Different circulating levels of monocyte chemoattractant protein-1 and interleukin-8 during the menopausal transition.

OBJECTIVE: The aim of the present study was to clarify the changes in circulating cytokines and chemokines in women during the menopausal transition by using a detailed classification. MATERIALS AND METHODS: A total of 554 women were recruited for this study from the outpatient clinic of the Department of Obstetrics and Gynecology, Tokushima University Hospital. We divided the women into seven stages by menstrual regularity and FSH level: mid-reproductive stage, late reproductive stage, early menopausal transition, late menopausal transition, very early postmenopause, early postmenopause and late postmenopause. We measured serum concentrations of nine cytokines (IL-1ß, IL-5, IL-6, IL-7, IL-8, IL-10, TNF-α, MIP-1ß and MCP-1). RESULTS: Serum IL-8 concentrations in postmenopausal women were significantly (p = 0.001) higher than those in women in the mid- or late reproductive stage and women in early or late menopausal transition. Serum MCP-1 levels in women in late menopausal transition and postmenopause were significantly (p < 0.001) higher than those in women in the mid- or late reproductive stage and women in early menopausal transition. MCP-1 level showed a significant positive correlation (r = 0.215, p < 0.01) with FSH level in women in menopausal transition. CONCLUSION: By using a detailed classification of menopausal transition, patterns of changes in IL-8 and MCP-1 levels during the menopausal transition were found to be different. IL-8 level showed a high level after menopause, while MCP-1 level showed a high level in menopausal transition. MCP-1 may be sensitive to hormonal change and may be involved in the development of estrogen deficiency diseases.

Antiallodynic effect of herbal medicine yokukansan on peripheral neuropathy in rats with chronic constriction injury.

Yokukansan, one of the traditional Japanese herbal medicines, ameliorated neuropathic pain symptoms in patients. In this study, we investigated the effects of yokukansan on neuropathic pain in chronic constriction injury (CCI) model. Oral administration of yokukansan significantly inhibited mechanical and cold allodynia in the von Frey hair or acetone test, respectively. In comparison, amitriptyline, a tricyclic antidepressant, demonstrated moderate, but not significant, antiallodynic effects in the mechanical and cold tests. Yokukansan significantly inhibited the cerebrospinal fluid dialysate level of glutamate that had increased by the stimulation of brush or acetone. Glutamate transporter inhibitors, DL-threo-beta-hydroxy aspartate and dihydrokainate, decreased the yokukansan-induced antiallodynic actions in CCI rats. Our results suggest that yokukansan was confirmed to have antiallodynic effects in CCI rats, which are related to a blockade of glutamatergic neurotransmission via activation of glutamate transporters in the spinal cord.

Changes in circulating cytokine levels in midlife women with psychological symptoms with selective serotonin reuptake inhibitor and Japanese traditional medicine.

OBJECTIVE: The aim of the present study was to compare the effects on serum cytokine concentrations of paroxetine, a selective serotonin re-uptake inhibitor, and kamishoyosan, a Japanese traditional medicine, in midlife women with psychological symptoms. METHODS: Seventy-six women with psychological symptoms such as anxiety and mild depression as menopausal symptoms were enrolled in this study. Thirty-eight women received oral administration of 10mg paroxetine every day, and 38 women received oral administration of kamshoyosan every day for 6 months. Overall climacteric symptoms were assessed using Greene's climacteric scale. Serum levels of cytokines were measured using a multiplexed human cytokine assay. RESULTS: Greene's total scores in both women treated with paroxetine and in women treated with kamishoyosan decreased significantly. Percentage decreases in Greene's total, psychological and vasomotor scores during the 6-month period in the paroxetine group were significantly greater than those in the kamishoyosan group. Serum IL-6 concentration in women treated with paroxetine decreased significantly. Serum concentrations of IL-8, IL-10, macrophage inflammatory protein (MIP)-1beta and monocyte chemoattractant protein-1 in women treated with paroxetine decreased significantly. On the other hand, serum IL-6 concentration in women treated with kamishoyosan decreased significantly, but other serum concentrations did not change significantly. CONCLUSION: Decrease in IL-6 concentration may be involved in the mechanism of the actions of both paroxetine and kamishoyosan in women with psychological symptoms, and IL-6 may therefore be useful as a marker of treatment. The action of paroxetine may also be associated with decreases in IL-8, IL-10, MIP-1beta.

