Serotonin Discharge Regulation by Additional Neurotransmitters of Rat Hippocampus Associated With the Continence Central Circuit / 대한배뇨장애요실금학회지

Purpose@#The lower urinary tract is believed to be centrally regulated with the involvement of a range of neurotransmitters. The parasympathetic excitatory input to the urinary bladder is suppressed when the serotonergic system is activated, and thereby voiding is blocked. In healthy people, continence is usually underpinned by hippocampal formation (circuit 3). In order to advance knowledge of how serotoninergic neurons and additional nerve fibers were correlated, the purpose of the present work was to research how the discharge of serotonin from hippocampal slices was affected by different neurotransmitters in rat models. @*Methods@#The adopted procedure involved administration of the central neurotransmitters acetylcholine, norepinephrine, dopamine, N-methyl-D-aspartate (NMDA), gamma-aminobutyric acid (GABA), glycine, and neuropeptide Y as well as monitoring of the alterations in the discharge of [3H]5-hydroxytryptamine (5-HT). Furthermore, to determine whether the effect of the neurotransmitters was influenced by interneuron, tetrodotoxin was also employed. @*Results@#Acetylcholine (10-5M) did not alter [3H]5-HT discharge, whereas more 5-HT was discharged from the hippocampal slices of rats under stimulation by norepinephrine (10-5M) as well as dopamine (10-5M) and tetrodotoxin (10-6M) did not inhibit the discharge. By contrast, tetrodotoxin inhibited the discharge of [3H]5-HT that was exacerbated by NMDA (10-4M). Meanwhile, compared to control, GABA (10-5M), glycine (10-5M), or neuropeptide Y (10-6M) did not alter the [³H]5-HT discharge. @*Conclusions@#From the research findings, it can be concluded that 5-HT discharge from rat hippocampus is enhanced by norepinephrine and dopamine through direct effect on the 5-HT neuronal terminal. By contrast, 5-HT discharge is intensified by NMDA by activating interneurons.

Liberation of Serotonin Is Not Unaffected by Acetylcholine in Rat Hippocampus / 대한배뇨장애요실금학회지

Purpose@#Raised cerebral titers of acetylcholine have notable links with storage symptomatology related to lower urinary tract symptoms. The hippocampus contributes to the normal control of continence in the majority of instances (circuit 3). Owing to synaptic connections with other nerve cells, acetylcholine affects the micturition pathway via the liberation of additional cerebral neurotransmitters. Despite the fact that cerebral serotonin is a key inhibitor of reflex bladder muscle contractions, the influence of acetylcholine on its liberation is poorly delineated. The current research was conducted in order to explore the role of acetylcholine in serotonin liberation from sections of rat hippocampus in order to improve the comprehension of the relationship between cholinergic and serotonergic neurons. @*Methods@#Hippocampal sections from 6 mature male Sprague-Dawley rats were equilibrated over a 30-minute period in standard incubation medium so as to facilitate [3H]5-hydroxytryptamine (5-HT) uptake. The cerebral neurotransmitter, acetylcholine, was applied to the sections. Aliquots of drained medium solution were utilized in order to quantify the radioactivity associated with [3H]5-HT liberation; any alterations in this parameter were noted. @*Results@#When judged against the controls, [3H]5-HT liberation from the hippocampal sections remained unaltered following the administration of acetylcholine, implying that this agent has no inhibitory action on this process. @*Conclusions@#Serotonin liberation from murine hippocampal sections is unaffected by acetylcholine. It is postulated that the bladder micturition reflex responds to acetylcholine through its immediate cholinergic activity rather than by its influence on serotonin release. These pathways are a promising target for the design of de novo therapeutic agents.

The Effect of Bortezomib on Expression of Inflammatory Cytokines and Survival in a Murine Sepsis Model Induced by Cecal Ligation and Puncture

