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1.
Neuroscience ; 259: 126-41, 2014 Feb 14.
Article in English | MEDLINE | ID: mdl-24316474

ABSTRACT

Nobiletin, a polymethoxylated flavonoid found in citrus fruit peel, reportedly improves memory impairment in rodent models. Here we report its effect on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced motor and cognitive deficits. Nobiletin administration (50mg/kg i.p.) for 2 consecutive weeks improved motor deficits seen in MPTP-induced Parkinson model mice by 2weeks, an effect that continued until 2weeks after drug withdrawal. Drug treatment promoted similar rescue of MPTP-induced cognitive impairment at equivalent time points. Nonetheless, nobiletin treatment did not block loss of dopaminergic neurons seen in the MPTP-treated mouse midbrain, nor did it rescue decreased tyrosine hydroxylase (TH) protein levels seen in the striatum or hippocampal CA1 region of these mice. Interestingly, nobiletin administration (50mg/kg i.p.) rescued reduced levels of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) autophosphorylation and phosphorylation at Thr-34 of dopamine- and cAMP-regulated phosphoprotein-32 (DARPP-32) in striatum and hippocampal CA1 to levels seen in sham-operated mice. Likewise, CaMKII- and cAMP kinase-dependent TH phosphorylation was significantly restored by nobiletin treatment. MPTP-induced reduction of dopamine contents in the striatum and hippocampal CA1 region was improved by nobiletin administration (50mg/kg i.p.). Acute intraperitoneal administration of nobiletin also enhanced dopamine release in striatum and hippocampal CA1, an effect partially inhibited by treatment with nifedipine (a L-type Ca(2+) channel inhibitor) or NNC 55-0396 (a T-type Ca(2+) channel inhibitor) and completely abolished by combined treatment with both. Overall, our study describes a novel nobiletin activity in brain and suggests that nobiletin rescues motor and cognitive dysfunction in MPTP-induced Parkinson model mice, in part by enhancing dopamine release.


Subject(s)
Antioxidants/therapeutic use , Cognition Disorders/drug therapy , Cognition Disorders/etiology , Flavones/therapeutic use , Motor Activity/drug effects , Parkinsonian Disorders/complications , Animals , Avoidance Learning/drug effects , Brain/drug effects , Brain/metabolism , Brain/pathology , Calcium Channel Blockers/pharmacology , Disease Models, Animal , Dopamine/metabolism , Dose-Response Relationship, Drug , Drug Interactions , Exploratory Behavior/drug effects , Male , Mice , Mice, Inbred C57BL , Nerve Tissue Proteins/metabolism , Parkinsonian Disorders/pathology , Psychomotor Performance/drug effects , Signal Transduction/drug effects , Signal Transduction/physiology
2.
Eur J Surg Oncol ; 30(7): 750-8, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15296989

ABSTRACT

AIMS: To analyse the results of a single institution experience of combined preoperative radio/chemo-radiotherapy and intraoperative electron-radiation therapy (IORT) for locally advanced rectal cancer and to compare the results with surgery alone retrospectively. METHODS: The study cohort comprised 99 patients with clinical T3-4NxM0 adenocarcinoma of the rectum who had received preoperative radio/chemo-radiotherapy, radical surgery, and IORT [Group I]. Until 1998, 67 patients were treated with radiation only [Group Ia], and after 1999, 32 patients were concurrently given tegafur and uracil (UFT) [Group Ib]. 68 patients with clinical T3-4NxM0 rectal cancer were treated with surgery alone [Group II]. RESULTS: The median follow-up was 67 months in Group I and 83 months in Group II. Local recurrence rate was 2% in Group I, which was significantly lower than 16% in Group II (p=0.002) Both disease-free survival and overall survival in Group I were significantly better than those in Group II (p=0.04, p=0.02, respectively). Sphincter preservation was possible in 78% in Group Ib, which was significantly more than 42% in Group Ia (p=0.002). CONCLUSIONS: The combined preoperative radio/chemo-radiotherapy and IORT for clinical T3-4Nx rectal cancer significantly reduces local recurrence and improves prognosis. Combination of preoperative radiotherapy and oral UFT improves the feasibility of sphincter-preservation.


