Masamichi Noguchi

Urocortin 1 reduces food intake and ghrelin secretion via CRF2 receptors

Although it is known that urocortin 1 (UCN) acts on both corticotropin-releasing factor receptors (CRF(1) and CRF(2)), the mechanisms underlying UCN-induced anorexia remain unclear. In contrast, ghrelin, the endogenous ligand for the growth hormone secretagogue receptor, stimulates food intake. In the present study, we examined the effects of CRF(1) and CRF(2) receptor antagonists (CRF(1)a and CRF(2)a) on ghrelin secretion and synthesis, c-fos mRNA expression in the caudal brain stem, and food intake following intracerebroventricular administration of UCN. Eight-week-old, male Sprague-Dawley rats were used after 24-h food deprivation. Acylated and des-acylated ghrelin levels were measured by enzyme-linked immunosorbent assay. The mRNA expressions of preproghrelin and c-fos were measured by real-time RT-PCR. The present study provided the following important insights into the mechanisms underlying the anorectic effects of UCN: 1) UCN increased acylated and des-acylated ghrelin levels in the gastric body and decreased their levels in the plasma; 2) UCN decreased preproghrelin mRNA levels in the gastric body; 3) UCN-induced reduction of plasma ghrelin and food intake were restored by CRF(2)a but not CRF(1)a; 4) UCN-induced increase of c-fos mRNA levels in the caudal brain stem containing the nucleus of the solitary tract (NTS) was inhibited by CRF(2)a; and 5) UCN-induced reduction of food intake was restored by exogenous ghrelin and rikkunshito, an endogenous ghrelin secretion regulator. Thus, UCN increases neuronal activation in the caudal brain stem containing NTS via CRF(2) receptors, which may be related to UCN-induced inhibition of both ghrelin secretion and food intake.

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 Greenes climacteric scale. Serum levels of cytokines were measured using a multiplexed human cytokine assay. RESULTS Greenes total scores in both women treated with paroxetine and in women treated with kamishoyosan decreased significantly. Percentage decreases in Greenes 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 Japanese traditional medicines on circulating cytokine levels in women with hot flashes.

Objective:The effects of the Japanese traditional medicines keishibukuryogan and kamishoyosan on circulating cytokines were examined to clarify the difference in the actions of Japanese traditional medicines in women with hot flashes. Methods:Seven premenopausal, 51 perimenopausal, 45 spontaneously postmenopausal and 17 surgically postmenopausal women who had complained of hot flashes were enrolled in this study. Eighty women who hoped to receive Japanese traditional medicines were randomly assigned in open, parallel-group fashion to a keishibukuryogan group or kamishoyosan group. Forty women who did not want any treatment for hot flashes were followed up for 6 months as a control group. Serum levels of cytokines were measured using a multiplexed human cytokine assay. Results:The proportions of responders in women treated with keishibukuryogan and kamishoyosan were 73.7% and 69.2%, respectively. Serum monocyte chemotactic protein-1 level in women treated with keishibukuryogan decreased significantly (P = 0.0037). On the other hand, concentrations of interleukin (IL)-6 and macrophage inflammatory protein-1&bgr; in women treated with kamishoyosan decreased significantly (P = 0.019 and P = 0.039, respectively). In both keishibukuryogan and kamishoyosan responder groups, serum IL-8 concentrations were reduced significantly (P = 0.021 and P = 0.014, respectively). Conclusions:Both treatments with keishibukuryogan and kamishoyosan reduce the circulating IL-8 level, which is involved in thermoregulation in perimenopausal women with hot flashes. In addition, keishibukuryogan decreases circulating monocyte chemotactic protein-1 level in postmenopausal women.

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-1β, interleukin-8 and macrophage inflammatory protein-1β 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.

Raloxifene reduces circulating levels of interleukin-7 and monocyte chemoattractant protein-1 in postmenopausal women

OBJECTIVE The aim of the present study was to determine the effects of raloxifene on changes in circulating levels of cytokines and chemokines in relation to changes in lipid profiles and markers of inflammation in postmenopausal women. METHODS Fifty-three postmenopausal women aged 45-65 years old were randomly assigned in open, parallel-group fashion to a control group or raloxifene group. Twenty-six women received oral administration of 60 mg raloxifene every day and 27 women did not receive any drugs for 12 months. Serum cytokines levels were simultaneously measured using a multiplexed human cytokine assay. RESULTS Serum IL-7 concentrations in women who received raloxifene were decreased significantly (p=0.014), and serum monocyte chemoattractant protein (MCP)-1 concentrations in women who received raloxifene were decreased significantly (p=0.0003) at 12 months. In the control group, serum levels of MCP-1 and IL-7 did not show significant changes. There were significant differences (p=0.032 and p=0.0024, respectively) in percentage changes in IL-7 and MCP-1 in the control group and in the raloxifene group. Levels of low-density lipoprotein cholesterol (LDL-C) and E-selectin were decreased significantly in women who received raloxifene, but the percentage changes in LDL-C and E-selectin over a period of 12 months were not significantly correlated with percentage changes in IL-7 and MCP-1 over the same period. CONCLUSION Circulating levels of IL-7 and MCP-1 decrease in postmenopausal women who received raloxifene.

