The herbal medicine Toki-shakuyaku-san improves the hypertension and intrauterine growth retardation in preeclampsia rats induced by Nomega-nitro-L-arginine methyl ester

The chronic inhibition of nitric oxide (NO) synthesis with Nomega-nitro-L-arginine methyl ester (L-NAME) induces a preeclampsia-like syndrome including hypertension and intrauterine growth retardation (IUGR) in pregnant rats. We tested the traditional herbal medicine Toki-shakuyaku-san (TS) for beneficial effects in this model. L-NAME was infused subcutaneously into pregnant rats from day 14 of gestation. TS (1 g/kg, 2 g/kg) was administered by gavage from day 14 to 20. Systolic blood pressure was measured on day 19. On day 20, rats were sacrificed and serum NO levels, placental weight, fetal body weight, fetal cerebrum weight and the thickness of the cerebral cortex were analyzed. TS (1 g/kg, 2 g/kg) inhibited L-NAME-induced hypertension. The decrease in fetal body weight, cerebrum weight and thickness of the cerebral cortex was abrogated by TS (2 g/kg). The effect of TS on blood pressure was found only in the rats that were both pregnant and infused with L-NAME. L-arginine, at the amount equivalent to that contained in TS, showed no effect. Further, the change in serum NO levels induced by TS was only marginal. TS thus improved the hypertension and IUGR in preeclampsia rats induced by L-NAME in a NO-independent manner. These data suggested that TS may be beneficial for the treatment and prevention of preeclampsia.

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.

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.

Preventive effects of Hange-shashin-to on irinotecan hydrochloride-caused diarrhea and its relevance to the colonic prostaglandin E2 and water absorption in the rat

The possible preventive effect of Kampo medicine Hange-shashin-to (TJ-14) on chronic diarrheal symptoms induced by the administration of the anticancer agent irinotecan hydrochloride (CPT-11) was investigated in the rat. Repeated oral administrations of TJ-14 at 125 and 500 mg/kg significantly prevented the reduction in body weight and the onset of chronic diarrheal symptoms due to CPT-11 in a dose-dependent manner, even though it failed to show a definite effect on acute diarrheal symptoms. In addition, treatment with TJ-14 accelerated the healing of the intestinal tract injured by repeated dosing of CPT-11 and inhibited significantly the increase of colonic prostaglandin E2 (PGE2) which is closely related to the onset of diarrhea. TJ-14 also improved colonic water absorption impaired by repeated dosing of CPT-11 in rats. These results demonstrate that TJ-14 is an effective medicine for the prevention and/or treatment of CPT-11-induced chronic diarrheal symptoms.

The effects of Hange-shashin-to on the content of prostaglandin E2 and water absorption in the large intestine of rats

The effects of Hange-shashin-to (TJ-14) were examined regarding the amount of prostaglandin E2 (PGE2) and the water absorbing capacity in the large intestine of rats. Repeated oral administration of TJ-14 at doses of 125 to 1000 mg/kg revealed a significant decrease in PGE2 content in the colonic mucosa and also the promotion of colonic water absorption in a dose dependent manner. However, there was no remarkable influence on the concentrations of aldosterone and electrolytes in the serum, even at 1000 mg/kg. From these results, it was considered that some of the anti-diarrheal effects of TJ-14 might be based on a repression of the increase in the amount of PGE2 as well as promotion of the water absorbing capacity of the large intestine. Moreover, it was also suggested that it is possible, by the application of TJ-14, to prevent the loss of water content caused by diarrhea.

Isolation and identification of hematopoietic stem cell-stimulating substances from Kampo (Japanese herbal) medicine, Juzen-taiho-to

We have previously found that TJ-48 has the capacity to accelerate recovery from hematopoietic injury induced by radiation and the anti-cancer drug mitomycin C (MMC). The effects are found to be due to its stimulation of spleen colony-forming unit (CFU-S) counts on day 14. In the present study, we attempt to isolate and purify the active components in TJ-48 extracts using a new in vitro hematopoietic stem cell (HSC) assay method. n-Hexane extract from TJ-48 shows a significant stimulatory activity. The extract is further fractionated by silica gel chromatography and HPLC in order to identify its active components. 1H-NMR and GC-EI-MS indicate that the active fraction is composed of free fatty acids (oleic acid and linolenic acid). When 27 kinds of free fatty acids (commercially available) are tested using the HSC proliferating assay, oleic acid, elaidic acid, and linolenic acid are found to have potent activity. The administration of oleic acid to MMC-treated mice enhances CFU-S counts on days 8 and 14 to twice the control group. These findings strongly suggest that fatty acids contained in TJ-48 actively promote the proliferation of HSCs. Although many mechanisms seem to be involved in the stimulation of HSC proliferation, we speculate that at least one of the signals is mediated by stromal cells, rather than any direct interaction with the HSCs.

Pharmacological studies on antidiarrheal effects of Hange-shashin-to

We attempted to characterize the antidiarrheal action of Hange-shashin-to (TJ-14), a kampo medicine, by comparing its action with that of loperamide. The oral administration of TJ-14 caused the dose-dependent suppression of castor oil-induced diarrhea at 250 to 1000 mg/kg. No significant repression was noted by TJ-14 even at 1000 mg/kg, p.o. for diarrhea induced by pilocarpine, serotonin or barium chloride. Oral treatment with loperamide at 5 mg/kg markedly suppressed diarrhea induced by castor oil and barium chloride. Contractions of isolated guinea pig ileum in response to acetylcholine (1 x 10(-7) g/ml), histamine (1 x 10(-7) g/ml) or barium chloride (3 x 10(-4) g/ml) were little affected by TJ-14 at 10(-4) g/ml. The responses elicited by the three contractive drugs were dose-dependently suppressed by loperamide. TJ-14 did not affect the small intestinal transit even at an oral dose of 1000 mg/kg. On the other hand, the small intestinal transit was significantly suppressed by loperamide (5 mg/kg, p.o.). These results indicate that TJ-14 can effectively control castor oil-induced diarrhea, and that its antidiarrheal action was not based on the suppression of intestinal motility.