Subject(s)
Adenocarcinoma/therapy , Neoplasm Recurrence, Local/therapy , Rectal Neoplasms/therapy , Adenocarcinoma/mortality , Adenocarcinoma/pathology , Administration, Oral , Antineoplastic Agents/administration & dosage , Cohort Studies , Combined Modality Therapy , Disease-Free Survival , Female , Humans , Intraoperative Care , Japan/epidemiology , Male , Middle Aged , Neoplasm Recurrence, Local/mortality , Neoplasm Recurrence, Local/pathology , Neoplasm Staging , Preoperative Care , Radiation Dosage , Rectal Neoplasms/mortality , Rectal Neoplasms/pathology , Retrospective Studies , Survival Analysis , Treatment Outcome , Uracil/administration & dosage
3.
Psychopharmacology (Berl) ; 173(3-4): 270-7, 2004 May.
Article in English | MEDLINE | ID: mdl-14740148

ABSTRACT

RATIONALE: No selective antagonists for the effects of MDMA have yet been identified. The structurally-similar, naturally-occurring plant alkaloid nantenine (9,10-methylenedioxy-1,2 dimethoxyaporphine) may represent such a compound. OBJECTIVES: To investigate the capacity of nantenine to block and/or reverse MDMA-induced hyperthermia, lethality, locomotor stimulation, and head twitches in mice, and to compare these actions with those of the selective alpha1 antagonist prazosin and the selective 5-HT2A antagonist M100907. METHODS: Pretreatments of either 10 mg/kg nantenine or 1 mg/kg prazosin were administered 15 min before 32 mg/kg MDMA; core temperature and locomotor stimulation were then monitored via radiotelemetry for at least 3 h. In further hyperthermia studies, 32 mg/kg MDMA was administered first and temperature was allowed to rise for 30 min; 10 mg/kg nantenine, 1 mg/kg prazosin, or 1 mg/kg M100907 was then administered in an attempt to reverse MDMA-induced hyperthermia. In lethality assays, percent lethality was quantified 2 h after MDMA injection in two distinct housing conditions, one or 12 mice per cage, with or without 15 min pretreatments of 10 mg/kg nantenine or 1 mg/kg prazosin. Drug elicited head twitches were quantified for 10 min following administration of either MDMA enantiomer, with and without pretreatments of 1 mg/kg nantenine, 0.1 mg/kg prazosin, or 0.001 mg/kg M100907. RESULTS: Nantenine blocked and rapidly reversed MDMA-induced hyperthermia, attenuated lethality in both housing conditions, and reduced MDMA-induced locomotor stimulation and head twitches in mice. Prazosin blocked, but did not reverse, MDMA-induced hyperthermia, attenuated lethality (more effectively in singly-housed animals), and reduced MDMA-induced locomotor stimulation and head twitches. M100907 did not reverse MDMA-induced hyperthermia, but effectively blocked drug-elicited head twitches. CONCLUSIONS: Nantenine functions as an effective antagonist against a wide range of MDMA-induced effects in mice. The antagonist actions of this compound at serotonin and adrenergic receptors may be differentially implicated across endpoints.


Subject(s)
Aporphines/pharmacology , Behavior, Animal/drug effects , Motor Activity/drug effects , N-Methyl-3,4-methylenedioxyamphetamine/antagonists & inhibitors , Serotonin Agents/pharmacology , Adrenergic alpha-Antagonists/pharmacology , Animals , Aporphines/administration & dosage , Crowding , Dose-Response Relationship, Drug , Fever/chemically induced , Fever/drug therapy , Fever/mortality , Fluorobenzenes/pharmacology , Male , Mice , N-Methyl-3,4-methylenedioxyamphetamine/administration & dosage , N-Methyl-3,4-methylenedioxyamphetamine/chemistry , Piperidines/pharmacology , Prazosin/pharmacology , Serotonin Agents/administration & dosage , Serotonin Agents/chemistry , Serotonin Antagonists/pharmacology , Stereoisomerism
4.
Acta Physiol Scand ; 179(3): 273-80, 2003 Nov.
Article in English | MEDLINE | ID: mdl-14616243

ABSTRACT

AIM: This study was conducted to investigate the mechanism of acidic pH-induced contraction (APIC) with regard to Ca2+ handling using isometric tension recording experiments. RESULTS: Decreasing extracellular pH from 7.4 to 6.5 produced a marked and sustained contraction of spontaneously hypertensive rat (SHR) aorta, that was 128.7 +/- 2.0% of the 64.8 mm KCl-induced contraction. Verapamil, an inhibitor of voltage-dependent Ca2+ channels (VDCC) significantly inhibited the APIC. In Ca2+-deficient solution, sustained contraction induced by acidic pH was abolished completely, while a transient contraction was still observed suggesting the release of Ca2+ from intracellular site. Ryanodine (1 microm), a ryanodine receptor blocker, and 10 microm cyclopiazonic acid (CPA; a sarco/endoplasmic reticulum Ca2+ ATPase inhibitor) abolished the transient contraction induced by acidosis. In normal Ca2+-containing solution, ryanodine significantly decreased the rate of rise as well as maximum level of APIC. Interestingly, ryanodine and CPA showed an additive inhibitory effect with verapamil and the combined treatment of ryanodine or CPA with verapamil nearly abolished the APIC. CONCLUSIONS: It is concluded that acidic pH induces Ca2+ release from ryanodine/CPA-sensitive store of sarcoplasmic reticulum in SHR aorta. This Ca2+ plays an important role in the facilitation of the rate of rise of APIC, as well as contributing to the sustained contraction via a mechanism which is independent of Ca2+ influx through VDCC.


