calcium increase. CONCLUSIONS: The activation of AC/PKA-dependent pathway could enhance 5-HT3 induced intacellular calcium increase in parasympathetic neurons of rat MPG and these is helpful for the better understanding the mechanisms of the bladder contraction or urethral sphincter tone.

A Case of Cutaneous Neurofibroma Intimately Contacted with Intrathoracic and Chest Wall Plexiform Neurofibroma in Von Recklinghausen's Disease

Congenital neurofibromatosis type 1, or Von Recklinghausen's disease is an autosomal dominant disorder characterized by neurofibroma, pigmented skin lesions (Cafe-au-lait macules), iris hamartomas and meningeal tumors, but rarely, by autonomic ganglia tumors, such as pheochromocytomas. We have experienced an intrathoracic and chest wall plexiform neurofibroma intimately contacted with collagenoma-like, dome-shaped skin lesions of type 1 neurofibromatosis, which are relatively rare and interesting, but can be regarded as typical findings in neurofibromatosis. Although intrathoracic neurogenic tumors are not uncommon, cases like ours are interesting, as the feature of collagenoma-like skin neurofibroma was very closely apposited with chest wall neurofibroma. Our case had no aypical features of malignancy and the patient was clinically followed up without recurrence.

Effect of Fluoxetine on Calcium or Potassium Channels in the Neuron of Rat Major Pelvic Ganglia / 대한비뇨기과학회지

PURPOSE: The major pelvic ganglia (MPG) provide the majority of the innervations to the lower urinary tract. The pelvic ganglia are unique autonomic ganglia that contain both sympathetic and parasympathetic neurons. It has been known that the low-threshold voltage-gated (T-type) Ca2 channels are only expressed only in the sympathetic neurons, whereas these channels are absent in parasympathetic neurons. In the present study, we examined the effect of fluoxetine, a world-wide used antidepressant, on the voltage-dependent Ca2 and K currents in the adrenergic neurons of the MPG. MATERIALS AND METHODS: The effect of fluoxetine on the voltage-dependent Ca2 and K currents in the adrenergic neurons of the MPG were examined using the whole-cell patch-clamp technique. RESULTS: Fluoxetine inhibited the voltage-activated Ca2 currents in the adrenergic neurons of the MPG. Both high-threshold (HVA) and low- threshold (LVA, T-type) Ca2 currents were inhibited by fluoxetine with an IC50 of 5.3 and 10.8microM, respectively. Fluoxetine also decreased the both the peak amplitude and the plateau of the outward K currents. The inhibition of the peak K currents by fluoxetine was concentration- dependent with an IC50 of 3.2microM. The inhibitions of the Ca2 and K currents were quickly reversible upon washout of the fluoxetine. CONCLUSIONS: These results provide evidence for the direct inhibition of the voltage dependant Ca2 and K currents by fluoxetine and these inhibitory effects could modify the synaptic transmission in adrenergic neurons of the MPG.

Characterization of Acetylcholine-induced Currents in Male Rat Pelvic Ganglion Neurons

The pelvic ganglia provide autonomic innervations to the various urogenital organs, such as the urinary bladder, prostate, and penis. It is well established that both sympathetic and parasympathetic synaptic transmissions in autonomic ganglia are mediated mainly by acetylcholine (ACh). Until now, however, the properties of ACh-induced currents and its receptors in pelvic ganglia have not clearly been elucidated. In the present study, biophysical characteristics and molecular nature of nicotinic acetylcholine receptors (nAChRs) were studied in sympathetic and parasympathetic major pelvic ganglion (MPG) neurons. MPG neurons isolated from male rat were enzymatically dissociated, and ionic currents were recorded by using the whole cell variant patch clamp technique. Total RNA from MPG neuron was prepared, and RT-PCR analysis was performed with specific primers for subunits of nAChRs. ACh dose-dependently elicited fast inward currents in both sympathetic and parasympathetic MPG neurons (EC50; 41.4microliterM and 64.0microliterM, respectively). ACh-induced currents showed a strong inward rectification with a reversal potential near 0 mV in current-voltage relationship. Pharmacologically, mecamylamine as a selective antagonist for alpha3beta4 nAChR potently inhibited the ACh-induced currents in sympathetic and parasympathetic neurons (IC50; 0.53micrometer and 0.22micrometer, respectively). Conversely, alpha- bungarotoxin, alpha-methyllycaconitine, and dihydro-beta-erythroidine, which are known as potent and sensitive blockers for alpha7 or alpha4beta2 nAChRs, below micromolar concentrations showed negligible effect. RT-PCR analysis revealed that alpha3 and beta4 subunits were predominantly expressed in MPG neurons. We suggest that MPG neurons have nAChRs containing alpha3 and beta4 subunits, and that their activation induces fast inward currents, possibly mediating the excitatory synaptic transmission in pelvic autonomic ganglia.