Anti-hyperlipidemic and anti-atherosclerotic actions of shosaikoto (kampo medicine)

We investigated the anti-atherosclerotic action shown by Shosaikoto, a Kampo medicine, using hypercholesterolemic mice. Oral administration of Shosaikoto significantly suppressed the elevation of serum cholesterol in C57BL/6 mice fed a 1.25% cholesterol-enriched diet for four weeks and improved the T cell ratio in peripheral blood, which decreased with the increase of the serum cholesterol level. In addition, Shosaikoto reduced the accumulation of cholesteryl oleate, which alters macrophages into foam cells, after the treatment of macrophages with oxidized or acetylated low density lipoprotein (LDL). Enzymatic study revealed that the treatment of macrophages with oxidized LDL enhanced acyl-coenzyme A: cholesterol acyltransferase (ACAT) activity and markedly reduced neutral cholesteryl ester hydrolase (NCEase) activity. Shosaikoto treatment prevented a decrease in the NCEase activity, however due to the oxidized LDL treatment, although it slightly augmented ACAT activity. Thus, Shosaikoto, which is known to modulate the immune system, improves macrophage and lymphocyte functions diminished by hypercholesterolemia, resulting in an anti-atherosclerotic action.

Deoxycholic acid as an endogenous risk factor for hepatocarcinogenesis and effects of gomisin A, a lignan component of Schizandra fruits

Although hepatocarcinogensis has been reported to be promoted by exogenous administration of bile acids, the relation of endogenous bile acids to hepatocarcinogenesis is not completely understood. This study investigates the relationship between serum concentration of bile acids, the appearance of preneoplastic change, glutathione S-transferase placental form (GST-P)-positive foci in the liver of male Donryu rats which had been fed 0.06% 3'-methyl-4-dimethylamino-azobenzene (3'-MeDAB), and the effects of gomisin A, previously reported to inhibit the tumor promotion process. During the feeding of 3'-MeDAB for 5 weeks, the concentrations of serum bile acids were found to have increased significantly to several times the levels found at the start of the experiment. The increase of serum bile acids, especially deoxycholic acid (DCA), and the appearance of preneoplastic lesions, the number and area of GST-P-positive foci in the liver, were significantly inhibited by simultaneous oral administration of gomisin A (30 mg/kg). When DCA (100 mg/kg) was orally administered after an initiation by 3'-MeDAB, serum bile acids and preneoplastic changes were significantly increased, these increases were inhibited by combined feeding of 0.03% gomisin A in the diet. There were good correlations between the serum concentration of DCA and the number of GST-P-positive foci in the liver in both experimental protocols. These results confirm that DCA is an endogenous risk factor for hepatocarcinogenesis and suggest that anti-promoter effect of gomisin A is based on improving metabolism of bile acids, including DCA.

Inhibition of UDP-glucuronosyltransferase by aglycons of natural glucuronides in kampo medicines using SN-38 as a substrate

7-Ethyl-10-[4-(piperidino)-1-piperidino]carbonyloxycamptothecin (CPT-11), a potent anticancer agent for lung and gynecological cancers, is metabolized in vivo to the active compound, 7-ethyl-10-hydroxycamptothecin (SN-38), which is subsequently conjugated to SN-38-glucuronide by UDP-glucuronosyltransferase (UDP-GT). Three purified aglycons of natural glucuronides, baicalein, luteolin and glycyrrhetic acid, inhibited UDP-GT activity towards SN-38 as a substrate. The inhibitory potencies of these aglycons toward UDP-GT were similar to that of 1-naphthol. Based on these results, together with our previous finding that the corresponding glucuronides used in the present study strongly inhibited beta-glucuronidase in gut flora, we propose that materials in Kampo (Japanese herbal) medicines containing these aglycons of natural glucuronides could be used in vivo to decrease the enterohepatic circulation of SN-38 and other drugs.

Effects of gomisin A on the promotor action and serum bile acid concentration in hepatocarcinogenesis induced by 3'-methyl-4-dimethylamino-azobenzene

The effects of gomisin A, a lignan component of Schizandra fruits, on the promotion stage of hepatocarcinogenesis initiated by 3'-methyl-4-dimethylamino-azobenzene (3'-MeDAB) in male Donryu rats were investigated. When different types of tumor promotors, phenobarbital (PB) and deoxycholic acid (DCA), were administered for 5 weeks after initiation by 3'-MeDAB, preneoplastic alterations in the liver, determined by glutathione S-transferase placental form (GST-P), were markedly increased. Gomisin A significantly inhibited the increase in number and size of GST-P positive foci, regardless of the promotor. This lignan inhibited the increase in serum bile acid concentration by administration of DCA, but hardly influenced the serum bile acids in the PB-combined group. These results suggest that the inhibitory effect of gomisin A on the promotive action of DCA is based on improving bile acid metabolism, but regarding the action of PB, the effect could not be elucidated from the metabolism of bile acids.