Subject(s)
Aorta, Thoracic/physiopathology , Calcium/metabolism , Muscle Contraction/physiology , Muscle, Smooth, Vascular/physiopathology , Sarcoplasmic Reticulum/metabolism , Acidosis/metabolism , Animals , Aorta, Thoracic/drug effects , Calcium Channel Blockers/pharmacology , Calcium-Transporting ATPases/metabolism , Chelating Agents/pharmacology , Egtazic Acid/pharmacology , Enzyme Inhibitors/pharmacology , Hydrogen-Ion Concentration , Indoles/pharmacology , Male , Muscle Contraction/drug effects , Muscle, Smooth, Vascular/drug effects , Rats , Rats, Inbred SHR , Ryanodine/pharmacology , Verapamil/pharmacology
5.
J Pharm Pharmacol ; 54(2): 257-62, 2002 Feb.
Article in English | MEDLINE | ID: mdl-11848289

ABSTRACT

We isolated eight saponins, a hexacyclic lanosterol tetraglycoside (1), a 27-norlanosterol tetraglycoside (2) and six spirostanol oligoglycosides (3-8), from the plants of the family Liliaceae. In murine leukaemic L1210 cells, saponins 5 and 7 at a concentration of 1 microM showed potent cytotoxic activity and the activities were in the following decreasing order: 5, 7, 1, 3, 2, 8, 4, 6. At a concentration of 10 microM, not only 5 and 7 but also 3 and 8 markedly caused cell death. The flow cytometric analysis indicated that 7 and 8 caused a concentration- and time-dependent apoptosis of L1210 cells (EC50 value = approximately 5 microM). The morphological observation using a light microscope revealed that both 7 and 8 induced shrinkage in cell soma and chromatin condensation, suggesting apoptotic cell death. Moreover, in agarose gel electrophoretic analysis, a typical apoptotic DNA ladder pattern was observed after treatment with both 7 and 8. These results suggest that 7 and 8 caused the death of L1210 cells through the apoptotic process. These compounds may become powerful pharmacological tools for studying the molecular mechanism of apoptosis.


Subject(s)
DNA Fragmentation/drug effects , Liliaceae/chemistry , Saponins/chemistry , Saponins/pharmacology , Animals , Leukemia L1210 , Mice , Plant Extracts/chemistry , Plant Extracts/pharmacology , Rhizome/chemistry , Tumor Cells, Cultured
6.
Eur J Pharmacol ; 432(1): 63-70, 2001 Nov 30.
Article in English | MEDLINE | ID: mdl-11734189

ABSTRACT

We examined the effects of 2,5,6-tribromo-1-methylgramine (TBG), isolated from bryozoan, and its derivative, 5,6-dibromo-1,2-dimethylgramine (DBG), on the contraction of rat aorta. TBG and DBG decreased the high-K(+)-induced increase in muscle contraction and cytosolic Ca(2+) level ([Ca(2+)](i)), respectively. The inhibitory effects of TBG and DBG on high-K(+)-induced contraction were antagonized by increasing the external Ca(2+) concentration or by 1,4-dihydro2,6-dimethyl-5-nitro-4-[2-(trifluoromethyl)phenyl]pyridine-3-carboxylic acid (Bay k8644). The high-K(+)-induced increase of Mn(2+) influx was completely blocked by 10 microM TBG or 10 microM DBG. In the Ca(2+)-free solution, 30 microM TBG or 30 microM DBG inhibited the phenylephrine-induced transient increase in [Ca(2+)](i) and muscle tension, while scarcely affecting caffeine-induced transient changes. TBG and DBG significantly increased the cyclic AMP content at 30 microM, but not at 10 microM. These results suggest that TBG and DBG inhibit the smooth muscle contraction by inhibiting Ca(2+) entry, and at higher concentrations, the increase in intracellular cyclic AMP content also contributes to their inhibitory effect.


Subject(s)
Alkaloids/pharmacology , Aorta, Thoracic/drug effects , Indoles/pharmacology , Sulfonamides , Vasodilation/drug effects , 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology , Alkaloids/chemistry , Animals , Aorta, Thoracic/physiology , Caffeine/pharmacology , Calcium/metabolism , Calcium/pharmacology , Calcium Channel Agonists/pharmacology , Dose-Response Relationship, Drug , In Vitro Techniques , Indole Alkaloids , Isoquinolines/pharmacology , Male , Phenylephrine/pharmacology , Potassium/pharmacology , Rats , Rats, Wistar , Time Factors , Vasoconstriction/drug effects , Vasoconstrictor Agents/pharmacology
7.
Eur J Pharmacol ; 432(2-3): 135-42, 2001 Dec 07.
Article in English | MEDLINE | ID: mdl-11740948