Effects of yokukansan, a traditional Japanese medicine, on memory disturbance and behavioral and psychological symptoms of dementia in thiamine-deficient rats.

Effects of yokukansan (TJ-54) on memory disturbance and behavioral and psychological symptoms of dementia (BPSD) were investigated in thiamine-deficient (TD) rats which were produced by feeding a TD diet for 37 d. Daily oral administration of TJ-54 (0.5, 1.0 g/kg) ameliorated the memory disturbance, anxiety-like behavior, the increase in aggressive behaviors, the decrease in social behaviors, and several neurological symptoms including opisthotonus observed in TD rats, in a dose-dependent manner. In addition, histopathological examinations showed that TJ-54 inhibited the degeneration of neuronal and astroglial cells in the brain stem, hippocampus and cortex in TD rats. Microdialysis experiments showed that TJ-54 inhibited extracellular glutamate rise in the ventral posterior medial thalamus in TD rats. These results suggest that TJ-54 possesses the preventive or progress inhibitive effect against the development of memory disturbance and BPSD-like behaviors induced by the degeneration of neuronal and astroglial cells resulting from TD. TJ-54 may inhibit glutamate-mediated excitotoxicity as one of mechanisms.

Effect of yokukansan, a traditional Japanese medicine, on social and aggressive behaviour of para-chloroamphetamine-injected rats.

OBJECTIVES: Yokukansan, a traditional Japanese medicine, has been approved by the Ministry of Health, Labour, and Welfare of Japan as a remedy for neurosis, insomnia or night crying and irritability in children. It has recently been reported to improve behavioural and psychological symptoms of dementia, such as hallucinations, agitation, and aggressiveness in patients with some forms of senile dementia. Little is known about the mechanism underlying the effectiveness of yokukansan. Our aim was to clarify the involvement of yokukansan in serotonergic function in para-chloroamphetamine (PCA)-induced aggressive behaviour in rats. METHODS: The effect of yokukansan on social interactions, including social and aggressive behaviour, was examined in PCA-injected rats. Concentration and release level of serotonin (5-HT) in the hypothalamus were measured. KEY FINDINGS: PCA reduced not only the 5-HT concentration but also the high K(+)-induced 5-HT release in the rat hypothalamus. Social interaction tests showed a significant decrease in social behaviour and a significant increase in aggressive behaviour in the PCA-treated rats. The decrease in social behaviour was ameliorated by the 5-HT1A agonist buspirone and further decreased by a 5-HT1A antagonist, N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl)cyclo-hexanecarboxamide trihydrochloride (WAY-100635), whereas it was further decreased by the 5-HT2A agonist, 2,5-dimethoxy-4-iodoamphetamine (DOI), and ameliorated by the 5-HT2A antagonist ketanserin. On the other hand, the increase in aggressive behaviour was ameliorated by buspirone but not affected by WAY-100635, whereas it was enhanced by DOI and ameliorated by ketanserin. A single injection of yokukansan ameliorated the PCA-induced decrease in social behaviour but not aggressive behaviour. Chronic treatment for 14 days with yokukansan ameliorated PCA-induced abnormal behaviour, decreased social behaviour and increased aggressive behaviour, but it did not ameliorate PCA-induced decreases in the cerebral 5-HT concentration and 5-HT release. The ameliorative effects of chronic yokukansan on behaviour were counteracted by co-administration of WAY-100635. CONCLUSIONS: These results suggest that yokukansan might have two different effects: an acute effect on social behaviour and a chronic effect on aggressive behaviour. One of the mechanisms of these effects of yokukansan may be related to the agonistic effect on 5-HT1A receptors.

Involvement of cytokine-induced neutrophil chemoattractant in hypothalamic thermoregulation of luteinizing hormone-releasing hormone.