Regulation of hepatic macrophage function by oral administration of xiao-chai-hu-tang (sho-saiko-to, TJ-9) in rats

The effect of Xiao-Chai-Hu-Tang (Sho-saiko-to, TJ-9), the extract of a mixture of 7 herbs, on hepatic macrophage function was studied using rats. Hepatic macrophages were activated by injection of Corynebacterium parvum or 70% partial hepatectomy. Oral administration of TJ-9 for 3 weeks did not affect the ability of these macrophages to produce superoxide anions evaluated in situ by liver perfusion with nitro blue tetrazolium (NBT) and phorbol myristate acetate (PMA). However, the similar administration of TJ-9 attenuated the blocking of the activation after partial hepatectomy produced by pretreatment with gum arabic, a polysaccharide of high molecular weight. When gum arabic was added to the medium of rat hepatic macrophages cultured with normal rat sera, their ability to produce superoxide anions was reduced in a dose-related manner. This reduction was attenuated by changing the sera to the sera obtained from rats given oral doses of TJ-9 for 3 weeks. These results suggest that TJ-9 may improve the blocked function of hepatic macrophages in activation.

Occurrence of autoimmune antibodies to liver microsomal proteins associated with lethal hepatitis in LEC rats: effects of TJN-101 ((+)-(6S,7S,R-biar)- 5,6,7,8-tetrahydro-1,2,3,12-tetramethoxy-6,7-dimethyl-10,11- methylenedioxy-6-dibenzo[a,c]cyclooctenol) on the development of hepatitis and the autoantibodies

Long Evans Cinnamon (LEC) rats, that spontaneously develop hepatitis, were found to possess autoantibodies to liver microsomal proteins (anti-LM) before the development of hepatitis. Anti-LM antibody was assumed to appear in association with the lethal hepatitis in the LEC rats. Thus, the purpose of this study was to investigate the effects of an anti-hepatitis drug on the development of hepatitis and the occurrence of the antibody in LEC rats. Mortality, blood biochemical parameters and the titer of serum anti-LM antibody were measured. In control LEC rats, 4 of 8 rats died before 20 weeks of age. In rats treated with TJN-101 ((+)-(6S,7S,R-biar)-5,6,7,8-tetrahydro-1,2,3,12-tetramethoxy -6,7-dimethyl-10,11 - methylenedioxy-6-dibenzo[a,c]cyclooctenol), 4 of 7 rats died of hepatitis, but the time of death was delayed by 7-10 weeks compared to the control rats. The titer of the anti-LM antibody increased 3-7 weeks before death in the non-survivors in control and TJN-101-treated rats, supporting the idea that anti-LM antibody occurs in association with acute lethal hepatitis.

Enzymic studies on the animal and intestinal bacterial metabolism of geniposide

Geniposide, a main iridoid glucoside of Gardenia fruit, is transformed to genipin, a genuine choleretic, in vivo in rats (Aburada et al., J. Pharmacobio-Dyn., 1, 81 (1978)). As geniposide was not hydrolyzed to any metabolite by rat liver homogenate, which has beta-D-glucosidase and esterase activities, beta-D-glucosidases in intestinal bacteria seem to be required for an exhibition of its choleretic action. The crude extract of Eubacterium sp. A-44, a human intestinal anaerobe, hydrolyzed geniposide, but that of Ruminococcus sp. PO1-3, another human anaerobe, did not, though both extracts had beta-D-glucosidase activities for p-nitrophenyl beta-D-glucopyranoside. Only one of three beta-D-glucosidases from E. sp. A-44 and none of two from R. sp. PO1-3 hydrolyzed geniposide to genipin. However, carboxylesterases from E. sp. A-44 and pig liver were unable to hydrolyze geniposide to geniposidic acid, but hydrolyzed genipin to an aglycone of geniposidic acid, indicating that geniposide is first hydrolyzed to genipin by beta-D-glucosidases and subsequently to the aglycone of geniposidic acid by esterases. Thus, when geniposide is orally administered, genipin seems to be effectively produced in the intestine and then absorbed to act as a genuine choleretic.

Inhibition by gomisin A, a lignan compound, of hepatocarcinogenesis by 3'-methyl-4-dimethylaminoazobenzene in rats

The effects of gomisin A, a lignan compound of Schizandra fruits, on hepatocarcinogenesis induced by 3'-methyl-4-dimethylaminoazobenzene (3'-MeDAB) in rats were investigated. Gomisin A inhibited both increases of the number and size of glutathione S-transferase placental form (GST-P)-positive foci, a marker enzyme of preneoplasm, and the population of diploid nuclei, as a proliferative state of hepatocytes, in the liver from rats simultaneously treated with 3'-MeDAB. Gomisin A increased GST activity in the liver, by raising the level of GST 1 and 2 isozymes. 3'-MeDAB increased GST activity and GST-P expression. This high level of GST-P induced by 3'-MeDAB was suppressed by additional treatment with gomisin A. In an experiment on simultaneous treatment, gomisin A increased the biliary excretion of 3'-MeDAB-related aminoazo dyes and decreased the content in the liver of rats fed with 0.06%-3'-MeDAB containing diet. In an experiment on pretreatment with 3'-MeDAB, even though no aminoazo dye was detectable in the liver or bile 2-weeks after cessation of 3'-MeDAB-feeding, gomisin A showed a tendency to reduce the preneoplastic changes of increases in GST-P positive foci and diploid nuclei in the liver. These results suggest that gomisin A inhibits the hepatocarcinogenesis induced by 3'-MeDAB by enhancing the excretion of the carcinogen from the liver and by reversing the normal cytokinesis.

