Intestinal flora induces the expression of Cyp3a in the mouse liver.

In order to determine the effects of intestinal flora on the expression of cytochrome P450 (CYP), the mRNA expression of CYP was compared between specific pathogen-free (SPF) and germ-free (GF) mice. Most of the major CYP isozymes showed higher expression in the livers of SPF mice compared with GF mice. Nuclear factors such as pregnane X receptor (PXR) and constitutive androstane receptor (CAR), as well as transporters and conjugation enzymes involved in the detoxification of lithocholic acid (LCA), also showed higher expression in SPF mice. The findings suggest that in the livers of SPF mice, LCA produced by intestinal flora increases the expression of CYPs via activation of PXR and CAR. Drugs such as antibiotics, some diseases and ageing, etc. are known to alter intestinal flora. The present findings suggest that such changes also affect CYP and are one of the factors responsible for individual differences in pharmacokinetics.

Stress on a postpartum mother inhibits the secretion of growth hormone in the offspring and causes persistent growth impairment.

Children exposed to environmental stress in the early neonatal period often develop psychiatric or somatic diseases in adulthood. In the present study in mice, we examined how postpartum stress on the mother influences their pups and thus tried to provide new insight into the management of idiopathic short stature. The dams were exposed to daily 3-h immobilization stress (IS) only for 3 weeks from the day after delivery. When compared to the pups of nonstressed dams (control pups), those of the IS dams (IS pups) showed lower body weight and height, which persisted even into adulthood. Their nutritional status was normal. The IS pups also showed low serum concentrations of insulin-like growth factor I (IGF-I) and poor responses to growth hormone-releasing hormone (GHRH) stimulation on day 22 and were behaviorally hyperactive at 8 weeks. Immunohistochemical analysis demonstrated that the number of pituitary GH-positive cells in response to treatment with GHRH was markedly decreased in the IS pups compared to the control pups. The IS dams did not show apparent behavioral abnormalities except downregulation of glucocorticoid receptor (GR) gene expression in the hippocampus. These results suggest that the perturbation of GH secretion in the pituitary glands is involved in the lifelong growth impairment of the IS pups.

[Angina pectoris in patients who underwent stent implantations for severe atherosclerotic coronary lesions 16 years after heart transplantation].

The case was a 56-year-old male who underwent heart transplantation due to dilated cardiomyopathy abroad in 1990. In 2006, he suffered from anginal chest pain on effort. The coronary angiogram showed severe atherosclerotic lesions in the middle of left descending artery. A drug eluting stent, Cypher 3.5 x 23 mm was deployed, followed by balloon dilatations (4 x 8 mm). The procedure was successful without any complications. Furthermore, the 8-month follow-up angiogram showed no significant restenosis in the target vessel. There have been several reports on the outcomes of percutaneous coronary intervention (PCI) for cardiac allograft vasculopathy. According to them, the drug eluting stent, as is used in the present case, might be a promising procedure after further evaluations.

Chronic stress attenuates glucocorticoid negative feedback: involvement of the prefrontal cortex and hippocampus.

Disruption of the glucocorticoid negative feedback system is observed in approximate one half of human depressives, and a similar condition is induced in animals by chronic stress. This disruption is thought to involve down-regulation of glucocorticoid receptors (GRs) in the feedback sites of the brain. However, the responsible site of the brain has not been well elucidated. Here we examined the effects of chronic stress induced by water immersion and restraint (2 h/day) for 4 weeks followed by recovery for 10 days on the GR levels in the prefrontal cortex (PFC), hippocampus, and hypothalamus of rats using a Western immunoblot technique. In the PFC, the cytosolic GR levels were decreased, but the nuclear GR levels were not changed. In the hippocampus, the levels of cytosolic and nuclear GRs were increased. However, there were no marked changes in the GR levels in the hypothalamus. The changes in the cytosolic GR levels were confirmed at the mRNA level by an in situ hybridization technique. We next examined the suppressive effects of dexamethasone (DEX) infusions into these regions on the circulating corticosterone levels. When DEX was infused into the PFC or hippocampus of the chronically stressed rats, the suppressive response to DEX was abolished, but the response was normal in the hypothalamus. In addition, when DEX was injected systemically to the chronically stressed rats, the suppressive response to DEX was significantly attenuated. These results suggest that the abnormal changes in GRs in the higher centers of the hypothalamo-pituitary-adrenal axis are involved in the chronic stress-induced attenuation of the feedback. Since dysfunction of the PFC or hippocampus is implicated in the pathogenesis of depression, the present findings would help to understand the mechanisms underlying the disrupted feedback system and its relation to brain dysfunction in depression.