Effects on erectile function of transplanted major pelvic ganglion into the corpus cavernosum of adult rats with bilateral cavernous nerve injury / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the effects on erectile function of transplanted major pelvic ganglion into the corpus cavernosum of adult male rats undergoing transection of bilateral cavernous nerves.</p><p><b>METHODS</b>Twenty-six male Sprague-Dawley rats (3 - 4 month-old and 300 - 400 g/each) were divided into 2 groups: experimental group (transection of bilateral cavernous nerves and transplantation of left ganglion into left crus of penis, n = 16) and control group (transection of bilateral cavernous nerves only, n = 10). Erectile function was measured by injecting APO, and intracavernous pressure was measured 1 and 3 months afterwards by electric-stimulating the right major pelvic ganglion or the left crus. Half animals in each group were sacrificed 1 and 3 months afterwards for detecting nNOS-containing nerve fibers of corpus cavernosum. Electron microscopy of the implanted area was performed to assess neuronal survival.</p><p><b>RESULTS</b>Both of the two groups have no erectile response to APO injection. Electrostimulation on the right major pelvic ganglion and left crus failed to produce erection in experimental group. The mean pressure changes in the two groups, measured by stimulating the left crus, were (9.41 +/- 3.20) and (4.16 +/- 2.58) cmH(2)O 1 month afterwards, and (13.67 +/- 4.18) and (5.09 +/- 2.74) cmH(2)O 3 months afterwards, respectively (P < 0.05). An increased number of nNOS-containing nerve fibers in left crus was detected in experimental group 1 and 3 months later, compared with control one (218.7 +/- 24.5, 18.0 +/- 3.7; 183.2 +/- 19.7, 19.0 +/- 3.8; P < 0.05). Ultrastructure examination by transmission electron microscope confirmed the survival of the implanted ganglion.</p><p><b>CONCLUSION</b>Major pelvic ganglion can survive in the corpus cavernosum, and it has significant effects on the number of nNOS-containing nerve fibers and the alteration of intracavernous pressure.</p>

The Actions of Adenosine on Voltage-dependent K+ Currents in Neurons of Male Rat Major Pelvic Ganglia / 대한비뇨기과학회지

PURPOSE: The major pelvic ganglia (MPG) function as a relay center for autonomic pathways to the urogenital organs, such as the urinary bladder, vas deference, and penis. It is well known that adenosine acts as an important neuromodulator in various neuronal tissues. Several studies have suggested that some of these actions are coupled with potassium conductances. However, the exact mechanisms are unclear. Therefore, the roles of adenosine on the various potassium channels, in MPG neurons, were investigated. MATERIALS AND METHODS: Single neurons of the MPGs, located on the lateral surfaces of the prostate gland, from male rats were enzymatically dissociated. Ionic currents were recorded using the whole-cell variant patch-clamp technique. RESULTS: Two types of voltage-dependent outward potassium channels were isolated in the MPG neurons using whole-cell voltage protocols. One was the transient outward potassium current (type A-current, IA), the other was the delayed rectifier potassium current (IKDR). The IA and IKDR were recorded in both adrenergic and nonadrenergic neurons, which were distinguished by the existence of T-type calcium currents. Both the adrenergic and nonadrenergic neurons had the same kind of outward potassium currents. Application of adenosine (10(-4)M) increased the IA reversibly. N-cyclopentyladenosine (CPA, 10(-5)M), an A1 selective agonist, produced the same effect. However, the delayed rectifier components were not affected by the adenosine or CPA. The effects of adenosine and CPA on the IA were mostly prevented by pretreatment with DPCPX, an A1 selective antagonist. CONCLUSIONS: Adenosine increased the IA only, via the selective activation of A1 adenosine receptors. The augmentation of A-currents by adenosine may reduce neuronal firings, and then contribute to regulation of neuronal excitability in male rat MPG neurons.