Gomisin A, a lignan component of Schizandora fruits, inhibits development of preneoplastic lesions in rat liver by 3'-methyl-4-dimethylamino-azobenzene

The effects of gomisin A, a lignan component of Schizandra fruits, on development of preneoplastic lesions in the liver after a short-term (3 weeks) feeding of 3'-methyl-4-dimethyl-aminoazobenzene (3'-MeDAB) to male Donryu rats were investigated, and compared with the effects of phenobarbital. Gomisin A inhibited both increases of the level of glutathione-S-transferase placental form (GST-P) and the number and size of GST-P positive foci in the liver increased after treatment with 3'-MeDAB. Moreover, although the population of diploid nuclei was increased and that of tetraploid nuclei was decreased by pretreatment with 3'-MeDAB, gomisin A returned this to near the normal ploidy pattern. But phenobarbital increased the level of GST-P and the number and size of GST-P positive foci with little affect on the ploidy population changed by 3'-MeDAB. Thus, the effect of gomisin A on hepatocarcinogenesis was inhibitory in contrast with that of phenobarbital. This study suggests that gomisin A is a candidate for a chemopreventive drug inhibiting the promotion process in hepatocarcinogenesis.

Inhibition of beta-glucuronidase by natural glucuronides of kampo medicines using glucuronide of SN-38 (7-ethyl-10-hydroxycamptothecin) as a substrate

1. 7-Ethyl-10-[4-(piperidino)-1-piperidino] carbonyloxycamptothecin (CPT-11), a potent anticancer agent currently under development for clinical use, is metabolized in vivo to 7-ethyl-10-hydroxycamptothecin (SN-38), which is subsequently conjugated to 7-ethyl-10-hydroxycamptothecin glucuronide (SN-38-glucuronide). The SN-38-glucuronide was hydrolysed by beta-glucuronidase from E. coli to aglycones and glucuronic acid. 2. Four purified natural glucuronides including baicalin, wogonoside, luteolin-3'-glucuronide, and glycyrrhizin, inhibited beta-glucuronidase using SN-38-glucuronide as substrate. The inhibition potencies of these natural glucuronides toward beta-glucuronidase were similar to that of saccharic acid 1,4-lactone. 3. These results indicate that plant materials of Kampo (Japanese herbal) medicines containing these glucuronides could be used in vivo to decrease the enterohepatic circulation of SN-38 and possibly that of other drugs.

Determination of baicalin and baicalein in rat plasma by high-performance liquid chromatography with electrochemical detection

A rapid and sensitive method, using electrochemical detection, has been developed for the determination of baicalin and baicalein, the flavonoid of Scutellariae radix, in rat plasma. Following separation by high-performance liquid chromatography, baicalin and baicalein were oxidized at a glassy carbon electrode to permit selective electrochemical detection. Absolute detection limits were found to be 5 ng/ml from 50 microliters of plasma for baicalin and 2 ng/ml from 100 microliters of plasma for baicalein. The resulting assays were suitable for pharmacokinetic studies of baicalin and baicalein in rats.

Gomisin A inhibits tumor promotion by 12-O-tetradecanoylphorbol-13-acetate in two-stage carcinogenesis in mouse skin

Gomisin A, isolated from the fruits of Schisandra chinensis, is one of the dibenzocyclooctadiene lignans. Application of 12-O-tetradecanoylphorbol-13-acetate (TPA, 1 microgram/ear), a tumor-promoting agent, to the ears of mice induces inflammation. Among seven dibenzocyclooctadiene lignans assayed, gomisin A, gomisin J, and wuweizisu C inhibited the inflammatory activity induced by TPA in mice. The ED50 of these compounds for TPA-induced inflammation was 1.4-4.4 mumol. Gomisin A, with an ED50 of 1.4 mumol, showed the strongest inhibitory effect. Furthermore, at 5 mumol/mouse, it markedly suppressed the promotion effect of TPA (2.5 micrograms/mouse) on skin tumor formation in mice following initiation with 7,12-dimethylbenz[a]anthracene (50 micrograms/mouse). It is assumed that the inhibition of tumor promotion by gomisin A is due to its anti-inflammatory activity.

Effects of medicinal plants on hemopoietic cells

It has been found that Juzentaihoto (TJ-48), one of the traditional Japanese kampo (herbal) medicines, improves the general condition of cancer patients receiving chemotherapy and radiation therapy. We analyze how TJ-48 elicits such effect, and show that oral administration of TJ-48 accelerates recovery from hemopoietic injury induced by radiation and the anti-cancer drug mitomycin C. The effects are found to be due to its stimulation of spleen colony-forming units. Based on the present findings, we propose that the administration of TJ-48 should be of benefit to patients receiving chemotherapy, radiation therapy or bone marrow transplantation.

[Determination of gomisin A (TJN-101) and its metabolite in rat serum by gas chromatography-mass spectrometry]

Gomisin A (TJN-101) is one of the lignan components isolated from Schisandra Fruits. A high sensitive and precise method for the determination of TJN-101 and its major metabolite (Met. B) in the rat serum was developed by selected ion monitoring (SIM) with gas chromatography-mass spectrometry (GC/MS) using a fused silica capillary column (SPB-1, Supelco). A 100 microliter serum sample was used for the solid phase extraction. The calibration curves of TJN-101 and Met.B both showed a good linearity between 2.0 and 2000.0 ng/ml. The analytical precision (intra-assay, C.V. less than 4.7%), recoveries (98.4 +/- 10.1%), and detection limit (2 ng/ml) of TJN-101 indicated that this system was suited for the determination of TJN-101 in biological fluid. In case of Met.B, the same results as TJN-101, were obtained. After oral administration of TJN-101 at a dose of 10 mg/kg to male rats, the average values of the maximal serum concentration of TJN-101 and Met.B were 1446.1 +/- 131.8 and 317.4 +/- 18.5 ng/ml, respectively. The serum concentrations of these substances could be monitored sufficiently for 8 h after dosing.