Suppressive effect of the herbal medicine Oren-gedoku-to on cyclooxygenase-2 activity and azoxymethane-induced aberrant crypt foci development in rats.

The present study is part of a program to obtain effective chemopreventive agents with low toxicity from medicinal herbs and traditional herbal medicines. We previously reported that Oren (Coptidis rhizoma) and Ogon (Scutellariae radix) inhibit azoxymethane (AOM)-induced aberrant crypt foci (ACF) formation. In the present investigation, we found Sanshishi (Gardeniae fructus) and the traditional herbal medicine Oren-gedoku-to (OGT), composed of Ogon, Oren, Sanshishi and Obaku, also have preventive potential. Sanshishi and OGT decreased the numbers of ACF to 25.2 and 59.4% of the control value at 2% in the diet, respectively. Adverse effects, evidenced by body weight loss, were weaker with OGT than component herbs. To investigate their mechanisms of action, the influence on cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) activities was studied. Both OGT and Sanshishi inhibited COX-2 but not COX-1, this presumably contributing to their suppressive effects on ACF development. The results suggest that OGT may be useful for colon cancer chemoprevention in terms of efficacy and toxicity.

Up-regulation of calcitonin gene-related peptide receptors underlying elevation of skin temperature in ovariectomized rats.

We investigated the mechanism for the augmentation of the calcitonin gene-related peptide (CGRP)-induced elevation of skin temperature in ovariectomized (OVX) rats. I.v. injection of alphaCGRP (10 micro g/kg) elevated skin temperature of the hind paws. The elevation was significantly greater in OVX rats than in sham-operated rats and was inhibited by pretreatment with human CGRP(8-37) (100-1000 micro g/kg i.v.), a CGRP receptor antagonist, in a dose-dependent manner. In addition, ovariectomy not only potentiated vasorelaxation due to alphaCGRP but increased the number of CGRP receptors in mesenteric arteries. Further, the plasma concentration of endogenous CGRP was significantly lower in OVX rats. These results suggest that the low concentration of plasma CGRP due to ovarian hormone deficiency may induce the increase in the number of CGRP receptors due to up-regulation. Therefore, the increased number of CGRP receptors may be responsible for potentiation of exogenous alphaCGRP-induced elevation of skin temperature in OVX rats. The mechanism underlying the hot flashes observed in menopausal women may also involve, in part, the up-regulation of CGRP receptors following ovarian hormone deficiency.

Effects of the Japanese herbal medicine Keishi-bukuryo-gan and 17beta-estradiol on calcitonin gene-related peptide-induced elevation of skin temperature in ovariectomized rats.

The effects of a Japanese herbal medicine, Keishi-bukuryo-gan, and 17beta-estradiol on calcitonin gene-related peptide (CGRP)-induced elevation of skin temperature were investigated in ovariectomized (OVX) rats. Ovariectomy not only potentiated CGRP-induced elevation of skin temperature and arterial vasorelaxation but also induced a lower concentration of endogenous CGRP in plasma and up-regulation of arterial CGRP receptors, suggesting that lowered CGRP in plasma due to ovarian hormone deficiency increases the number of CGRP receptors and consequently amplifies the stimulatory effects of CGRP to elevate skin temperature. Oral Keishi-bukuryo-gan (100-1000 mg/kg, once a day for 7 days) restored a series of CGRP-related responses observed in OVX rats by normalizing plasma CGRP levels in a dose-dependent manner as effectively as s.c. injection. 17Beta-estradiol (0.010 mg/kg, once a day for 7 days). However, Keishi-bukuryo-gan did not affect the lower concentration of plasma estradiol and the decreased uterine weight due to ovariectomy, although the hormone replacement of 17beta-estradiol restored them. These results suggest that Keishi-bukuryo-gan, which does not confer estrogen activity on plasma, may be useful for the treatment of hot flashes in patients for whom estrogen replacement therapy is contraindicated, as well as menopausal women.

Chronic stress differentially regulates glucocorticoid negative feedback response in rats.