PURPOSE: Although the proteasome inhibitor known as bortezomib can modulate the inflammatory process through the nuclear factor-kappa B signaling pathway, the immunomodulatory effect of pre-incubated bortezomib has not been fully evaluated for inflammation by infectious agents. Therefore, we evaluated the effect of bortezomib on the expression of inflammatory cytokines and mediators in macrophage cell lines and on survival in a murine peritonitis sepsis model. MATERIALS AND METHODS: Bortezomib was applied 1 hr before lipopolysaccharide (LPS) stimulation in RAW 264.7 cells. The cecal ligation and puncture (CLP) experiments were performed in C57BL/6J mice. RESULTS: Pre-incubation with bortezomib (25 nM or 50 nM) prior to LPS (50 ng/mL or 100 ng/mL) stimulation significantly recovered the number of viable RAW 264.7 cells compared to those samples without pre-incubation. Bortezomib decreased various inflammatory cytokines as well as nitric oxide production in LPS-stimulated cells. The 7-day survival rate in mice that had received bortezomib at 0.01 mg/kg concentration 1 hr prior to CLP was significantly higher than in the mice that had only received a normal saline solution of 1 mL 1 hr prior to CLP. In addition, the administration of bortezomib at 0.01 mg/kg concentration 1 hr before CLP resulted in a significant decrease in inflammation of the lung parenchyma. Collectively, pretreatment with bortezomib showed an increase in the survival rate and changes in the levels of inflammatory mediators. CONCLUSION: These results support the possibility of pretreatment with bortezomib as a new therapeutic target for the treatment of overwhelming inflammation, which is a characteristic of severe sepsis.

Clinical Comparison of Drug-Eluting Stents and Bare Metal Stents in Large Coronary Arteries / 대한내과학회지

BACKGROUND/AIMS: Drug-eluting stents (DES) are superior to bare metal stents (BMS) in reducing restenosis rates across a wide range of patients and lesion subsets.This study compared the clinical outcomes of DES versus BMS in patients with large coronary arteries (> or = 3.5 mm). METHODS: The study compared 134 patients (59.9 +/- 10.6 years, 90 men, 44 women) who underwent single vessel angioplasty with DESimplantation in large vessels with 115 patients (60.3 +/- 8.9 years, 82 men, 33 women) who received BMS. The clinical outcomes at 12 months were compared between groups. The study end points were major adverse cardiac events (MACE), including cardiac death, nonfatal myocardial infarction, and the need for target vessel and target lesion revascularization. RESULTS: The baseline clinical coronary angiography and procedural characteristics were similar in both groups. The duration of dual antiplatelet therapy was longer in the DES group than in the BMS group (240 +/- 2.7 vs. 348 +/- 1.7 days, p = 0.042). During the 12-month clinical follow-up, MACE were observed in 13 patients (11.3%) with BMS and 12 patients (9.0%) with DES (p = 0.486). CONCLUSIONS: For coronary stents implanted in large coronary arteries, DES seems to be more favorable, although no significant differences were observed in the clinical outcomes between DES and BMS during a 1-year clinical follow-up.

Microarray Analysis of Differentially Expressed Genes in the Brains of Tubby Mice

The tubby mouse is characterized by progressive retinal and cochlear degeneration and late-onset obesity. These phenotypes are caused by a loss-of-function mutation in the tub gene and are shared with several human syndromes, suggesting the importance of tubby protein in central nervous system (CNS) functioning. Although evidence suggests that tubby may act as a transcription factor mediating G-protein coupled receptor (GPCR) signaling, any downstream gene regulated by tubby has yet to be identified. To explore potential target genes of tubby with region-specific transcription patterns in the brain, we performed a microarray analysis using the cerebral cortex and hypothalamus of tubby mice. We also validated the changes of gene expression level observed with the microarray analysis using real-time RT-PCR. We found that expression of erythroid differentiation factor 1 (Erdr1) and caspase 1 (Casp1) increased, while p21-activated kinase 1 (Pak1) and cholecystokinin 2 receptor (Cck2r) expression decreased in the cerebral cortex of tubby mice. In the hypothalamic region, Casp 1 was up-regulated and micro-crystallin (CRYM) was down-regulated. Based on the reported functions of the differentially expressed genes, these individual or grouped genes may account for the phenotype of tubby mice. We discussed how altered expression of genes in tubby mice might be understood as the underlying mechanism behind tubby phenotypes.

Zinc Inhibits Amyloid beta Production from Alzheimer's Amyloid Precursor Protein in SH-SY5Y Cells

Zinc released from excited glutamatergic neurons accelerates amyloid beta (A beta) aggregation, underscoring the therapeutic potential of zinc chelation for the treatment of Alzheimer's disease (AD). Zinc can also alter A beta concentration by affecting its degradation. In order to elucidate the possible role of zinc influx in secretase-processed A beta production, SH-SY5Y cells stably expressing amyloid precursor protein (APP) were treated with pyrrolidine dithiocarbamate (PDTC), a zinc ionophore, and the resultant changes in APP processing were examined. PDTC decreased A beta40 and A beta42 concentrations in culture media bathing APP-expressing SH-SY5Y cells. Measuring the levels of a series of C-terminal APP fragments generated by enzymatic cutting at different APP-cleavage sites showed that both beta- and alpha-cleavage of APP were inhibited by zinc influx. PDTC also interfered with the maturation of APP. PDTC, however, paradoxically increased the intracellular levels of A beta40. These results indicate that inhibition of secretase-mediated APP cleavage accounts -at least in part- for zinc inhibition of A beta secretion.