ABSTRACT

Bradykinin induced prostaglandin E(2) release from the Swiss 3T3 fibroblasts, preconditioned with fresh culture medium. Although treatment with genistein for the entire period of preconditioning and incubation with bradykinin attenuated prostaglandin E(2) release, treatment with fresh culture medium and genistein for only the preconditioning period further augmented the prostaglandin E(2) release. In the cells preconditioned with fresh culture medium and genistein, bradykinin caused the phosphorylation of protein tyrosine and mitogen-activated protein kinase/extracellular-regulated kinase (MAPK/ERK), followed by arachidonic acid release. Interestingly, preconditioning with genistein alone also caused phosphorylation and arachidonic acid release, probably reflecting rebound activation after the washout of genistein. However, preconditioning with genistein alone induced neither the augmentation of prostaglandin E(2) release nor the expression of cyclooxygenase-2. The further potentiation of bradykinin-induced prostaglandin E(2) release by combined preconditioning with fresh culture medium and genistein may be due to the activation of the MAPK/ERK-c phospholipase A(2) pathway by preconditioning with genistein.


Subject(s)
Dinoprostone/metabolism , Genistein/pharmacology , 3T3 Cells , Animals , Arachidonic Acid/metabolism , Culture Media/pharmacology , Cyclooxygenase 1 , Cyclooxygenase 2 , Dose-Response Relationship, Drug , Immunoblotting , Isoenzymes/drug effects , Isoenzymes/metabolism , Membrane Proteins , Mice , Mitogen-Activated Protein Kinases/metabolism , Phosphorylation/drug effects , Prostaglandin-Endoperoxide Synthases/drug effects , Prostaglandin-Endoperoxide Synthases/metabolism , Protein-Tyrosine Kinases/metabolism , Tyrosine/metabolism
8.
Dis Colon Rectum ; 44(11): 1689-95, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11711743

ABSTRACT

PURPOSE: Intraoperative radiotherapy has been used for local control of locally advanced rectal cancer. The aim of this study was to investigate the efficacy of intraoperative radiotherapy for curatively resected rectal cancer. METHODS: Between 1982 and 1998, intraoperative radiotherapy was administered in combination with curative resection in 78 patients with adenocarcinoma of the middle or lower third of the rectum (intraoperative radiotherapy group). Sixty-two of the patients had received preoperative radiotherapy with 20 Gy. Intraoperative radiotherapy was performed by a new strategy in which an electron beam was administered as uniformly as possible to the entire dissected surface of the pelvis. Retrospective comparisons were made with 248 patients treated by surgery alone during the same period (non-intraoperative radiotherapy group). RESULTS: The differences in tumor stage or surgical procedures between the two groups were not statistically significant. Survival, disease-free survival, and local recurrence-free survival in the intraoperative radiotherapy group were significantly more favorable than in the non-intraoperative radiotherapy group (P = 0.01, P = 0.04, and P = 0.02). Differences in survival were observed in Stage II patients but not in Stage I or Stage III patients. The local failure rate was 2.6 percent in the intraoperative radiotherapy group and 11.3 percent in the non-intraoperative radiotherapy group, and the difference was significant (P = 0.02). The distant metastasis rate was 18.0 percent in the intraoperative radiotherapy group and 19.5 percent in the non-intraoperative radiotherapy group, and the difference was not significant. There was a significantly higher rate of wound infection in the intraoperative radiotherapy group, but no infections were serious. CONCLUSIONS: In patients with adenocarcinoma of the middle or lower third of the rectum, intraoperative radiotherapy to the entire dissected surface of the pelvis reduced local recurrence in Stage II and Stage III patients and improved survival in Stage II patients.


Subject(s)
Adenocarcinoma/radiotherapy , Adenocarcinoma/surgery , Rectal Neoplasms/radiotherapy , Rectal Neoplasms/surgery , Adenocarcinoma/pathology , Adult , Aged , Combined Modality Therapy , Disease-Free Survival , Electrons/therapeutic use , Female , Follow-Up Studies , Humans , Intraoperative Period , Male , Middle Aged , Neoplasm Recurrence, Local , Rectal Neoplasms/pathology
9.
Eur J Pharmacol ; 425(3): 211-8, 2001 Aug 17.
Article in English | MEDLINE | ID: mdl-11513840

