Possible involvement of nitric oxide synthase in oxidative stress-induced endothelial cell injury

The purpose of this study was to characterize the protective effect of NG-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthase, on oxidative stress-induced endothelial cell injury. Intracellular oxidative stress was induced by 1-chloro-2,4-dinitrobenzene, a glutathione (GSH) depleting agent, and the leakage of intracellular lactate dehydrogenase was measured as a marker of cell injury. Addition of 1-chloro-2,4-dinitrobenzene (100-500 microM) induced leakage of lactate dehydrogenase from endothelial cells, and the leakage of lactate dehydrogenase was strongly attenuated by L-NAME, but not by NG-methyl-L-arginine, also an inhibitor of nitric oxide synthase. However, cell injury induced by the Ca2+ ionophore ionomycin was not affected by L-NAME or NG-methyl-L-arginine. Moreover, neither L-NAME nor NG-methyl-L-arginine affected GSH depleting agent-induced or H2O2-induced cell injury in a rat foetal lung fibroblast cell line which lacks nitric oxide synthase. These results suggest that the protective effect of L-NAME is likely to be related to nitric oxide synthase, while the inhibition of nitric oxide production may not be involved in the protective effect of L-NAME, since NG-methyl-L-arginine did not affect endothelial cell injury.

Identification of cytochrome P450 isoforms involved in citalopram N-demethylation by human liver microsomes

Studies to assess the enzyme kinetic behavior and to identify the cytochrome P450 (CYP) isoform(s) involved in the major metabolic pathway (N-demethylation) for citalopram (CIT), a selective serotonin reuptake inhibitor, were performed using human liver microsomes and cDNA-expressed human cytochrome P450 isoforms. The N-demethylation activities showed significant correlations with the alpha- and 4-hydroxylation activities of triazolam (r(s) = 0.818 and 0.851, respectively; P < .01) in 10 different human liver microsomes. Anti-CYP3A antibodies and ketoconazole strongly inhibited CIT N-demethylation. In addition, there was a significant correlation between CIT N-demethylation and (S)-mephenytoin 4'-hydroxylation (r(s) = 0.773, P < .05), although little inhibition was observed in the presence of anti-CYP2C antibodies or (S)-mephenytoin. cDNA-expressed CYP3A4 and CYP2C19 catalyzed CIT N-demethylation, whereas no appreciable activities were observed for CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2D6 and CYP2E1. The percentage contributions of CYP3A4 and CYP2C19 to the overall N-demethylation of CIT in human liver microsomes were estimated using a relative activity factor; respective values of 70% and 7% were calculated for microsomes obtained from livers from putative extensive metabolizers for (S)-mephenytoin 4'-hydroxylation. These results suggest that CYP3A4 is the major isoenzyme and CYP2C19 is the minor form involved in the major metabolic pathway for CIT in human liver microsomes.

Combined use of detachable coil against persistent mechanical hemolysis after transcatheter occlusion using Rashkind umbrella device in adult patient with patent ductus arteriosus

Mechanical hemolysis after transcatheter occlusion of the patent ductus arteriosus using the Rashkind umbrella device has been postulated as a rare, but serious complication, even necessitating surgical repair. A rare, case of an adult patient with massive hemolytic anemia, successfully controlled by the combined use of several detachable coil devices is reported. The use of coil devices might be considered as a therapeutic option in such cases.

Acceleration of oxidative stress-induced endothelial cell death by nitric oxide synthase dysfunction accompanied with decrease in tetrahydrobiopterin content

The purpose of this study was to examine whether nitric oxide (NO) synthase dysfunction accompanied with decrease in tetrahydrobiopterin (BH4) content increases H2O2-induced endothelial cell death. Endothelial cell death was measured by the release of intracellular lactate dehydrogenase (LDH). Intracellular BH4 content was changed by pretreatment with 2,4-diamino-6-hydroxypyrimidine (DAHP), an inhibitor of GTP cyclohydrolase I, or pretreatment with sepiapterin, a substrate for the salvage pathway of BH4 synthesis, and the intracellular content was measured by high performance liquid chromatography equipped with a fluorescence detector. Moreover, production of superoxide was detected by a chemiluminescence technique using MCLA, a Cypridina luciferin analogue, for the superoxide-sensitive probe. Pretreatment with DAHP (10 mM) for 24 h decreased intracellular BH4 content to 14% and increased H2O2-induced cell death. The toxic effect of DAHP was reduced by co-pretreatment with sepiapterin (100 microM) or treatment with N(G)-nitro-L-arginine methyl ester (L-NAME, 1 mM), an inhibitor of NO synthase, but not by N(G)-methyl-L-arginine (L-NMA, 1 mM), the other inhibitor of NO synthase. Moreover, production of superoxide in endothelial cells induced by Ca2+-ionophore ionomycin (1 microM) increased by the pretreatment with DAHP, and the increase in superoxide production was blocked by L-NAME (1 mM) but not L-NMA (1 mM). Co-pretreatment with sepiapterin decreased the production of superoxide. These findings suggested that dysfunction of NO synthase with a decrease in BH4 content in endothelial cells produced superoxide instead of NO and increased the oxidative stress-induced endothelial cell death.