We demonstrated in a previous study that serum IL-8 concentrations were significantly higher in women with hot flashes than without hot flashes. To clarify the role of IL-8 in the pathoetiology of menopausal hot flashes, we examined the effect of rat cytokine-induced neutrophil chemoattractant (CINC), a member of the IL-8 family, on thermoregulation using ovariectomized (OVX) rats treated with intracerebroventricular (i.c.v.) injection of LHRH agonist (LHRHa) as a model of hot flashes. We found that: 1) expression of CINC mRNA was increased around the periventricular area in the hypothalamus at 1 h, and the serum CINC concentration was increased at 2 h after i.c.v. injection of LHRHa; 2) the increase in serum CINC concentration in hypophysectomized rats was significantly lower than that in sham-operated rats; 3) i.c.v. but not iv injection of CINC elevated the rectal temperature of OVX rats; 4) i.c.v. injection of LHRHa into OVX rats produced a rapid rise (maximal increase: 10-25 min) in tail skin temperature, and the elevation was augmented by injection of an anti-CINC antibody; and 5) changes in serum CINC concentration and skin temperature after i.c.v. injection of LHRHa were reversed by replacement of estradiol. In conclusion, the production of CINC in the hypothalamus due to LHRHa injection in OVX rats was increased after elevation of skin temperature, suggesting that CINC plays a key role in the homeostasis of body temperature. Disturbance of the thermoregulatory mechanism involving LHRH and CINC may be related to the pathoetiology of hot flashes.

Associations of interleukin-6 with interleukin-1beta, interleukin-8 and macrophage inflammatory protein-1beta in midlife women.

OBJECTIVE: The aim of the present study was to determine the associations of interleukin (IL)-6 with other cytokines and chemokines and to compare these associations in peri- and postmenopausal women. METHODS: Ninety-nine perimenopausal and 92 postmenopausal women were enrolled in this study. Serum concentrations of IL-6, IL-1beta, IL-2, IL-4, IL-5, IL-7, IL-8, IL-10, IL-12, IL-13, IL-17, tumor necrosis factor (TNF)-alpha, interferon gamma, granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage (GM)-CSF, macrophage inflammatory protein (MIP)-1beta and monocyte chemotactic protein (MCP)-1 were measured simultaneously using a multiplexed cytokine assay. RESULTS: Among the 17 cytokines, IL-6, IL-1beta, IL-5, IL-7, IL-8, IL-10, MCP-1 and MIP-1beta were detected in serum in more than 50% of the women. Serum levels of IL-4 and MCP-1 in postmenopausal women were significantly higher than those in perimenopausal women. Serum IL-6 concentrations showed significant and positive correlations with serum concentrations of IL-1beta, IL-8, MIP-1beta, IL-7 and MCP-1 in women regardless of menopausal status, and these correlations were still significant after adjustment for age and body mass index. CONCLUSION: Serum IL-6 concentration was found to be closely associated with serum concentrations of IL-1beta, IL-8, MIP-1beta, IL-7 and MCP-1 in women regardless of menopausal status, suggesting that these cytokines act in concert with the progression of several symptoms and various diseases.

Associations of circulating adiponectin with estradiol and monocyte chemotactic protein-1 in postmenopausal women.

OBJECTIVE: The aim of the present study was to clarify the association of serum adiponectin concentrations with serum 17beta-estradiol concentrations in pre-, peri-, and postmenopausal women. In addition, the associations of serum adiponectin with serum concentrations of proinflammatory and anti-inflammatory cytokines were examined in women during the menopausal transition. DESIGN: A total of 197 women were enrolled in this study: 33 premenopausal women, 80 perimenopausal women, and 84 postmenopausal women. Serum adiponectin concentration was measured by an enzyme-linked immunosorbent assay. Serum concentrations of the proinflammatory cytokines interleukin (IL)-1beta, IL-6, and tumor necrosis factor alpha, anti-inflammatory cytokine IL-10, and the chemokines IL-8, macrophage inflammatory protein-1beta and monocyte chemotactic protein-1 were measured by using a multiplexed human cytokine assay. RESULTS: Serum adiponectin concentration showed a significant negative correlation with serum estradiol concentration (r= -0.400, P=0.001) in postmenopausal women but not in pre- and perimenopausal women, and this correlation was significant after adjustment for age and body mass index. Serum adiponectin concentration also showed a significant negative correlation with serum monocyte chemotactic protein-1 concentration (r= -0.244, P=0.05) in postmenopausal women. CONCLUSION: An increase in adiponectin level due to a decrease in estradiol results in a reduction in monocyte chemotactic protein-1 level in postmenopausal women, suggesting that adiponectin may be associated with a protective role against insulin resistance and atherosclerosis, which occur in the postmenopausal stage.

Role of alpha2-adrenoceptors in enhancement of antinociceptive effect in diabetic mice.