Exposure to chronic stress is thought to play an important role in the etiology of depression. In this disorder, a disrupted negative feedback response to exogenous glucocorticoids on cortisol secretion has been indicated. However, the regulation of glucocorticoid negative feedback by chronic stress is not fully understood. In the present study, we investigated the effects of chronic stress administered by water immersion and restraint (2 h/day) for four weeks on the glucocorticoid feedback in rats. In the acutely (one-time) stressed rats, the basal plasma corticosterone (CORT) level was markedly elevated, remained at high levels for 5 h after the termination of stress, and then decreased. In the chronically stressed rats, the CORT level was initially elevated similarly, but rapidly decreased at 2 h. In the dexamethasone (DEX) suppression test, the peak CORT level in response to stress was not suppressed by DEX in the acutely stressed rats, but was significantly suppressed in the chronically stressed rats. In contrast, the suppressive effects of DEX on the basal CORT secretion in naive rats were attenuated in the chronically stressed rats. In the chronically stressed hippocampus, which plays an important role in the regulation of the glucocorticoid feedback response, the binding of [3H]DEX was decreased and the increased response of activator protein-1 induced by acute stress was abolished. These results suggest that chronic stress induces a hypersuppressive state for induced CORT secretion in response to acute stress, which is caused by partial habituation, coping, and adaptation to the stressor, whereas it induces a hyposuppressive state for the basal CORT secretion, which is caused by glucocorticoid receptor downregulation. These mechanisms may be involved in the stress-induced neural abnormalities observed in depression.

Effect of chronic stress on cholinergic transmission in rat hippocampus.

We previously demonstrated that chronic stress impaired prefrontal cortex-sensitive working memory, but not reference memory. Since the hippocampal cholinergic system is also involved in these memories, we examined the effects of chronic stress on cholinergic transmission in the rat hippocampus. A microdialysis study revealed that the stress did not affect the basal acetylcholine release, but enhanced the KCl-evoked response. These results suggest that cholinergic transmission in the chronically stressed hippocampus does not contribute to working memory impairment, but it may be involved in maintenance of reference memory.

Damage of hippocampal neurons caused by cobalt focus in the cerebral cortex of rats.

The relationship between the focus of cobalt seizures in the cerebral cortex and neuron loss in the hippocampus, as well as the CD50 of pentylenetetrazol was examined in rats. Spike activity in EEG frequently appeared 4 days after cobalt application and reached a peak 8-16 days after cobalt application, which was sometimes accompanied by jerks in the limbs. Changes in the CD50 value showed a two-step pattern, i.e., the first decrease in CD50 appeared one day after application of cobalt and continued at the same value until the fourth day. Then a second gradual decrease of CD50 was observed from the fourth day to eighth day and continued at the same value until 20 days after cobalt application. Neuron loss in the CA1 area of the hippocampus was observed as early as two days after cobalt application and the degree of neuron loss progressively increased until the 20th day. These findings suggest that neuron loss in the hippocampus following cobalt-induced seizures is not a result of generalized convulsions.

An inhibitory effect of cytokine-induced neutrophil chemoattractant on corticotropin-releasing factor-induced increase in locomotor activity.

To investigate whether cytokine-induced neutrophil chemoattractant (CINC) has an influence on corticotropin-releasing factor (CRF) in the central nervous system, the effects of intracerebroventricular (i.c.v.) injection of CINC on CRF-induced behavior were examined. Intracerebroventricular CRF injection produced an increase in locomotor activity, which was significantly reduced by i.c.v. injection of CINC. The intravenous injection of CINC did not alter CRF-induced locomotor hyperactivity. These results suggested that CINC has a functional antagonistic action on the response to CRF and may attenuate stress responses.

Release of zinc from the brain of El (epilepsy) mice during seizure induction.

Brain distribution after i.v. injection of 65ZnCl2 into El mice, an animal model of genetically determined epilepsy, was studied by autoradiography to study the utilization of zinc in the brain. The distribution of 65Zn in the brain of El mice 6 days after injection was almost the same as that of ddY (normal) mice, suggesting that the uptake of zinc by the brain of El mice is normal. To study the movement of zinc in the brain in the course of seizure induction, the concentrations of 65Zn in the brain of seizure-afflicted and untreated control El mice were compared 20 days after 65Zn injection. The concentration of 65Zn in the brain of seized El mice was overall lower than that of control El mice; the concentration of 65Zn was decreased notably in the piriform cortex and amygdaloid nuclei complex during convulsion. These results suggest that the release of zinc from the El mouse brain is enhanced during convulsion. The decrease in actively functioning zinc in the brain may be associated with the increase in susceptibility to seizure in the El mouse.