[Studies on the metabolic fate of gomisin A (TJN-101). II. Absorption and excretion in CCl4 treated rats]

The absorption and excretion of gomisin A (TJN-101) in rats whose livers were injured by carbon tetrachloride (CCl4) were investigated. After intravenous administration of TJN-101 at a dose of 5 mg/kg, the terminal elimination half-life was 1.5 h in the CCl4-treated rats, which was two times that in normal rats. The mean area under the blood concentration-time curve (AUC) value of TJN-101 in the CCl4-treated rats was twice that in normal rats, and this difference was significant (p less than 0.05). Therefore, the total body clearance of TJN-101 in the CCl4-treated rats decreased less than half of that in normal rats. Similar results were observed when it was administered orally. In the CCl4-treated rats, the serum concentration of Met. B, which was identified as a demethylenated substance and one of major metabolites, tended to decrease more than that in normal rats. On the other hand, the cumulative biliary excretion ratio of TJN-101 in 24 h after dosing in the CCl4-treated rats was 2.5 times that in normal rats. The excretion rate of Met. B in the bile in the CCl4-treated rats tended to be delayed. However, the quantitative variance of biliary excretion of Met. B was not found in both groups. The urinary excretion of TJN-101 or Met. B in 72 h after dosing in the CCl4-treated rats was lower than that in normal rats. Similar results were also observed in excretion in the feces.(ABSTRACT TRUNCATED AT 250 WORDS)

[Studies on the metabolic fate of gomisin A (TJN-101). I. Absorption in rats]

Gomisin A (TJN-101) is one of the lignan components isolated from Schisandra Fruits and expected to have some efficacies in clinical treatment of hepatitis. The serum concentrations of TJN-101 and Met. B, which was identified as a demethylenated substance and one of the major metabolites of TJN-101 in rats, were investigated. After intravenous administration at doses of 1.6, 4.0 and 10 mg/kg of body weight, the serum concentration of TJN-101 decreased biphasically, and the terminal elimination half-life at each dose was about 70 min. Dose-dependency was observed for the area under the concentration-time curve (AUC). On the other hand, the serum concentration of TJN-101 increased rapidly and reached maximum within 15 to 30 min when administered orally. This result was supported by the in situ roop method. The Cmax and the AUC values were not exactly dose-dependent, but the values increased with a dose-up of TJN-101. The biotransformation of TJN-101 to Met. B, was very rapid in both intravenous and oral administrations. The AUC value of Met. B after oral administration of TJN-101 at a dose of 1.6 mg/kg was relatively larger than any other dosages. It suggested that TJN-101 was extensively underwent the first pass effect in rats. More than 80% of TJN-101 was bound with rat serum protein in vitro and in vivo. Therefore, it seems to be necessary to pay attention when it was administered concurrently with high protein binding drugs.

Automatic monitoring system for the measurement of body weight, food and water consumption and spontaneous activity of a mouse

The simultaneous recording system for body weight, food and water consumption and behavior (spontaneous motor activity and drinking and feeding behavior) of a mouse was developed. The body weight and food consumption were measured by force transducers. Food and water consumption and drinking and feeding behavior were measured by an infrared luminous diode and a phototransistor. Spontaneous motor activity was measured by photosensors. The system control and data acquisition were performed by using a personal computer. Every parameter could be monitored with a desired time interval. All the data collected by this system revealed apparent circadian rhythm. In conclusion, this system would be a powerful tool for pharmacological and/or toxicological research.

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).

Effect of gomisin A (TJN-101) on the arachidonic acid cascade in macrophages

It has been reported that leukotrienes (LTs) may play a role in inflammatory liver diseases, and several inhibitors of LTs show an inhibitory effect on experimental liver injuries. In this study, the effect of Gomisin A (TJN-101), which is a lignan component of schisandra fruits, on the arachidonic acid cascade in macrophages was examined to explain the mechanisms of the inhibitory effect of TJN-101 on liver injuries. The production of leukotriene B4 was suppressed by treatment with TJN-101, while the activity of 5-lipoxygenase was not affected. The release of arachidonic acid from macrophages stimulated with fMet-Leu-Phe or the Ca++ ionophore A23187 was suppressed by treatment with TJN-101. The activity of phospholipase A2 was not affected by treatment with TJN-101. These results suggested that TJN-101 produces an inhibitory effect on the biosynthesis of LTs by preventing the release of arachidonic acid, and it was thought that the preventive effect on the arachidonic acid cascade may be partially associated with the inhibitory effect of TJN-101 on liver injuries.

Synthesis of entadamide A and entadamide B isolated from Entada phaseoloides and their inhibitory effects on 5-lipoxygenase

Two new sulfur-containing amides, entadamide A (1) and entadamide B (2), isolated from the seeds of Entada phaseoloides, were synthesized by the addition reaction of methanethiol to propiolic acid (5) followed by condensation with ethanolamine by the use of dicyclohexylcarbadiimide. These compounds inhibited the 5-lipoxygenase activity of RBL-1 cells at 10(-4) g/ml. This finding suggests that entadamides A and B may be examples of a new type of antiinflammatory drug.