The present studies investigated behavioral and neurochemical aspects of the noradrenergic and serotonergic nervous systems in streptozotocin-induced diabetic mice. We previously reported that intrathecal (i.t.) injection of norepinephrine significantly potentiated antinociception in diabetic mice compared to that in non-diabetic mice, and that antinociception due to norepinephrine injection was completely abolished by pretreatment with yohimbine, an alpha2-adrenoceptor antagonist. The present studies demonstrated that i.t. injection of clonidine also showed more-potent antinociceptive activity in diabetic mice than in non-diabetic mice, but that i.t. methoxamine injection did not affect diabetic or non-diabetic mice. The antinociceptive potency due to i.t. injection of 5-HT was significantly lower in diabetic than in non-diabetic mice. In a neurochemical study, we found that the density of [3H]-rauwolscine binding sites in spinal alpha2-adrenoceptors was significantly higher in diabetic than in non-diabetic mice, but that the binding affinity was unchanged. Spinal norepinephrine turnover was determined by measuring the decline in tissue norepinephrine concentration at 3 h after injection of the tyrosine hydroxylase inhibitor alpha-methyl-p-tyrosine. The spinal norepinephrine concentration decreased to 43.7% from the baseline in non-diabetic mice, while it was 21.0% in diabetic mice. These results suggest that, based on the decrease of norepinephrine release in the spinal cord, up-regulation of spinal alpha2-adrenoceptors caused the increase of antinociception due to i.t. injection of an alpha2-adrenoceptor agonist in streptozotocin-induced diabetic mice, and it seemed that the stimulation of alpha2-adrenoceptors potentiated the antinociceptive effect. Thus, the spinal noradrenergic systems play an important moderating role in diabetes-induced neuropathic pain.

Suppressive effect of Yokukansan on excessive release of glutamate and aspartate in the hippocampus of zinc-deficient rats.

Yokukansan (TJ-54), a herbal medicine, has been used as a cure for insomnia and irritability in children. Yokukansan also improves behavioral and psychological symptoms such as agitation, aggression and irritability in patients with dementia including Alzheimer's disease, in which the glutamatergic neurotransmitter system is perturbed. However, the action of Yokukansan in synaptic neurotransmission is unknown. In the present study, the action of Yokukansan in the glutamatergic neurotransmitter system was examined in zinc-deficient rats, a neurological disease model, in which the glutamatergic neurotransmitter system is perturbed. Administration of Yokukansan significantly suppressed the increase in extracellular concentrations of glutamate and aspartate in the hippocampus after stimulation with 100 mM KCl, but not the increase in extracellular concentrations of glycine and taurine, suggesting that Yokukansan is involved in modulation of excitatory neurotransmitter systems. The present study demonstrates that Yokukansan is a possible medicine for prevention or cure of neurological diseases associated with excitotoxicity.

Association of serum cytokine concentrations with psychological symptoms in midlife women.

OBJECTIVE: The purpose of the present study was to clarify the association of serum cytokine concentrations, determined using a multiplexed cytokine assay, with psychological symptoms in midlife women. METHODS: Fifty-three peri- and post-menopausal women with and without psychological symptoms in Greene's climacteric scale were enrolled in this study. Levels of 17 cytokines in serum samples were measured simultaneously using a multiplexed human cytokine assay. RESULTS: Serum interleukin (IL)-6 concentration in women with psychological symptoms (2.71+/-047 pg/ml) was significantly (p=0.009) higher than that in women without psychological symptoms (0.98+/-0.18 pg/ml). Serum IL-8 concentration in women with psychological symptoms (33.4+/-8.17 pg/ml) was also significantly (p=0.022) higher than that in women without psychological symptoms (7.87+/-1.64 pg/ml). In addition, serum IL-10 concentration in women with psychological symptoms (0.74+/-0.26 pg/ml) was significantly (p=0.048) higher than that in women without psychological symptoms (0.07+/-0.04 pg/ml). Tumor necrosis factor (TNF)-alpha in serum was detected only in women with psychological symptoms. Serum IL-2 concentration in women with psychological symptoms tended (p=0.066) to be higher than that in women without psychological symptoms. No significant differences were found between levels of other cytokines in women with and without psychological symptoms. CONCLUSION: Psychological stress manifested as climacteric symptoms in midlife women may be associated with increases in serum concentrations of IL-6, IL-8, IL-10, and TNF-alpha.

Changes in serum cytokine concentrations during the menopausal transition.