Bufalin inhibits endothelial cell proliferation and angiogenesis in vitro

We have investigated the effects of bufalin, one of the prominent components in Chinese toad venom, on proliferation of bovine aortic endothelial (BAE) cells and tube formation in three-dimensional type I collagen matrix. In the present study, bufalin potently inhibited the formation of capillary-like tubular networks in a dose-dependent manner. Bufalin also inhibited the proliferation of BAE cells at the same concentration (5 nM) that the tube formation was inhibited. As a potent inhibitor of endothelial cell proliferation, bufalin specifically prevented the entry of BAE cells into the G0/G1 phase of a cell cycle. These findings suggest that in vitro angioinhibitory action of bufalin may be induced by the proliferation inhibition of endothelial cells through the arrest at the G2/M phase of a cell cycle.

Role of human cytochrome P4502A6 in C-oxidation of nicotine

Nicotine is primarily metabolized to cotinine in humans. In this study, human cytochrome P450 (CYP) isoform involved in cotinine formation was identified. The formation of cotinine in 16 human liver microsomes was determined with a 50 microM nicotine concentration and with a cytosol preparation as a source of aldehyde oxidase. Cotinine formation in human liver microsomes significantly correlated with immunochemically determined CYP2A6 levels (r = 0.663, p < 0.05), coumarin 7-hydroxylase activities (r = 0.831, p < 0.01), and cotinine 3'-hydroxylase activities (r = 0.735, p < 0.01) that are responsible for CYP2A6. In inhibition studies, cotinine formation in human liver microsomes was inhibited by coumarin and rabbit anti-rat CYP2A1 antibody specifically. When the capability of microsomes of B-lymphoblastoid cells expressing human CYPs to perform biotransformation of nicotine to cotinine was determined, cDNA-expressed CYP2A6 exhibited the highest cotinine formation. The KMapp values from microsome expressing CYP2A6 cDNA were similar to the value obtained from human liver microsomes. The large interindividual variabilities in cotinine formation and immunochemically determined CYP2A6 levels were observed in human liver microsomes, suggesting genetic polymorphism of CYP2A6. Nicotine is a new in vivo probe for phenotyping of CYP2A6 in humans.

Photodynamic therapy with a diode laser for implanted fibrosarcoma in mice employing mono-L-aspartyl chlorin E6

The authors performed photodynamic therapy (PDT), avoiding any hyperthermic effects, using a newly developed diode laser and photosensitizer, mono-L-aspartyl chlorin e6 (NPe6), of Meth-A fibrosarcoma implanted in mice and achieved tumor therapeutic benefit. The photodynamic light treatment was performed 5 h following the photosensitizer administration. With 5.0 mg/kg NPe6 and light doses of 50, 100, 150 and 200 J/cm2, the tumor cure rates were 20, 50, 70 and 90%, respectively. With 100 J/cm2 laser exposure and NPe6 doses of 1.25, 2.5, 5.0, 7.5 and 10.0 mg/kg, the tumor cure rates were 0, 20, 50, 70 and 90%, respectively. A charge-coupled device (CCD) camera system was employed to measure the NPe6 fluorescence intensity correlating with the residual amount of the photosensitizer at deferent depth from the tumor surface. The ratios of the NPe6 fluorescence intensity at 3 mm from the tumor surface following 50, 100, 150 and 200 J/cm2 laser exposure to no laser exposure were 0.73, 0.36, 0.22 and 0.16, respectively. With samples sectioned at 1 mm depth, after 50 J/cm2 and the same photosensitizer dose (5 mg/kg) this ratio was 0.19. These results suggest that a certain increase in the tumor tissue level of NPe6 and a certain increase of laser light dose reaching deeper layer of tumor caused an increase in percent cure. In addition, the effectiveness of PDT depends on the total laser dose reaching deeper layers of tumors. Furthermore, the effectiveness of PDT tends to correlate with the amount of NPe6 photobleaching by PDT.