Heparin Attenuates the Expression of TNF alpha-induced Cerebral Endothelial Cell Adhesion Molecule

Heparin is a well-known anticoagulant widely used in various clinical settings. Interestingly, recent studies have indicated that heparin also has anti-inflammatory effects on neuroinflammation-related diseases, such as Alzheimer's disease and meningitis. However, the underlying mechanism of its actions remains unclear. In the present study, we examined the anti-inflammatory mechanism of heparin in cultured cerebral endothelial cells (CECs), and found that heparin inhibited the tumor necrosis factor alpha(TNF alpha)-induced and nuclear factor kappa B (NF-kappa B)-dependent expression of adhesion molecules, such as intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), which are crucial for inflammatory responses. Heparin selectively interfered with NF-kappa B DNA-binding activity in the nucleus, which is stimulated by TNF alpha. In addition, non-anticoagulant 2,3-O desulfated heparin (ODS) prevented NF-kappa B activation by TNF alpha, suggesting that the anti-inflammatory mechanism of heparin action in CECs lies in heparin's ability to inhibit the expression of cell adhesion molecules, as opposed to its anticoagulant actions.

A case of endobronchial aspergilloma in patient with collapse of right middle lobe / 대한내과학회지

Pulmonary aspergilloma usually results from the ingrowths of the colonized Aspergillus in the damaged bronchial tree, pulmonary cyst or cavities of patients with underlying lung diseases. We experienced a case of endobronchial aspergilloma developed in a healthy female patient with asymptomatic collapse of right middle lobe (RML). She visited our clinic with intermittent hemoptysis for one year. The chest X-ray and HRCT showed severe collapse of the RML and multiple calcifications of peribronchial nodes around the proximal part of RML bronchus. Bronchoscopy revealed an aspergilloma in theorifice of the lateral segmental bronchus of RML. Patient had undergone RML and right lower lobe resection because of recurrent hemoptysis in spite of medical therapy. After surgery patient's symptoms were relieved. We present this unusual case with a review of the literature.

A Case of Recurred Uterine Cervical Cancer Presented as Only Huge Mediastinal Mass / 결핵및호흡기질환

Uterine cervical cancer is the 5(th) most common malignancy in Korean women. With the development of new diagnostic and therapeutic modalities, earlier stage cancers are being diagnosed with longer survival rates being anticipated. Accordingly, recurrent cancers are being encountered more often in clinical practice. Most recurrent uterine cervical cancer patients, have intra-pelvic lesions and adjacent lymph node involvement, while a distant metastasis alone is extremely rare. A mediastinal recurrence of uterine cervical cancer is not common with most manifesting as small lymph node enlargements. We report a case of a 46-year-old woman with recurrent uterine cervical cancer presenting only as a huge mediastinal mass without a local recurrence.

Effect of influenza vaccine on pulmonary function in stable asthma / 천식및알레르기

BACKGROUND: Influenza infection causes significant morbidity and mortality in asthma patients. Accordingly, annual vaccination against influenza is recommended. However, there is concern that vaccination may trigger exacerbations. Colds and insufficient asthma control cause exacerbations, which may be mistaken for vaccine related events. METHODS: We undertook a placebo-controlled crossover study to assess the effect of influenza vaccine on pulmonary function in stable asthma, we enrolled 20 patients, aged 18-65 years, who recorded daily peak flow (PEF), respiratory symptoms, medication, and additional medical consultation for each 2 weeks after placebo and vaccine injection. The primary outcome measure was an exacerbation of lung function within 72h of injection. RESULTS: There was no significant difference in the numbers with falls of more than 20% between vaccine and placebo injection (two vs none, p>0.05). Symptom score, medication doses and additional medical consultation were also indifferent after vaccine and placebo injection. CONCLUSION: The influenza vaccine is safe to administer to adult stable asthmatics.