ABSTRACT

The pharmacological properties of geissoschizine methyl ether, isolated from Uncaria sinensis Oliv., were analyzed in vitro and in vivo using mice central serotonin neurons. In the in vitro experiment, geissoschizine methyl ether inhibited [3H]8-hydroxy-2-(di-n-propylamino)tetralin) ([3H]8-OH-DPAT) (K(i)=0.8 microM), [3H]mesulergine (K(i)=0.9 microM) and [3H]ketanserin (K(i)=1.4 microM), but had less affinity toward [3H]prazosin (K(i) > 10 microM) and [3H]spiperone (K(i) >15 microM) binding to mouse brain membranes. The in vivo studies showed that geissoschizine methyl ether dose-dependently reduced 5-hydroxy-L-tryptophan (I-5-HTP) plus clorgyline-induced head twitch response without inhibiting the I-5-HTP plus clorgyline and 8-OH-DPAT-induced head weaving. On the other hand, geissoschizine methyl ether also decreased the rectal temperature of mice (hypothermic response) in a dose-dependent manner. These results suggest that geissoschizine methyl ether possesses mixed 5-HT(1A) receptor agonist/5-HT(2A/2C) receptor antagonist activities and inhibits the head twitch response by blocking the 5-HT(2A) receptors, and possibly, at least in part, by stimulating the 5-HT(1A) receptors in the central nervous system.


Subject(s)
Central Nervous System/drug effects , Drugs, Chinese Herbal/pharmacology , Indoles/pharmacology , 5-Hydroxytryptophan/pharmacology , 8-Hydroxy-2-(di-n-propylamino)tetralin/metabolism , 8-Hydroxy-2-(di-n-propylamino)tetralin/pharmacology , Animals , Behavior, Animal/drug effects , Binding, Competitive/drug effects , Body Temperature/drug effects , Brain/drug effects , Brain/metabolism , Dose-Response Relationship, Drug , Drug Synergism , Indole Alkaloids , Male , Membranes/drug effects , Membranes/metabolism , Mice , Motor Activity/drug effects , Radioligand Assay , Rectum/physiology , Tritium
10.
Chem Pharm Bull (Tokyo) ; 49(7): 912-4, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11456102

ABSTRACT

The aerial part of Aster scaber Thunb. (Asteraceae) yielded two new monoterpene peroxide glycosides, (3S)-3-O-(3',4'-diangeloyl-beta-D-glucopyranosyloxy)-7-hydroperoxy-3,7-dimethylocta-1,5-diene (1) and (3S)-3-O-(3',4'-diangeloyl-beta-D-glucopyranosyloxy)-6-hydroperoxy-3,7-dimethylocta-1,7-diene (2), and five known compounds, alpha-spinasterol (3), germacra-4(15),5,10(14)-triene-1-beta-ol (4), 7-methoxy-4(15)-oppositen-1-beta-ol (5), 6alpha-methoxy-4(15)-eudesmane-1beta-ol (6) and alpha-spinasterol 3-O-beta-D-glucopyranoside (7). The structures were established by chemical and spectroscopic methods.


Subject(s)
Asteraceae/chemistry , Glucosides/chemistry , Monoterpenes , Plants, Medicinal/chemistry , Carbohydrate Sequence , Chromatography, Thin Layer , Glucosides/isolation & purification , Hydrolysis , Korea , Magnetic Resonance Spectroscopy , Mass Spectrometry , Molecular Conformation , Molecular Sequence Data , Oxidation-Reduction
11.
J Nat Prod ; 64(6): 806-8, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11421751

ABSTRACT

A novel dimeric dihydrochalcone, verbenachalcone (1), was isolated from the aerial parts of Verbena littoralis. Its structure was elucidated, on the basis of spectral data interpretation, as 4,2',4',2' ",4' "-pentahydroxy-3' '-methoxy-3-O-4' '-tetrahydrobichalcone. This compound caused a significant enhancement of nerve growth factor-mediated neurite outgrowth from PC12D cells.


Subject(s)
Chalcone/chemistry , Nerve Growth Factor/pharmacology , Plants, Medicinal/chemistry , Animals , Cells, Cultured , Chalcone/analogs & derivatives , Chalcone/pharmacology , Chalcones , Drug Synergism , Neurites/drug effects , Neurons/drug effects , Paraguay , Spectrophotometry, Infrared
12.
J Pharm Pharmacol ; 53(6): 915-9, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11428671

ABSTRACT

In PC12D cells, nerve growth factor (NGF) increased the proportion of neurite-bearing cells and made neurites longer. A methanol extract of Verbena littoralis H. B. K. collected in Paraguay only slightly potentiated the proportion of PC12D cells with neurites but markedly increased the length of neurites in the presence of NGF (2 ng mL(-1)). The methanol extract was partitioned between ethyl acetate and water followed by further extraction of water fraction with n-butanol. The potentiating activity of NGF-action was observed in the ethyl acetate and n-butanol fractions. The n-butanol fraction was separated by silica gel chromatography, monitoring the NGF-potentiating activity to give gelsemiol and 9-hydroxysemperoside aglucone (9-OHSA). Neither compound (30-300 microM) exhibited neurite-inducing activity alone. Gelsemiol (100-300 microM) markedly enhanced an increase in the proportion of neurite-bearing cells and an extension of the neurite length in the presence of NGF (2 ng mL(-1)). Interestingly, in the presence of NGF (2 ng mL(-1)), 9-OHSA (100-300 microM) enhanced the elongation of neurites without affecting the increase in the proportion of cells with neurites. These results suggested that gelsemiol and 9-OHSA were major active components of V. littoralis in the NGF-potentiating action. It was possible that the mechanism of neurite elongation by NGF was different from that of the increase in the proportion of neurite-bearing cells, and that 9-OHSA selectively affected the neurite elongation mechanism.