Determination of ester-type local anesthetic drugs (procaine, tetracaine, and T-caine) in human serum by wide-bore capillary gas chromatography with nitrogen-phosphorus detection

A sensitive method for simultaneous determination of ester-type local anesthetic drugs (procaine, tetracaine, and T-caine) has been developed using wide-bore capillary gas chromatography with nitrogen-phosphorus detection (GC-NPD). The extraction procedure, the experimental conditions for heptafluorobutyryl (HFB) derivative formation, and the percentage of the ester-type local anesthetic drugs from the human serum are described. The HFB derivatives of ester-type local anesthetic drugs showed sensitivity of approximately 2-3 fold higher than that without derivatization. The detection limits of HFB derivatives of the ester-type local anesthetic drugs were approximately 60-70 pg on column. Recoveries from the human serum were 85-94%. This method could be used to determine concentrations as low as 24-28 ng/mliters of the ester-type local anesthetic drugs.

Enzyme-linked immunosorbent assay and latex agglutination inhibition reaction test for morphine in urine

An enzyme-linked immunosorbent assay (ELISA) and a latex agglutination inhibition reaction test (LAIRT) for morphine have been established. Rabbits were immunized with 3-carboxymethylmorphine-bovine serum albumin (BSA) conjugate to obtain anti-morphine antibody and IgG fraction of the antiserum was used as an antibody. In ELISA, 3-carboxymethylmorphine-alkaline phosphatase (ALP) conjugate and antibody adsorbed on polystyrene microtiter wells were used. The enzyme activity of antibody bound ALP was measured with the enzyme cycling method. The range of morphine measurable by ELISA was 6-600 pg/well and the analysis time for 96 wells was 90 min. In LAIRT, 3-carboxymethylmorphine-rabbit serum albumin (RSA) conjugate and the antibody were bound to latex particles covalently to prepare latex-antigen and latex-antibody reagent, respectively. The agglutination reaction with latex-antigen and latex-antibody reagents was inhibited by 0.2 microgram morphine/ml urine and the analysis time for six samples on one glass slide was 20 min. The urine samples of 47 suspected abusers were analyzed by ELISA and LAIRT and the results were compared with those of the enzyme-multiplied immunoassay technique (EMIT) and gas chromatography/mass spectrometry (GC/MS). Both ELISA and LAIRT for morphine seem to be suitable for the screening of urine samples.

Inhibition of insulin-induced chondrogenic differentiation of embryonic carcinoma cells by a teratogenic compound YM9429

A teratogenic compound cis-1-[4-(p-menthane 8-yloxy)phenyl]piperidine (YM9429) induces cleft palate selectively in rat fetuses. The effect of YM9429 on chondrogenic differentiation was investigated using mouse embryonic carcinoma ATDC5 cells that produce chondrocyte specific extracellular matrix upon insulin stimulation. YM9429 at concentrations that showed no growth-inhibitory effect on logarithmic proliferating cells suppressed insulin-mediated increases in Alcian blue staining and expression of type II collagen almost completely. Under the identical conditions, insulin-stimulated cell growth was only partially blocked by the compound. The early response genes such as c-fos and c-jun were induced by insulin even in the presence of YM9429. On the other hand, YM9429 inhibited accumulation of cAMP during the differentiation process. These results indicate that YM9429 selectively inhibits in vitro chondrogenic differentiation of ATDC5 cells.

A cardiotonic steroid bufalin-induced differentiation of THP-1 cells. Involvement of Na+, K(+)-ATPase inhibition in the early changes in proto-oncogene expression

Human monocytic leukemia THP-1 cells were induced to differentiate into macrophage-like cells by treatment with cardiotonic steroid bufalin, which was previously shown to interact with the Na+, K+-ATPase with similar kinetics to ouabain, a specific inhibitor of the enzyme. This induction of differentiation was characterized by loss of proliferation, cell adherence, increased ability to reduce Nitro Blue tetrazolium (NBT), and increased expression of interleukin 1 beta (IL-1 beta). During this process, bufalin downregulated c-myb and c-myc expressions and induced c-fos and Egr-1 transcripts. Ouabain also caused similar changes in proto- oncogene expression and induced phenotypic markers of differentiated cells at concentrations comparable to bufalin. The 12-O-tetradecanoyl phorbol-13-acetate resistant THP-1 cell variant, which was unresponsive to this agent as to growth inhibition and proto-oncogene expression, responded to bufalin. The finding that protein kinase inhibitor H7 failed to bufalin-mediated c-fos induction further supports the theory that the signal transduction machinery caused by bufalin is separable from the phorbol ester. The cytotoxic effect of high doses of bufalin apparently disappeared in the medium where Na+ was replaced with choline ions. Furthermore, bufalin failed to induce c-fos expression and to downregulate c-myb transcripts in the low-Na+ medium. These findings indicate that an increased intracellular Na+ concentration resulting from the Na+, K(+)-ATPase inhibition possibly triggers the change in proto-oncogene expression evoked by bufalin.