OBJECTIVE: The purpose of the present study was to clarify the changes in serum concentrations of 17 cytokines in healthy women during the menopausal transition by using a multiplexed cytokine assay and to clarify the associations of these cytokines with serum estradiol concentration. METHODS: Sixteen premenopausal, 54 perimenopausal and 52 postmenopausal women were enrolled in this study. Seventeen cytokines in serum samples were measured simultaneously using a Bio-Plex human cytokine 17-Plex assay. RESULTS: Serum IL-6 concentration showed a weak positive correlation with age (r=0.196, p<0.05). Postmenopausal women for whom less than 5 years had passed since menopause showed significant (p<0.05) increase in serum concentrations of IL-2, GM-CSF and G-CSF, while serum IL-4 concentration was significantly (p<0.05) increased in postmenopausal women for whom more than 5 years had passed since menopause. Serum estradiol concentration showed a significant negative correlation with serum IL-6 concentration and weak negative correlations with serum concentrations of IL-2, IL-8 and GM-CSF. CONCLUSION: We were able to simultaneously measure the levels of 17 cytokines using a highly sensitive cytokine assay, and we found that the changes in serum cytokine concentrations during the menopausal transition differed. We also found that serum IL-6 concentration during the menopausal transition was negatively correlated with serum estradiol concentration.

Association of interleukin-8 with hot flashes in premenopausal, perimenopausal, and postmenopausal women and bilateral oophorectomized women.

OBJECTIVE: The purpose of this study was to identify serum cytokine concentrations in premenopausal, perimenopausal, and postmenopausal women and bilateral oophorectomized women with hot flashes. METHODS: Serum concentrations of 17 cytokines were simultaneously measured using a multiplexed human cytokine assay in 129 premenopausal, perimenopausal, and postmenopausal women and 50 bilateral oophorectomized women. RESULTS: Serum IL-8 concentrations in midlife women and bilateral oophorectomized women with severe hot flashes were significantly higher than the concentrations in women without hot flashes and women with mild and moderate hot flashes. Serum macrophage inflammatory protein-1beta concentration in women with severe hot flashes was significantly higher than those in women without hot flashes and women with mild and moderate hot flashes. CONCLUSION: Serum IL-8 concentrations in premenopausal, perimenopausal, and postmenopausal women and bilateral oophorectomized women with hot flashes were significantly higher than those in women without hot flashes. IL-8 may be associated with peripheral vasodilation in women with hot flashes.

Antinociceptive effect of methyleugenol on formalin-induced hyperalgesia in mice.

The effects of methyleugenol, an essential oil isolated from Asiasari radix, on antinociception were examined using the formalin test in mice. Oral administration of 10 mg/kg methyleugenol significantly decreased the duration of licking and biting behavior in the second phase without affecting that of the first phase, as did diclofenac, a non-steroidal anti-inflammatory drug. Methyleugenol also inhibited pain-related behaviors induced by intrathecal injection of N-methyl-d-aspartic acid (NMDA), while diclofenac did not affect these behaviors. These effects of methyleugenol were suppressed by bicuculline, a gamma-aminobutyric acid(A) (GABA(A)) antagonist. Muscimol, a GABA(A) agonist, displays the same action as methyleugenol with respect to the formalin test and NMDA-induced behaviors. Methyleugenol did not affect cyclooxygenase-1 and -2 activities. These results suggest that the antinociceptive effect of methyleugenol on the second phase of formalin-induced pain may be due to the inhibition of NMDA receptor-mediated hyperalgesia via GABA(A) receptors.

Skin temperature rise induced by calcitonin gene-related peptide in gonadotropin-releasing hormone analogue-treated female rats and alleviation by Keishi-bukuryo-gan, a Japanese herbal medicine.