Rat epidermal growth factors: purification and tissue content

Rat epidermal growth factor (rEGF) was isolated from the submaxillary gland of male rat by reversed phase high performance liquid chromatography and ion exchange chromatography. The binding of purified rEGF to human carcinoma cells (A-431) and its tritiated thymidine uptake on rat epidermal fibroblast cells (FR) were almost the same as those of purified commercially available mouse EGF (mEGF). Antisera to rEGF was raised in rabbits and a radioimmunoassay (RIA) system was established. The assay range of the RIA was about 1.0 to 100 ng/ml. The within assay coefficients of variation were 5 to 10%, while the between assay coefficients of variation were 5 to 13%. The tissue content of rEGF of male rats (10 weeks old) was examined. As a result, the submaxillary gland was found to contain a very high concentration of rEGF (214 micrograms/g wet tissue) as predicted, and digestive tissues, stomach, intestine and duodenum contained 2.49, 3.57, 9.44 ng/g wet tissue, respectively. The amounts in prostate and seminal vesicle were relatively high, being 65.6 and 2,268 ng/g wet tissue, respectively. The amount in the submaxillary gland increased markedly after 7 weeks of age. These results suggest that EGF is an important factor in gonadal function.

[Effects of TJ-41 (Tsumura Hochu-ekki-to) on spermatogenic disorders in mice under current treatment with adriamycin]

Experiments were performed to investigate the effects of TJ-41 on spermatogenic disorders under current treatment with adriamycin (ADR). Male ICR mice were intraperitoneally injected with ADR at the dose of 0.15 mg/kg, twice a week for 5 weeks. Simultaneously, these mice were orally administered TJ-41 at the dose of 1, 2 or 4 g/kg for 12 weeks. The effects of TJ-41 were evaluated by histological analysis of germ cells in the testis at 7 weeks after the last injection of ADR. TJ-41 at a dose of 4 g/kg significantly inhibited the decrease of testis weight in mice treated with ADR. TJ-41 at doses of 1 and 4 g/kg significantly decreased the proportion of seminiferous tubules without germ cells as compared with the ADR-treated group. On the other hand, TJ-41 at doses of 1 and 4 g/kg significantly increased the proportion of normal seminiferous tubules and the Sertoli cell ratio of spermatocytes as compared with the ADR-treated group. These results indicate that TJ-41 may qualitatively and quantitatively protect against the decrease of germ cells in the testis of mice treated with ADR.

A two-site solid phase enzyme immunoassay for rat epidermal growth factor

A sensitive and simple two-site enzyme immunoassay was developed for rat epidermal growth factor (rEGF), which was purified from male rat submaxillary glands. This system is based on the sandwiching of the antigen between anti-rat EGF IgG antibody coated on a polystyrene bead and anti-rat EGF Fab' antibody-linked peroxidase, whose activity was stable at 4 degrees C for 6 months. In this system, the rat EGF was detectable at a concentration of 2 pg/tube. No interference was observed by addition of human plasma. There was no cross-reactivity with mouse EGF, human EGF, or other substances with similar chemical structures.

[Effect of gomisin A (TJN-101), a lignan compound isolated from Schisandra fruits, on liver function in rats]

TJN-101 [+)-(6S, 7S, R-biar)-5,6,7,8-tetrahydro-1,2,3,12-tetramethoxy- 6,7-dimethyl-10,11-methylenedioxy-6-dibenzo [a, c] cyclooctenol) is one of the lignan compounds isolated from Schisandra fruits. When TJN-101 was administered orally at the doses of 3-100 mg/kg/day for 4 days, bile secretion, hepatic excretion of dye or hepatic hemodynamics 24 hr after the last dose was investigated in comparison with the phenobarbital (100 mg/kg/day)-treated group. Bile flow was dose-dependently increased; in contrast, biliary concentration of bile acids was decreased in TJN-101 (30 and 100 mg/kg/day)-treated groups. Similar changes were also observed in the phenobarbital-treated group. These results suggested that the enhancement of bile secretion caused by TJN-101 or phenobarbital was due to an increase of a bile acid-independent fraction. In the bromosulfophthalein (BSP) clearance test for liver function, both TJN-101 (30 and 100 mg/kg/day) and phenobarbital accelerated the disappearance from the blood and biliary excretion of BSP. Hepatic hemodynamics was examined by the hydrogen clearance method and measurement of liver wet and dry weight. Liver blood flow tended to increase in the TJN-101 (10-100 mg/kg/day) or phenobarbital-treated group. On the other hand, TJN-101 (3-100 mg/kg/day) or phenobarbital hardly altered the water content of the liver. These results suggested that the liver enlargement caused by both compounds was not accompanied with hepatic edema and that the enhancement of bile secretion or hepatic excretion of BSP might be related to an increase of liver blood flow.

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.

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.

[Effects of TJN-101, a lignan compound isolated from Schisandra fruits, on liver fibrosis and on liver regeneration after partial hepatectomy in rats with chronic liver injury induced by CCl4]

TJN-101 ((+)-(6S,7S,R-biar)-5,6,7,8-tetrahydro-1,2,3,12-tetramethoxy -6,7-dimethyl-10,11-methylenedioxy-6-dibenzo[a,c]cyclooctenol) is one of the lignan compounds isolated from Schisandra fruits. 1) Effect of TJN-101 on liver fibrosis was investigated in rats which were injected with CCl4 (1 ml/kg) subcutaneously twice a week for 12 weeks. TJN-101 was given orally at the dose of 10 or 30 mg/kg/day for 6 or 3 weeks beginning on the 6th or 9th week after the start of CCl4-intoxication, respectively. The elevations of serum transaminase activities and the increase of liver 4-hydroxyproline content were observed depending on the period of CCl4-intoxication. These changes were marked on the 9th and 12th weeks after. In the histopathological study, the degenerative fatty change on the 6th week after and the formation of pseudolobule caused by fibrosis proliferation on the 9th or 12th week after were mainly observed. When rats were treated with TJN-101, the abnormalities in biochemical parameters and the fibrosis proliferation caused by CCl4-intoxication were improved. 2) Chronic liver injury was induced by the treatment with CCl4 (1 ml/kg) subcutaneously twice a week for 10 weeks to investigate the effect of TJN-101 on liver regeneration after partial hepatectomy. TJN-101, which was given orally at the dose of 10, 30 or 100 mg/kg/day for 6 days from the 1st day after partial hepatectomy, dose-dependently increased the liver regeneration rate and improved the serum BSP retention rate. These results suggest that TJN-101 suppresses the fibrosis proliferation and accelerates both the liver regeneration and the recovery of liver function after partial hepatectomy in chronic liver injury.