Characteristics of primary cultured neurons from embryonic mutant El mouse cerebral cortex.

To elucidate the differences between neurons of epileptogenic animals and those of normal animals, cellular characteristics of neurons of mutant strain El mice which are highly susceptible to seizures were investigated using immunocytochemical techniques. In neurons of 3-day primary cultures, the control ddY mouse neurons showed dividing stages in about 0.2% of neurofilament (NF)-positive neurons, whereas no dividing neurons were observed among the NF-positive El mouse neurons. In 7-day cultures, localization of GD3 ganglioside in the proliferating control ddY mouse neurons was observed, but there was no GD3 ganglioside in the mutant El mouse neuron. The content of GD3 ganglioside detected by high-performance thin-layer chromatography of El mouse cultured cells was ca. 1/4 of that of ddy mice. These findings suggest that neurons of the El mouse are differentiated earlier than those of the control ddY mouse.

Effects of cycloheximide on delayed neuronal death in rat hippocampus.

The effect of cycloheximide, a protein synthesis inhibitor, on hippocampal selective neuronal death was morphologically studied in rats subjected to 10 min forebrain ischemia using a 4-vessel occlusion model. Neuronal damage in the hippocampal CA1 subfield 72 h after ischemic insult was dramatically decreased by the lasting inhibition of protein synthesis through consecutive administration of cycloheximide. Cycloheximide, which was administered once within the first 24 h of recirculation, showed protective action on ischemic cell necrosis and its most potent effect was observed when injected at 12 h of post-ischemia. After 36 h of recirculation, however, treatment with cycloheximide could no longer prevent cell death. The possibility is considered that hippocampal delayed neuronal death following transient ischemia is caused by abnormal protein(s).

Inhibitory effect of TJ-960 (SK) on pentylenetetrazol-induced EEG power spectrum changes.

Effects of the Japanese kampo medicine 'Shosaiko-to-go-keishika-shyakuyaku-to' (TJ-960), which is a mixture of 9 herbal drugs and is practically equivalent to 'Saiko-keishi-to' (SK), on the pentylenetetrazol (PTZ)-induced EEG power spectrum changes were examined. The EEG power spectrum change with 2 PTZ administrations at an 80 min interval was clearly inhibited by oral administration of 1.0 mg/kg of TJ-960. By separate single administrations of the main component herbal drugs, Bupleuri radix, Cinnamomi cortex, Paeoniae radix and Zingiberis rhizoma, only Paeoniae radix showed statistically significant inhibition of PTZ-induced EEG power spectrum changes at a proportional dose of 1.0 mg/kg of TJ-960. The other main component herbal drugs showed no statistically significant inhibitory effect although they had a tendency to inhibit. These findings suggest that the Japanese Kampo medicine, TJ-960 (SK), has an inhibitory effect on PTZ-induced power spectrum changes and one of the component herbal drugs, Paeoniae radix, is the important component drug.

Inhibitory effect of a mixture of herbal drugs (TJ-960, SK) on pentylenetetrazol-induced convulsions in E1 mice.

TJ-960 is a spray-dried mixture of 9 herbal drugs. The convulsions of E1 mice induced by pentylenetetrazol (18 mg/kg) were completely inhibited by p.o. administration of TJ-960 at a daily dose of 1.0 g/kg both in 8-week-old and 4-week-old E1 mice. These findings suggest that TJ-960 has an inhibitory effect on the convulsions of this hereditary animal model of epilepsy.

Effect of anticonvulsants on pentylenetetrazol-induced power spectrum changes in electroencephalograms in rats.