The effects of Keishi-bukuryo-gan on calcitonin gene-related peptide (CGRP)-induced elevation of skin temperature were investigated in gonadotropin-releasing hormone (GnRH) analogue-treated female rats. Leupline (1.0 mg/kg) as the GnRH analogue was subcutaneously (s.c.) injected into female rats. After Keishi-bukuryo-gan (100-1,000 mg/kg, p.o.) or 17beta-estradiol (0.010 mg/kg, s.c.) was administered to GnRH analogue-treated rats for 14 days, CGRP-induced skin temperature elevation, concentration of plasma 17beta-estradiol and pituitary gonadotropin (luteinizing hormone; LH, and follicle stimulating hormone; FSH) were measured. In addition, effects of 17beta-estradiol and Keishi-bukuryo-gan on the proliferation of estrogen-dependent human breast cancer (MCF-7) cells were investigated under in vitro conditions. GnRH analogue significantly lowered the concentrations of plasma 17beta-estradiol and pituitary gonadotropins. Tissue weights of the ovaries and uterus were also decreased by the analogue. Under the condition of estrogen deficiency, intravenous (i.v.) injection of exogenous CGRP (10 microg/kg) elevated the skin temperature of the hind paws more significantly than it did in sham-treated control rats. Estrogen supplementation inhibited this elevation of skin temperature with restoration of both the lowered plasma estrogen level and the decreased uterine weight in GnRH analogue-treated rats. On the other hand, Keishi-bukuryo-gan inhibited the elevation of skin temperature in a dose-dependent manner without restoring the plasma estrogen level and uterine weight. In addition, in an in vitro study, MCF-7 cells proliferated in a dose-dependent manner by the addition of 17beta-estradiol (10(-13)-10(-8) M) to the medium. However, Keishi-bukuryo-gan (10(-6)-10(-4) mg/ml) did not activate the MCF-7 cell proliferation. These results suggest that Keishi-bukuryo-gan, which does not exhibit estrogen activity, may be useful for the treatment of hot flashes in women who are undergoing medical ovariectomy with a GnRH analogue.

Keishibukuryogan, a Traditional Japanese Medicine, Inhibits Platelet Aggregation in Guinea Pig Whole Blood.

Effects of keishibukuryogan (KBG) on platelet aggregation were investigated. To ensure the specificity of KBG, tokishakuyakusan (TSS) and kamisyoyosan (KSS), which are known to have platelet aggregation-inhibiting effects, and rikkunshito (RKT) and shakuyakukanzoto (SKT), which are considered to be devoid of such effects, were used for comparison. The platelet aggregation of each test drug was measured by the screen filtration pressure method using whole blood of guinea pigs and expressed as a collagen-induced pressure rate (%) or a collagen concentration required for 50% increase in the pressure rate (PATI value). KBG suppressed the collagen-induced whole blood pressure rate increase and increased the PATI value, like TSS and KSS. Neither RKT nor SKT showed these effects. The Moutan cortex and Cinnamomi cortex, the constituent crude drugs of KBG, showed KBG-like pressure rate suppression and PATI-increasing effects. Furthermore, paeonol, a representative component of Moutan cortex, and aspirin which is known to have platelet aggregation-inhibiting activity (COX-1 inhibitor) also showed similar effects. These results suggest that the platelet aggregation-inhibiting activity of the constituent crude drugs Moutan cortex and Cinnamomi cortex is involved in the improving effects of KBG on impaired microcirculation and that paeonol plays a role in these effects.

Geissoschizine methyl ether, an indole alkaloid extracted from Uncariae Ramulus et Uncus, is a potent vasorelaxant of isolated rat aorta.

Effects of geissoschizine methyl ether, an indole alkaloid isolated from the hook of Uncariae Ramulus et Uncus, on vascular responses were examined using isolated strips of rat aorta. Geissoschizine methyl ether (10(-7)-10(-4) M) relaxed norepinephrine (5x10(-8) M)-induced contraction in a dose-dependent manner. The potency (50% efficacy concentration, EC(50)=0.744 microM) was approximately 14 times greater than that (EC(50)=10.6 microM) of hirsutine, one of the indole alkaloids isolated from Uncariae Ramulus et Uncus that demonstrates a vasorelaxant effect by Ca(2+)-channel blocking. The vasorelaxant effect of geissoschizine methyl ether found at the lower concentrations (10(-7)-3x10(-6) M) on the norepinephrine-induced contraction was abolished by pretreatment with N(G)-nitro-L-arginine (10(-4) M), an inhibitor of nitric oxide synthesis, or by denuding aortas of endothelium, while the effects at the higher concentrations (10(-5)-10(-4) M) were not completely prevented by either N(G)-nitro-L-arginine and deendothelialization. Furthermore, geissoschizine methyl ether did not relax high K(+)-, Ca(2+)- and a Ca(2+)-channel agonist Bay K8644-induced contractions at the lower concentrations that markedly relaxed the norepinephrine-induced contractions, while the higher concentrations of geissoschizine methyl ether relaxed the high K(+)-, Ca(2+)- and Bay K8644-induced contractions. These results suggest that the vasorelaxant effect of geissoschizine methyl ether is composed of two different mechanisms: endothelial dependency with nitric oxide and endothelial independency with voltage-dependent Ca(2+)-channel blocking.