Involvement of calcitonin gene-related peptide in elevation of skin temperature in castrated male rats

OBJECTIVES To assess the involvement of calcitonin gene-related peptide (CGRP) in the occurrence of hot flashes in men after castration for treatment of prostate cancer, we investigated the effects of CGRP on skin temperature in surgically and medically castrated male rats. METHODS Changes in skin temperature of the hind paws after intravenous injection of 10 microg/kg of CGRP and CGRP family peptides (adrenomedullin and amylin) were measured at 5-minute intervals for 120 minutes, 3 weeks after bilateral orchiectomy or 2 weeks after subcutaneous injection of a gonadotropin-releasing hormone analogue (1.0 mg/kg Leuplin) in male rats. Antagonism with CGRP8-37 (1000 microg/kg intravenously), a CGRP1 receptor antagonist, to the CGRP-induced response was examined by injecting it 10 minutes before injection of CGRP. The effect of testosterone replacement on castration was evaluated in each castrated rat by the administration of testosterone (1.0 mg/kg subcutaneously once a day) for 14 days before the day of the temperature analysis. RESULTS CGRP, but not adrenomedullin and amylin, elevated the skin temperature in surgical or medical castration-induced testosterone-deficient rats more than in the sham-treated rats. The difference was statistically significant. The CGRP-induced potentiation in the castrated rats was inhibited by pretreating with CGRP8-37 or by supplying testosterone. CONCLUSIONS CGRP is the most potent peptide in a family that elevates the skin temperature in male rats. The elevation of the skin temperature was more affected by the testosterone deficiency resulting from castration. These results suggest that CGRP is involved in the mechanism underlying hot flashes in men.

Significance of measured elevation of skin temperature induced by calcitonin gene-related peptide in anaesthetized rats.

To assess whether peripheral changes related to skin temperature rise were induced by ovarian hormone deficiency, we investigated the effects of anaesthesia on calcitonin gene‐related peptide (CGRP)‐ or luteinizing hormone‐releasing hormone (LH‐RH)‐induced elevation of skin temperature in female rats. CGRP was used as an inducer of peripherally‐mediated elevation of skin temperature, whereas LH‐RH was used as an inducer of centrally‐mediated elevation of skin temperature. Intravenous (i.v.) but not intracerebroventricular injection of CGRP (10 μg kg−1) or intracerebroventricular but not intravenous injection of LH‐RH (10 μg/rat) elevated the skin temperature of unanaesthetized rats restrained in a Ballmans cage. The elevation with LH‐RH was completely inhibited by urethane anaesthesia, whereas the elevation with CGRP was not. These results suggested that changes in skin temperature measured under anaesthesia reflected a peripherally rather than a centrally mediated mechanism. The CGRP (1.0–30 μg kg−1, i.v.)‐induced elevation of skin temperature was potentiated in ovariectomized rats and inhibited by pretreatment with a CGRP receptor antagonist CGRP8–37 (1000 μg kg−1, i.v.), suggesting that the potentiation may participate in peripheral factors such as a postsynaptic hypersensitivity to CGRP following ovarian hormone deficiency. Thus, measurement of skin temperature in the anaesthetized rat was a useful procedure to seek the peripheral mechanism of potentiation of skin temperature induced by CGRP, thought to be closely related to menopausal hot flashes.

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.

Urocortin1-induced anorexia is regulated by activation of the serotonin 2C receptor in the brain.

This study was conducted to determine the mechanisms by which serotonin (5-hydroxytryptamine, 5-HT) receptors are involved in the suppression of food intake in a rat stress model and to observe the degree of activation in the areas of the brain involved in feeding. In the stress model, male Sprague-Dawley rats (8 weeks old) were given intracerebroventricular injections of urocortin (UCN) 1. To determine the role of the 5-HT2c receptor (5-HT2cR) in the decreased food intake in UCN1-treated rats, specific 5-HT2cR or 5-HT2b receptor (5-HT2bR) antagonists were administered. Food intake was markedly reduced in UCN1-injected rats compared with phosphate buffered saline treated control rats. Intraperitoneal administration of a 5-HT2cR antagonist, but not a 5-HT2bR antagonist, significantly inhibited the decreased food intake. To assess the involvement of neural activation, we tracked the expression of c-fos mRNA as a neuronal activation marker. Expression of the c-fos mRNA in the arcuate nucleus, ventromedial hypothalamic nucleus (VMH) and rostral ventrolateral medulla (RVLM) in UNC1-injected rats showed significantly higher expression than in the PBS-injected rats. Increased c-fos mRNA was also observed in the paraventricular nucleus (PVN), the nucleus of the solitary tract (NTS), and the amygdala (AMG) after injection of UCN1. Increased 5-HT2cR protein expression was also observed in several areas. However, increased coexpression of 5-HT2cR and c-fos was observed in the PVN, VMH, NTS, RVLM and AMG. Whereas, pro-opiomelanocortin mRNA expression was not changed. In an UNC1-induced stress model, 5-HT2cR expression and activation was found in brain areas involved in feeding control.