[Pharmacological study of TJ-8007 (Tsumura-Zokumeito) (I): Protective effects of TJ-8007 against anoxic brain damage]

The protective effects of TJ-8007 (Tsumura-Zokumeito, Traditional chinese medicine) against cerebral anoxia were investigated with various experimental models in mice and rats. 1) In histotoxic anoxia, TJ-8007 (0.3-3.0 g/kg, p.o.) dose-dependently demonstrated a protective effect on coma induced by a sublethal dose of KCN (1.8 mg/kg, i.v.) in mice. Ifenprodil (30 mg/kg, p.o.) tended to reduce the coma time, but papaverine (100 mg/kg, p.o.) showed a negative effect. 2) TJ-8007 (0.3-3.0 g/kg, p.o.) dose-dependently tended to prolong the survival time of mice subjected to a lethal dose of KCN (3.0 mg/kg, i.v.), TJ-8007 also improved the survival rate at the dose of 3.0 g/kg. Ifenprodil (30 mg/kg, p.o.) or papaverine (100 mg/kg, p.o.) exerted a similar effect on the survival time, but did not affect the mortality. 3) In the normobaric hypoxia with a gas mixture of 96% N2 and 4% O2, TJ-8007 (0.3-3.0 g/kg, p.o.) did not affect the survival time of mice. On the other hand, papaverine (100 mg/kg, p.o.) prolonged the survival time, and phenytoin (100 mg/kg, p.o.) showed a marked protective effect, but ifenprodil (30 mg/kg, p.o.) produced an adverse effect. 4) In the asphyxic anoxia induced by stopping artificial respiration of immovable rats, TJ-8007 (1.0, 3.0 g/kg, p.o.) showed a protective effect on the fall of systemic blood pressure and on the decline of heart rate; furthermore, it dose-dependently prolonged the disappearance time of cortical activity. Also, phenytoin (100 mg/kg, p.o.) tended to protect against the fall of blood pressure and prolonged the cortical resistance time.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibitory effect of TJN-101 ((+)-(6S,7S,R-biar)-5,6,7,8-tetrahydro-1,2,3,12-tetramethoxy -6,7-dimethyl-10,11- methylenedioxy-6-dibenzo[a,c]cyclooctenol) on immunologically induced liver injuries

TJN-101, which is a lignan component isolated from schisandra fruits, inhibits hepatotoxic chemicals-induced liver injuries. In this study, effects of TJN-101 on immunologically induced liver injuries were investigated in vivo and in vitro. When a small dose of lipopolysaccharide was injected into mice previously injected with heat-killed Propionibacterium acnes, most of the animals died with acute hepatic failure which was produced by cytotoxic factors from activated adherent cells, and liver cells were injured by antibody-dependent cell-mediated cytotoxic (ADCC) reaction or activated macrophages in vitro. TJN-101 reduced the mortality of the mice with acute hepatic failure dose-dependently. Histologically, necrosis was suppressed by the treatment of TJN-101, but infiltration of non-specific inflammatory cells was not. TJN-101 inhibited the isolated liver cell injuries induced by ADCC reaction or activated macrophages in vitro. These results suggest that TJN-101 can be markedly protective against immunological liver injuries.

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.

[Pharmacological studies on ginger. V. Pharmacological comparison between (6)-shogaol and capsaicin]

Pharmacological actions of (6)-shogaol and capsaicin were studied. Both (6)-shogaol (0.5 mg/kg, i.v.) and capsaicin (0.1 mg/kg, i.v.) caused a triad such as a rapid fall in blood pressure, bradycardia and aponea in rats. Both drugs-induced marked pressor responses in blood pressure, which occurred after the rapid fall, were markedly reduced by a spinal destruction. In pithed rats, both drugs-induced peripheral pressor responses were markedly reduced with the combined treatment of [D-Arg1, D-Pro2, D-Trp7,9, Leu11]-substance P (0.5 mg/kg, i.v.), phentolamine (10 mg/kg, i.v.) and the section of sciatic nerves. In isolated guinea-pig trachea, (6)-shogaol (100 microM) and capsaicin (10 microM) induced contractile responses which were slightly inhibited by substance P antagonist (10 microM), but exhibited also a tachyphylaxis. Furthermore, although (6)-shogaol (3.6 microM) showed positive inotropic and chronotropic actions on isolated atria in rats, this effect of (6)-shogaol disappeared by repeated injections or pretreatment (100 mg/kg, s.c.) of (6)-shogaol. These results suggest that (6)-shogaol and capsaicin have similar actions, and that both drugs may cause a peripheral action by releasing an unknown active substance from nerve ends.