Saiko-ka-ryukotsu-borei-to, an herbal medicine, prevents chronic stress-induced disruption of glucocorticoid negative feedback in rats.

Exposure to stress is known to precipitate or exacerbate many neuropsychiatric disorders such as depression. Abnormality of the neuroendocrine system, as shown by increased adrenal weight and attenuated glucocorticoid negative feedback, is frequently seen in depression. The aim of the present study is to clarify the usefulness of saiko-ka-ryukotsu-borei-to, an herbal medicine, in the treatment of abnormality of the neuroendocrine system using an experimental stress-depression model. Rats were subjected to water immersion and restraint for 2 h daily for 4 weeks (chronic stress), followed by recovery for 10 days. Saiko-ka-ryukotsu-borei-to was administered during the stress and recovery periods (100, 300, or 1000 mg/kg daily, p.o.) or only during the recovery period (1000 mg/kg). After the recovery period, the adrenal weight was measured, and glucocorticoid feedback ability was evaluated by a dexamethasone suppression test using 30 microg/kg dexamethasone. The administration of saiko-ka-ryukotsu-borei-to during the stress and recovery periods prevented the stress-induced increase in adrenal weight or the attenuated negative feedback in a dose-dependent manner. The administration of saiko-ka-ryukotsu-borei-to during the recovery period alone also ameliorated the abnormality of the neuroendocrine system. These results indicate that saiko-ka-ryukotsu-borei-to is effective against chronic stress-induced abnormality of the neuroendocrine system. Because some symptoms and symptomatic relapses in depressives are attributed to dysfunction of the hypothalamo-pituitary-adrenal axis, the present findings provide information important for prevention and treatment of depression.

Experimental anxiety induced by histaminergics in mast cell-deficient and congenitally normal mice.

To clarify the effect of mast cell-derived histamine release in the brain on anxiety, histaminergics-induced anxiety-like behaviors were examined by a light/dark test in mast cell-deficient (W/Wv) and congenitally normal (+/+) mice. In +/+ mice, when cimetidine (an H2 receptor antagonist) was coadministered with thioperamide (a neuronal histamine releaser acting via inhibition of H3 autoreceptors) or Compound 48/80 (C48/80, a selective histamine releaser from mast cells), the time spent in the light zone and the number of crossings between light and dark zones in a light/dark test decreased significantly, suggesting induction of anxiety. In W/Wv mice, however, experimental anxiety was induced by coadministration of thioperamide-cimetidine, but not C48/80-cimetidine. These results suggest that both nonneuronal mast cell-derived histamine and neuronal histamine play an important role in inducing experimental anxiety.

Saiko-ka-ryukotsu-borei-to, a herbal medicine, ameliorates chronic stress-induced depressive state in rotarod performance.

Exposure to chronic stress is thought to play an important role in the etiology of depression. This disorder has been shown to involve disruption of the hypothalamo-pituitary-adrenal (HPA) system and dysfunction of the prefrontal cortex (PFC). We have demonstrated that chronic stress in rats induces similar HPA disruption or a depressive state caused by a reduction of dopaminergic and serotonergic transmission in the PFC. We have also shown that saiko-ka-ryukotsu-borei-to, a herbal medicine, prevents such chronic stress-induced HPA disruption. However, the behavioral and neurochemical bases of this drug remain unclear. Here we examined the effects of saiko-ka-ryukotsu-borei-to on the depressive behavioral state and the reduction of transmission resulting from chronic stress. The chronic stress was induced by water immersion and restraint (2 h/day) for 4 weeks followed by recovery for 10 days. The treatment with saiko-ka-ryukotsu-borei-to (100, 300, or 1000 mg/kg p.o.) ameliorated the stress-induced depressive state in a dose-dependent manner, evaluated by a rotarod test. A microdialysis study indicated that the drug treatment significantly prevented the chronic stress-induced decreases in extracellular concentrations of dopamine and serotonin in the PFC. These results suggest that saiko-ka-ryukotsu-borei-to ameliorates the chronic stress-induced depressive state based on the prevention of PFC dysfunction. These findings provide important information for treatment of depression.