Subject(s)
Gelsolin/pharmacology , Nerve Growth Factor/pharmacology , Neurites/drug effects , Plant Extracts/pharmacology , Cell Culture Techniques , Chromatography, High Pressure Liquid , Gelsolin/isolation & purification , Heterocyclic Compounds, 3-Ring/isolation & purification , Heterocyclic Compounds, 3-Ring/pharmacology , Humans , Methanol/chemistry , Neurites/ultrastructure
13.
Jpn J Pharmacol ; 85(4): 382-90, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11388642

ABSTRACT

Ca2+ release by caffeine and 9-methyl-7-bromoeudistomin D (MBED) and the concomitant activation of large conductance Ca2+-dependent K+ (BK) channels were analyzed using confocal Ca2+ imaging and whole cell voltage-clamp methods in guinea pig urinary bladder smooth muscle cells. Puff application of 3 or 10 mM caffeine for several seconds (2 - 5 s) elicited a large increase in intracellular Ca2+ concentration ([Ca2+]i) and induced a phasic outward current at a holding potential of -40 mV. The phasic outward current was the summation of spontaneous transient outward currents (STOCs) due to marked activation of BK channels and was followed by a short cessation of STOCs. Although the increase in superficial [Ca2+]i by caffeine was faster than that in global [Ca2+]i, the peak [Ca2+]i was identical in these areas. Puff application of 100 microM MBED also markedly enhanced STOCs for a few seconds. This response to MBED was not observed when stored Ca2+ was depleted by caffeine. The increase in [Ca2+]i by MBED occurred mainly in superficial areas. Longer application of 100 microM MBED for 2 min did not induce significant global [Ca2+]i increase but decreased the amount of Ca2+ release and cell shortening during the subsequent application of 10 mM caffeine. These results indicate that short application of MBED releases Ca2+ preferentially from superficial storage sites, presumably due to its slow approach to deeper sites. MBED may be a good pharmacological tool to manipulate selectively the superficial Ca2+ stores related to STOCs.


Subject(s)
Caffeine/pharmacology , Calcium/metabolism , Muscle, Smooth/cytology , Muscle, Smooth/drug effects , Potassium Channels/metabolism , Urinary Bladder/cytology , Animals , Calcium/physiology , Carbolines/pharmacology , Guinea Pigs , Male , Microscopy, Confocal , Muscle, Smooth/metabolism , Patch-Clamp Techniques , Phosphodiesterase Inhibitors/pharmacology , Urinary Bladder/drug effects , Urinary Bladder/metabolism
14.
Mol Pharmacol ; 59(5): 1287-97, 2001 May.
Article in English | MEDLINE | ID: mdl-11306714

ABSTRACT

Glial cells release neurotrophic factors that maintain neurons functionally. Previously, we have shown that the scabronines isolated from Sarcodon scabrosus enhanced the secretion of neurotrophic factors from 1321N1 human astrocytoma cells. In the present study, we examined the mechanism of newly synthesized scabronine G-methylester (ME)-induced secretion of neurotrophic factors from 1321N1 cells. The dramatic neuronal differentiation of rat pheochromocytoma cells (PC-12) was observed by scabronine G-ME-conditioned medium of 1321N1 cells. Scabronine G-ME increased the secretion of nerve growth factor (NGF) and interleukin-6 (IL-6) from 1321N1 cells with the enhancement of their mRNA expressions. Scabronine G-ME concentration-dependently inhibited the carbachol-induced inositol phosphate accumulation in 1321N1 cells, which was reversed by GF109203X, an inhibitor of protein kinase C (PKC) isoforms. Furthermore, GF109203X inhibited the scabronine G-ME-induced mRNA expressions of both NGF and IL-6 and the differentiation of PC-12 cells, showing that scabronine G-ME activated PKC. Although scabronine G-ME enhanced activities of neither conventional nor novel types of PKCs, it translocated PKC-zeta to membranes in intact cells and cell-free condition. Furthermore, recombinant PKC-zeta activity was also increased by scabronine G-ME, suggesting the involvement of PKC-zeta in the effect of scabronine G-ME. Concerning the downstream effectors of the PKC-zeta, scabronine G-ME translocated nuclear factor-kappaB to nucleus, and enhanced its transcriptional activity. In addition, scabronine G-ME caused the degradation of inhibitor of nuclear factor-kappaB concentration-dependently, which was inhibited by GF109203X. These results suggest that scabronine G-ME potentially enhances the secretion of neurotrophic factors from 1321N1 cells mediated via the activation of PKC-zeta.