The effect of anticonvulsants on pentylenetetrazol (PTZ)-induced EEG power spectrum changes was examined. When the minimum dose of PTZ (15 mg/kg) was administered intravenously twice, with an interval of 80 min, a clear EEG power spectrum change was observed after the second PTZ administration, irrespective of whether or not the first PTZ administration evoked marked EEG changes. We defined the values F/N, S/N and S/F. The value F/N, obtained by dividing the power spectrum area after the first PTZ administration by the normal power spectrum area, was 1.06 +/- 0.05 (mean +/- S.E.). The value S/N, obtained by dividing the power spectrum area after the second PTZ administration by the normal power spectrum area, was 2.00 +/- 0.21. The value S/F, obtained by dividing S/N by F/N, was 1.86 +/- 0.16. The S/F value was almost constant regardless of whether or not the first PTZ administration could evoke marked EEG changes. The effect of anticonvulsants was examined by S/F value changes, and 100 mg/kg of PHT completely inhibited the double PTZ effect. Phenobarbital, ethosuximide and sodium valproate also inhibited the double PTZ effect. Using the S/F value of the EEG power spectrum with minimum dose double PTZ administration, quantitative evaluation is possible for anticonvulsant drugs.

Pharmacological studies of the effect of Dai-kenchu-to on spontaneous contraction of isolated rabbit jejunum.

We studied the effects of Dai-kenchu to on the spontaneous contraction in isolated rabbit jejunum. Dai-kenchu-to (10(-3) g/ml) increased jejunal contraction, such as phasic like contraction and contractile amplitude. Zanthoxyli Fructus (2x10(-4) g/ml) exhibited an action identical to that of Dai-kenchu-to. While Zingiberis Siccatum Rhizoma (5x10(-4) g/ml) continuously decreased the amplitude of contraction. Ginseng Radix (3x10(-4) g/ml) and Saccharum Granorum (8x10(-3) g/ml) had no effect on spontaneous contraction. Dai kenchu-to and Zanthoxyli Fructus reversed the decrease of contraction produced by atropine. However, phasic like contraction induced in the absence of atropine was antagonized by atropine. Dai-kenchu-to and Zingiberis Siccatum Rhizoma further decreased spontaneous contraction in the presence of tetrodotoxin. It was clarified that Dai-kenchu-to possesses gastroprokinetic effect, and Zanthoxyli Fructus mainly contributed to this effect. It was suggested that the cholinergic and non cholinergic nervous systems were involved in increasing intestinal motility. It was also suggested that Dai-kenchu-to acted on multiple points of the intestine, and actions at these points might intensify to improve ileus.

Effects of Dai-kenchu-to on intestinal obstruction following laparotomy.

To confirm the usefulness of Dai-kenchu-to for intestinal obstruction, investigation of the effects of Dai-kenchu-to on postoperative intestinal adhesion was conducted. Repeated administrations of Dai-kenchu-to (100 or 300 mg/kg) significantly inhibited the formation of intestinal obstruction. Motor disturbance and inflammation are thought to be involved in the etiology of intestinal adhesion. A single treatment of Dai-kenchu-to (300 mg/kg) significantly reduce intestinal transit time in postoperative ileus and chemically induced ileus. Dai-kenchu-to (10(-4) g/ml) significantly inhibited COX-2 activity. These results suggest that Dai-kenchu-to prevents postoperative intestinal adhesion by gastroprokinetic and anti inflammatic effects. Dai-kenchu-to thus demonstrates positive effect on postoperative ileus.

The protective effect of hochu-ekki-to (TJ-41), a Japanese herbal medicine, against HSV-1 infection in mitomycin C-treated mice.

BACKGROUND: Immmunosuppression and infectious disease in cancer patients receiving chemotherapy is a serious problem. Immunopotentiating drugs may show a therapeutic efficacy. MATERIALS AND METHODS: The protective effect of Hochu-ekki-to (TJ-41), a Japanese traditional herbal medicine, on mitomycin C (MMC)-induced immunosuppression has been investigated. Spleen weight, the number of forming colonies of granulocytes and macrophages (CFU-GM) in the bone-marrow cells, natural killer (NK) activity in splenocytes and susceptibility to lethal herpes simplex virus type-1 (HSV-1) infection were evaluated. RESULTS: Oral administration of TJ-41 (2000 mg/kg/day) restored MMC-induced decline of spleen weight. CFU-GM and NK activity (20.6% to 68.4%, 48.8% to 77.7%, 21.1% to 95.1%, respectively). Moreover, MMC treatment resulted in a lethal HSV-1 infection and TJ-41 showed a preventive effect. CONCLUSION: TJ-41 may be beneficial for the treatment of infectious diseases in immunocompromised patients receiving chemotherapeutic drugs.