[Pharmacological studies on ginger. IV. Effect of (6)-shogaol on the arachidonic cascade]

(6)-Shogaol, a pungent component of ginger, which is contained in semi-dried ginger but is rarely found in fresh ginger inhibited carrageenin-induced swelling of hind paw in rats and arachidonic acid (AA)-induced platelet aggregation in rabbits. Moreover, (6)-shogaol prevented prostaglandin I2 (PGI2) release from the aorta of rats when tested as an inhibitor of platelet aggregation. These results suggest that (6)-shogaol may have an inhibitory action on the cyclo-oxygenases in both platelets and aorta. Examination of the effects of (6)-shogaol on cyclo-oxygenases in rabbit platelets and microsome fractions of rat aorta indicated that (6)-shogaol inhibited cyclo-oxygenase activities of both tissues in a concentration-dependent manner. Furthermore, when we examined the effect of (6)-shogaol on 5-lipoxygenase from RBL-1 cells, (6)-shogaol exhibited an inhibitory action on 5-lipoxygenase activity. Therefore, it seems that the inhibitory effects of (6)-shogaol on the carrageenin-induced paw edema, AA-induced platelet aggregation and PGI2 production of aorta may be caused by the inhibition of cyclo-oxygenase activity.

Pharmacological studies on ginger. II. Pressor action of (6)-shogaol in anesthetized rats, or hindquarters, tail and mesenteric vascular beds of rats

When (6)-shogaol (0.5 mg/kg, i.v.) was administered to rats, blood pressure showed a tri-phasic response which was comprised of a rapid fall, followed by a rise and a delayed fall. The rapid fall, which followed immediately after injection of (6)-shogaol, disappeared with the use of atropine and vagotomy. The marked rise, which occurred after the rapid fall, was not affected by alpha-adrenoceptor blockades, Ca antagonists and ganglion blockade. However, a combination of alpha-adrenoceptor blockade and Ca antagonist inhibited this pressor response. In hindquarters perfused with a nutrient solution, (6)-shogaol (10(-5) g)-induced peripheral pressor response was also not affected by alpha-adrenoceptor blockades and Ca antagonists, but was inhibited by the combination of an alpha-adrenoceptor blockade and a Ca antagonist. Furthermore, this peripheral pressor response was eliminated by the removal of Ca ion from the perfusate. (6)-Shogaol did not exhibit a pressor response in an artery and a vein of the tail or an artery of the femur perfused with a nutrient solution. (6)-Shogaol-induced peripheral pressor response in hindquarters was markedly potentiated during the perfusion of norepinephrine (5 X 10(-6) g/ml), but this potentiation was prevented by pretreatment with reserpine (5 mg/kg, i.p.). Moreover, repeated injections of (6)-shogaol caused a tachyphylaxis in mesenteric and tail vascular beds and a slight tachyphylaxis in hindquarters.

[Effects of TJN-101 ((+)-(6s,7s,R-biar)-5,6,7,8-tetrahydro-1,2,3,12-tetramethoxy-6,7 -dimethyl-10,11-methylenedioxy-6-dibenzo [a,c] cyclooctenol) on liver regeneration after partial hepatectomy, and on regional hepatic blood flow and fine structure of the liver in normal rats]

Effects of TJN-101, one of the components isolated from Schizandra fruits, on liver regeneration after partial hepatectomy, and on regional hepatic blood flow and fine structure of the liver were investigated in normal rats. TJN-101, which was administered orally at the doses of 10, 30 and 100 mg/kg/day for 4 days after partial hepatectomy, increased the regeneration rate of the liver and improved the serum retention rate of BSP which had been dose-dependently decreased after the operation. Elevation of serum protein to control levels, elevation of serum LCAT activity, decrease in plasma insulin and increase in plasma glucagon were all dose-dependent responses to TJN-101. The mitotic index on the 5th day after the operation was hardly influenced by TJN-101. Regional hepatic blood flow was increased after intraduodenal administration of TJN-101 (30 and 100 mg/kg). Ultrastructural studies of liver tissue using the transmission electron microscope revealed that TJN-101 stimulated an increase in rough and smooth endoplasmic reticulum in the groups receiving 100 and 300 mg/kg/day. These results suggest that TJN-101 accelerates both the proliferation of hepatocytes and the recovery of liver function after partial hepatectomy and increases hepatic blood flow. It is also thought that the liver enlargement caused by repeated administration of TJN-101 is associated with the proliferation of endoplasmic reticulum.

Pharmacological studies on ginger. III. Effect of the spinal destruction on (6)-shogaol-induced pressor response in rats

(6)-Shogaol-induced pressor responses in blood pressure of rats were studied. Intraventricular injection of (6)-shogaol (0.1 to 0.5 microgram) caused a pressor response in a dose-dependent manner. (6)-Shogaol (0.5 mg/kg, i.v.)-induced pressor response was markedly reduced by a spinal destruction to the sacral cord level. However, norepinephrine (10 micrograms/kg, i.v.)-induced pressor response was not affected by the spinal destruction. In rats in which the spinal cord was destroyed to the thoracic cord level, (6)-shogaol-induced pressor response was reduced by hexamethonium (10 mg/kg, i.v.) and phentolamine (10 mg/kg, i.v.), etc. When the spinal cord was destroyed to the sacral cord level, the pressor response was not affected by these blockades. In the hindquarters of rats which were perfused with rats' blood, (6)-shogaol caused two pressor responses on the perfusion pressure. The first pressor response, which was accompanied by a rise in systemic blood pressure, was reduced by hexamethonium but was not entirely eliminated by phentolamine. However, the pressor response disappeared with spinal destruction to the sacral cord level. The second pressor response, which occurred about when the systemic blood pressure regained its original pressure, was not affected by hexamethonium, phentolamine or spinal destruction. Pressor response induced by the injection of (6)-shogaol (10 micrograms) into the perfusion circuit was not affected by phentolamine and spinal destruction. Furthermore, (6)-shogaol-induced peripheral pressor response disappeared with the combined treatment of [D-Arg1, D-Pro2, D-Trp7.9, Leu11]-substance P (0.5 mg/kg, i.v.), phentolamine and the section of the sciatic nerves.