Subject(s)
Diterpenes/pharmacology , Nerve Growth Factors/metabolism , Protein Kinase C/metabolism , Animals , Cell Differentiation/drug effects , Diterpenes/chemistry , Enzyme Activation/drug effects , Humans , NF-kappa B/metabolism , Nerve Growth Factors/biosynthesis , PC12 Cells , Rats , Tumor Cells, Cultured
17.
Eur J Pharmacol ; 413(1): 37-45, 2001 Feb 09.
Article in English | MEDLINE | ID: mdl-11173061

ABSTRACT

In nerve growth factor-treated PC12 cells, 12b-methyl-(S)-1H-benzo[6,7]phenanthro[10,1-bc]furan-3,6,8,11(2H,12bH)-tetrone (halenaquinone) caused cytotoxicity in a concentration-dependent manner (EC(50) value; 10 microM). Gel electrophoretic DNA analysis of PC12 cells treated with halenaquinone (10 microM) and 11-(acetyloxy)-1,6b,7,8,9a,10,11,11b-octahydro-1-(methoxymethyl)-9a,11b-dimethyl-[1S-(1 alpha,6b alpha,9a beta,11 alpha,11b beta)]-3H-furo[4,3,2-de]indeno[4,5-h]-2-benzopyran-3,6,9-trione (wortmannin) (3 microM) showed a typical apoptotic DNA ladder. In the flow cytometric analysis, halenaquinone caused apoptosis in a concentration- and time-dependent manner (EC(50) value; 10 microM), whereas 2,3-dihydro-12b-methyl-(S)-1H-benzo[6,7]phenanthro[10,1-bc]furan-6,8,11(12bH)-trione (xestoquinone) with the methylene group at the C-3 position failed to cause apoptosis, suggesting that the carbonyl group at the C-3 position in halenaquinone is important for exerting apoptotic effects in PC12 cells. Phosphatidylinositol 3-kinase was inhibited by halenaquinone (IC(50) value; 3 microM) as well as wortmannin, a specific inhibitor of phosphatidylinositol 3-kinase. Halenaquinone inhibited phosphatidylinositol 3-kinase activity at lower concentrations than those at which it induced apoptosis in PC12 cells. These results suggest that halenaquinone causes the death of PC12 cells through an apoptotic process and that the mechanism of halenaquinone-induced apoptosis may be partially explained by the inhibition of phosphatidylinositol 3-kinase activity.


Subject(s)
Apoptosis/drug effects , Phosphoinositide-3 Kinase Inhibitors , Protein Serine-Threonine Kinases , Quinones/pharmacology , Acetylcysteine/pharmacology , Androstadienes/chemistry , Androstadienes/pharmacology , Animals , Blotting, Western , Cell Size/drug effects , Cell Survival/drug effects , DNA Fragmentation/drug effects , Flow Cytometry , Microscopy, Fluorescence , Microscopy, Phase-Contrast , Nerve Growth Factor/pharmacology , PC12 Cells , Phosphatidylinositol 3-Kinases/metabolism , Phosphorylation/drug effects , Porifera , Precipitin Tests , Proto-Oncogene Proteins/metabolism , Proto-Oncogene Proteins c-akt , Quinones/chemistry , Rats , Wortmannin
18.
Can J Physiol Pharmacol ; 79(12): 1030-5, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11824938

ABSTRACT

We previously showed that zooxanthellatoxin-B, isolated from dinoflagellate, caused a sustained contraction of the aorta in an external Ca2+-dependent manner. To clarify the role of Ca2+ in this action, we examined the effects of zooxanthellatoxin-B as well as a depolarizing stimulus (60 mM KCl), using the simultaneous recording for cytosolic Ca2+ level (fura-2) and developed tension in the rabbit aorta. KCl (60 mM) elicited a rapid cytosolic Ca2+ elevation followed by a pronounced contraction, and time required for half-maximum contraction was 2 min. Zooxanthellatoxin-B caused an increase in cytosolic Ca2+ followed by a gradual contraction, with a time for half-maximum contraction of 5-10 min in a concentration-dependent manner. We found a strong correlation between Ca2+ elevation and the contraction in zooxanthellatoxin-B action. In a Ca2+-free solution, zooxanthellatoxin-B caused neither the contraction nor the increase in cytosolic Ca2+. Furthermore, both pre- and post-treatment with verapamil, a voltage-operated Ca2+-channel blocker, partially suppressed both an increase in cytosolic Ca2+ and the contraction by zooxanthellatoxin-B. Zooxanthellatoxin-B-induced contraction was also inhibited by other voltage-operated Ca2+-channel blockers: nifedipine or diltiazem. These results suggest that zooxanthellatoxin-B-elicited contraction is caused by a Ca2+ influx into the smooth muscle cells, partially via voltage-operated Ca2+ channels.