Inhibition of NF-kappaB Activation Increases Oxygen-Glucose Deprivation-Induced Cerebral Endothelial Cell Death

Increasing evidences suggest that ischemia-induced vascular damage is an integral step in the cascade of the cellular and molecular events initiated by cerebral ischemia. In the present study, employing a mouse brain endothelioma-derived cell line, bEnd.3, and oxygen-glucose deprivation (OGD) as an in vitro stroke model, the role of nuclear factor kappa B (NF-kappaB) activation during ischemic injury was investigated. OGD was found to activate NF-kappaB and to induce bEnd.3 cell death in a time-dependent manner. OGD phosphorylated neither 32 Ser nor 42 Tyr of IkappaBalpha. OGD did not change the amount of IkappaB alpha. The extents of OGD-induced cell death after 8 h, 10 h, 12 h and 14 h of OGD were 10%, 35%, 60% and 85%, respectively. Reperfusion following OGD did not cause additional cell death, indicating no reperfusion injury after ischemic insult in cerebral endothelial cells. Three known as NF-kappaB inhibitors, including pyrrolidine dithiocarbamate (PDTC) plus zinc, aspirin and caffeic acid phenethyl ester (CAPE), inhibited OGD-induced NF-kappaB activation and increased OGD-induced bEnd.3 cell death in a dose dependent manner. There were no changes in the protein levels of bcl-2, bax and p53 which are modulated by NF-kappaB activity. These results suggest that NF-kappaB activation might be a protective mechanism for OGD-induced cell death in bEnd.3.

A Case of Pulmonary Sequestration Diagnosed by Doppler Sonography / 결핵

Pulmonary sequestration is a rare congenital malformation during embryouic development which results in a cystic mass of nonfunctioning lung tissue. A diagnosis of a pulmonary sequestration has traditionally relied upon identifying the pathological arterial vessels by arteriography, computed tomography, and magnetic resonance imaging. We reported a case of pulmonary sequestration diagnosed by Doppler sonography and subsequent CT angiography. A 21-year-old-woman admitted to hospital for an investigation of recurrent pneumonia with left lower chest pain. A doppler ultrasound sonography showed an aberrant blood supply from the descending thoracic aorta to the left lower chest lesion. The pulmonary sequestration was confirmed by the subsequent CT angiograph.

Alcoholic Liver Cirrhosis with Multiple Pulmonary Consolidations / 결핵

Pulmonary nocardiosis is an infrequent but severe infection due to the microorganism, Nocardia spp, which may behave as both an opportunists and as a primary pathogens. Usually nocardiosis is found in patients under immunosuppressive regimens for organ transplans, chemotherapy for a malignancy and corticosteroids. The experience of pulmonary nocardiosis in the medical literature is limited to just case reports, with a few series including extrapulmonary nocardiosis. It is believed that the incidence of this infection has been increasing since 1960. The diagnosis is difficult because of the nonspecific clinical manifestations, the lack of laboratory evidence, and the non-specific radiographic findings. Here, we report a case of pulmonary nocardiasis in a 66 year-old patient with alcoholic liver cirrhosis who has suffered from acutely developed dyspnea and general edema. The nocardia species. was cultured from a specimen obtained by a percutaneous transthoracic needle biopsy.

A case of angioedema associated with eosinophilia induced by bee sting / 천식및알레르기

There have been few reports of manifestations such as vasculitis, nephrosis, neuritis, encephalitis, and serum sickness occuring in a temporal relation to insect stings. Symptoms usually start several days to several weeks after the sting and may last for a long time. Angioedema with eosinophilia induced by bee sting has not reported in medical literature. We report a case of eosinophilia with angioedema induced by bee venom in a 30-year-old woman whom presented with edema of extremities and peripheral blood eosinophilia. The patient had high titer of specific IgE to yellow jacket venom.

A Clinical Review of Acute Respiratory Distress Syndrome (ARDS) Due to Miliary Tuberculosis / 결핵

BACKGROUND: The detection and early elimination of the causes for acute respiratory distress syndrome (ARDS) at the initial stage can result in a more favorable prognosis. Miliary tuberculosis as a cause of the ARDS is quite rare. A diagnosis of miliary tuberculosis is difficult due to the diversity of radiological patterns and non-specific clinical findings, and low sensitivity of sputum examinations for acid-fast bacilli(AFBs). An analysis of the clinical data is the first step in diagnosing these unusual, rare cases. METHODS: In this study the clinical features, laboratory data, radiological findings and diagnostic methods were analyzed in 9 cases with an initial presentation of ARDS due to miliary tuberculosis. The ARDS was defined by the definition of the American-Europian Consensus Conference 1992. RESULTS: The mean age of the patients was 67+/-18 years (F:M=7:2). The chief complaints were dyspnea (5/9), coughing (3/9) and fever(5/9). On a physical examination, fine or coarse crackles were noted(6/9). The ARDS developed on average 6.7 days after the initial respiratory symptoms. The mean PaO2/FiO2 of the patients was 133.5+/-53.4, the number of cases with a WBC <5000/mm3 was 4 out of 9 cases. A platelet count <70,000/mm3 was observed in 2 out of 9 cases, and the serum albumin level was 2.6+/-0.6 g/dL. The initial simple chest PA showed ground glass appearances and consolidation in all cases, However, the miliary nodular densities were observed in only 4 out of the 9 cases. HRCT revealed alveolar densities and a consolidation in 5 out of 6 cases, and miliary nodules in 5 out of 6 cases, The diagnosis of tuberculosis was made by a liver biopsy (4/4, 100% sensitivity), a bone marrow biopsy (1/2, 50% sensitivity), and an open lung biopsy (1/1), the sputum AFB was positive in only 2 out of 9 cases. The patient was treated with INH, RFP, EMB, PZA, and steroids. The survival rate was 55.5%. CONCLUSION: Miliary tuberculosis should be considered as one of the causes for ARDS in areas where there is a high prevalence of tuberculosis. The chief complaints of the patients on admission are dyspnea, fever and coughing without any specific riskfactors. A liver biopsy is particularly useful in ARDS patients with mechanical ventilation to determine the causes of the ARDS if miliary tuberculosis is suspected as being the underlying disease.

Parallel Technique of Endobronchial Balloon Catheter Tamponade for Transient Alleviation of Massive Hemoptysis

Endobronchial balloon tamponade is an alternative method that can be used to control massive hemoptysis. Several different techniques have been used for this purpose. We describe a new parallel method, in which biopsy forceps introduced through a bronchoscope channel is used to grasp a balloon catheter. As the bronchoscope is advanced to the bleeding site, the balloon catheter is pulled into position, and subsequently inflated. There are several advantages of this technique. It needs no specialized catheter or guide wire, the procedure is relatively easy to perform, and applicable to other purposes such as introduction of an additional suction catheter.

Effect of Neuropeptide Y on the Serotonin Release in the Rat Hippocampus / 대한남성과학회지

PURPOSE: Hippocampus contains interneurons where neuropeptide Y is located, but the connectivity of these has not been well studied. Neuropeptide Y may influence the serotonergic nervous system through the interneurons. Serotonergic nerve fibers pass through nearly all areas of the hippocampus. We investigate the effects of Neuropeptide Y on serotonin release from rat hippocampal slices for the better understanding of the effects of neuropeptide Y at the hippocampus. MATERIALS AND METHODS: The hippocampus was obtained from the male rat brain and sliced. The slices were incubated in a buffer containing 0.1 mM [3H]5-hydroxytryptamine (5-HT) for uptake. The release of 5-HT into the buffer during each 10 min period was measured and the radioactivities in each buffer and the tissue were counted using liquid scintillation counter and the results were expressed as a percentage of the total activity. After 50 min from the initiation, neuropeptide Y were administered at 6th and 7th 10 min period, respectively. The changes of 5-HT release were expressed as percent values compared to the 5th 10 min period. RESULTS: A steady release of 5-HT was observed up to 100 min after the rapid release during the first 40 min. The 5-HT release during 10 and 20 min of neuropeptide Y (10 6 M) treatment showed no significant change. CONCLUSIONS: The release of 5-HT was not changed by neuropeptide Y and this results suggest that neuropeptide Y does not influence the serotonergic nervous system through the interneurons.

Effect of N-methyl-D-aspartate on the Serotonin Release in the Rat Hippocampus / 대한비뇨기과학회지