Subject(s)
Aorta, Thoracic/drug effects , Aorta, Thoracic/metabolism , Calcium/metabolism , Eukaryota/chemistry , Marine Toxins/pharmacology , Muscle, Smooth, Vascular/drug effects , Polyenes/pharmacology , Vasoconstrictor Agents/pharmacology , Animals , Calcium Channel Blockers/pharmacology , Cytosol/drug effects , Cytosol/metabolism , In Vitro Techniques , Male , Muscle Contraction/drug effects , Rabbits
19.
Can J Physiol Pharmacol ; 79(11): 953-8, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11760098

ABSTRACT

Two steroidal saponins, tigogenin hexasaccharide-1 (TGHS-1, (25R)-5alpha-spirostan-3beta-yl 4-O-[2-0-[3-O-(alpha-L-rhamnopyranosyl)-beta-D-glucopyranosyl]-3-0-[4-0- (alpha-L-rhamnopyranosyl)-beta-D-glucopyranosyl]-beta-D-glucopyranosyl]-3-D- galactopyranoside) and tigogenin hexasaccharide-2 (TGHS-2, (25R)-5alpha-spirostan-3beta-yl 4-O-[2-0-[3-0-(beta-D-glucopyranosyl)-beta-D-glucopyranosyl]-3-0-[4-0- (alpha-L-rhamnopyranosyl)-beta-D-glucopyranosyl]-beta-D-glucopyranosyl]beta-D-galactopyranoside), were isolated from the fresh bulbs of Camassia cusickii. In murine leukemic L1210 cells, both compounds showed cytotoxicity with an EC50 value of 0.06 microM. The morphological observation revealed that TGHS-1 and TGHS-2 induced shrinkage in cell soma and chromatin condensation, suggesting apoptotic cell death. The cell death was confirmed to be apoptosis by Annexin V binding to phosphatidylserine in the cell membrane and excluding propidium iodide. A typical apoptotic DNA ladder and the cleavage of caspase-3 were observed after treatment with TGHS-1 and TGHS-2. In the presence of both the compounds, cells with sub-G1 DNA content were detected by flow cytometric analysis, indicating that TGHS-1 and TGHS-2 (each EC50 value of 0.1 microM) are the most powerful apoptotic saponins known. These results suggest that TGHS-1 and TGHS-2 induce apoptotic cell death through caspase-3 activation.


Subject(s)
Apoptosis , Liliaceae , Saponins/pharmacology , Spirostans/pharmacology , Animals , Blotting, Western , Cell Separation , DNA Fragmentation , Electrophoresis, Agar Gel , Flow Cytometry , Leukemia L1210 , Mice , Plant Structures , Saponins/isolation & purification , Spirostans/isolation & purification , Tumor Cells, Cultured
20.
Tokai J Exp Clin Med ; 25(2): 61-7, 2000 Jun.
Article in English | MEDLINE | ID: mdl-11127509

ABSTRACT

UNLABELLED: The effects of hyperthermia combined with re-irradiation were compared with those of reirradiation alone using retrospectively matched-pair analysis. Between 1984 and 1997, 12 patients were treated with hyperthermia combined with re-irradiation for neck node metastasis from squamous cell carcinoma of the head and neck. During the same period, 12 patients treated with re-irradiation alone were selected retrospectively using the same anatomical diagnosis, nodal site, and nodal size. Recurrent nodes were heated by a 2450MHz microwave or 13MHz radio frequency 4 times on average for 30 to 50 min immediately before radiotherapy. The maximum temperatures were >41degrees C in 83% and >42 degrees C in 58% of patients. RESULTS: The median survival and median recurrence periods were 12 months and 6 months, respectively in both groups. The response rate was 83% in both groups. Nodal size and radiation dose, but not heating temperature, were prognostic factors. Five patients in the hyperthermia group experienced skin ulcers or burns as acute complications. Late complications were observed in one patient in the hyperthermia group and 3 patients in the re-irradiation-alone group. CONCLUSION: Heating induced acute complications and had no significant effect on the tumors. Further advances in hyperthermic technique are required.


Subject(s)
Head and Neck Neoplasms/therapy , Hyperthermia, Induced , Lymphatic Irradiation , Combined Modality Therapy , Female , Head and Neck Neoplasms/mortality , Head and Neck Neoplasms/pathology , Humans , Lymphatic Metastasis , Male , Matched-Pair Analysis , Middle Aged , Prognosis , Retrospective Studies , Survival Rate
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