PURPOSE: Glutamate and aspartate are the excitatory amino acid neurotransmitters and NMDA (N-methyl-D-aspartate) is one of their major receptors. NMDA agonist may sti mulate serotonergic nervous system that inhibit the penile erection as well as induce the penile erection. We investigate the effects of NMDA agonist on serotonin release from hippocampus. MATERIALS AND METHODS: The slices of hippocampus were incubated in a buffer con taining 0.1mM [(3)H]5-hydroxytryptamine (5-HT) for uptake in the male rat. The release of 5-HT into the buffer during each 10 minutes period was measured and the radio activities in each buffer and the tissue were counted. After 50 min from the initiation, NMDA agonist were administered at 6th and 7th 10 min period respectively. The changes of 5-HT release were expressed as percent values compared to the 5th 10 min period. Tetrodotoxin was used to determine the possible involvement of interneuron on the action of these neurotransmitters. RESULTS: A steady release of 5-HT was observed up to 100 minutes after the rapid release during the first 40 minutes. Treatment of tetrodotoxin (10(-6)M) did not change the spontaneous release of 5-HT. The 5-HT released during 10 and 20 minutes of NMDA agonist (10(-4M)) treatment significantly higher than those of control group. The increase of 5-HT release by NMDA agonist was blocked by pretreatment with tetro dotoxin. The release of 5-HT was increased by NMDA agonist and this response was blocked by tetrodotoxin. CONCLUSIONS: NMDA agonist increases the release of 5-HT through the activation of the interneurons and these results suggest that NMDA agonist may stimulate the serotonergic nervous system that inhibit the penile erection as well as inducing the penile erection.

Effect of Alpha-2 Receptor Blocker on Serotonin Release in Rat Hippocampal Slices / 대한남성과학회지

PURPOSE: It is known that alpha-2 receptor is found at the presynaptic serotonergic nervous system and a consequence of increased activation of alpha-2 receptor decreases the serotonin release. So Alpha-2 blockers may have the effect on the release of serotonin. The major serotonergic innervation is found at the hippocampus. This study was performed to investigate the effect of the alpha-2 receptor blocker to serotonin release in rat hippocampus. MATERIALS AND METHODS: The hippocampus from the male rat brain was sliced. After 30 minutes preincubation in the normal buffer, the slices were incubated for 20 minutes in a buffer containing 0.1 microM[3H]5-HT for uptake, and washed. After administration of alpha 2 receptor blockers, yohimbine (10-5M), the release of [3H]5-HT into the buffer was measured, the radioactivities in each buffer and the tissue were counted and the results were expressed as a percentage of the total activity. The value of released [3H]5-HT was expressed as percent of the value at 50 minutes when a steady state of [3H]5-HT release was obtained. RESULTS: After adminstration of yohimbine (10-5M), the values(mean+/-SE, %) were 147.5+/-9.2 at 60 minutes and 143.8+/-7.3 at 70 minutes compared to the values of control group, 96.6+/-1.9 at 60 minutes and 89.6+/-2.3 at 70 minutes. The release was increased significantly after adminstration of yohimbine. CONCLUSIONS: Alpha-2 receptor blockers increased the release of serotonin. It is suggested that the consideration of the increase of serotonin release by alpha-2 receptor blockers may be helpful to understand the effect of serotonin on sexual function.

Effect of Alpha Adrenergic Drug on Serotonin Release in Rat Hippocampal Slices / 대한비뇨기과학회지

PURPOSE: Peripheral adrenergic nervous system controls the penile erection and alpha adrenoceptors greatly outnumber beta adrenoceptors. It is known that adrenaline has a facilitatory effect but serotonin has an inhibitory effect on sexual drive centrally. But few about the effect of central alpha adrenergic drug to the release of serotonin centrally are known. Major adrenergic and serotoninergic innervation is found at the hippocampus. This study was performed to investigate the effect of alpha adrenergic drugs on serotonergic nervous system in rat hippocampal slices. MATERIALS AND METHODS: The hippocampus from the male rat brain was sliced. After 30 minutes` preincubation in the normal buffer, the slices were incubated for 20 minutes in a buffer containing 0.1 microM [3H]5-hydroxytryptamine(5-HT) for uptake, and washed. After administration of phenylephrine or clonidine, the release of [3H]5-HT into the buffer was measured and the radioactivities in each buffer and the tissue were counted and the results were expressed as a percentage of the total activity. The value of released [3H]5-HT was expressed as percent of the value at 50 minutes when a steady state of [3H]5-HT release was obtained. RESULTS: After administration of phenylephrine(10-5 M), clonidine(10-5 M), the values(mean+/-SE) were 133.4+/-7.3, 103.0+/-0.3 at 60 minutes and 128.8+/-4.6, 100.4+/-4.1(%) at 70 minutes compared to the values of control group, 96.6+/-1.9 % at 60 minutes and 89.6+/-2.3% at 70 minutes. The release of serotonin was increased significantly after administration of phenylephrine. CONCLUSIONS: It is suggested that alpha-1 adrenergic drugs may increase the release of serotonin and therefore the integration of these two neurotransmitters may be considered.