Changes of IgE production in senescence-accelerated mice SAMP8

The IgE production and proliferation activity of spleen B cells were studied in vivo in 2 approximately 3-month-old (designated as young) and 12 approximately 13-month-old (designated as old) senescence-accelerated mice (SAMP8) employing age-matched AKR mice, the origin of the SAM strain, as controls. After the secondary immunization with 2,4-dinitrophenylovalbumin conjugate (DNP-OVA) with aluminum hydroxide gel (alum) as an adjuvant, the serum IgE levels were significantly reduced in old SAMP8 compared to young SAMP8 mice, but there were no changes in AKR. However, old SAMP8 mice had a proliferative activity of spleen B cells comparable to that found in young SAMP8; proliferative activity was measured by 3H-thymidine incorporation into the spleen after stimulation with water extract from wood chips of coniferous splash pine (pine wood extract) as a mitogen. These data indicate that a decline in IgE production is a characteristic phenomenon of SAMP8 mice and was not due to the functional deficiency of B cells with aging.

Forensic immunochemistry

Immunoassay has been established with polyclonal or monoclonal antibody even for a low molecular weight compound which has no antigenicity. In spite of the cross-reactivities of an antibody and also the difficulty in identification of the compound, an immunoassay is a useful method of choice for the detection of the compound in biological fluids because of the pretreatment simplicity and ability to treat many samples in a short time. Therefore, immunoassay has been established as a sensitive analytical and screening method for use in forensic sciences. In our laboratory, a radioimmunoassay (RIA) and an enzyme immunoassay (EIA) for phenobarbital, and enzyme-linked immunosorbent assays (ELISA) and latex agglutination inhibition reaction tests (LAIRT) for methamphetamine, benzoylecgonine and morphine have been established. These assays are described in addition to the two commercially available immunoassay kits, enzyme multiplied immunoassay technique (EMIT; Syva Co., USA) and Triage Biosite Piagnostics, Inc, USA.

The cooperative interaction of two different signaling pathways in response to bufalin induces apoptosis in human leukemia U937 cells

Bufalin, an active principle of Chinese medicine, chan'su, induced typical apoptosis in human leukemia U937 cells. When U937 cells were treated with 10(-8) M bufalin in the absence of serum, mitogen-activated protein (MAP) kinase activity was markedly increased 6 h after the start of treatment and elevated so for 12 h. Prior to the activation of MAP kinase, increased activities of Ras, Raf-1, and MAP kinase kinase were found, but these enzymes were transiently activated by the treatment with bufalin. These results suggest that the signal was transmitted sequentially from Ras, Raf-1, and MAP kinase kinase to MAP kinase. In association with this signal transduction, the concentration of cAMP in the cells decreased markedly, suggesting that Raf-1 was also activated by a decrease in the extent of phosphorylation by protein kinase A. In fact, pretreatment of U937 cells with forskolin and 3-isobutyl-1-methylxanthine, which are known to increase the concentration of cAMP in the cells, and subsequent treatment with bufalin resulted in a decrease in both Raf-1 activity and DNA fragmentation. To confirm the participation of MAP kinase in the apoptotic process, antisense cDNA for MAP kinase kinase 1 was expressed in U937 cells. The transformants were significantly resistant to both DNA fragmentation and cell death in response to bufalin. Our findings suggest that a pathway with the persistent activation of MAP kinase in U937 cells in response to bufalin is at least one of the signal transduction pathways involved in the induction of apoptosis.

Characterization of CYP2A6 involved in 3'-hydroxylation of cotinine in human liver microsomes

Nicotine is primarily metabolized to cotinine, and cotinine is further metabolized to trans-3'-hydroxycotinine in human liver, which is a major metabolite of nicotine in humans. We studied the formation of trans-3'-hydroxycotinine from cotinine in human liver microsomes. trans-3'-Hydroxycotinine formation demonstrated single enzyme Michaelis-Menten kinetics (Km, 234.5 +/- 26.8 MicroM; Vmax, 37.2 +/- 2.4 pmol/min/mg protein). Significant correlation (r = .967, P < .001) between cotinine 3'-hydroxylase activities at low (50 microM) and high (1 microM) cotinine concentrations in 20 human liver microsomes suggested the contribution of a single enzyme to cotinine 3'-hydroxylation. The cotinine 3'-hydroxylase activity correlated significantly with immunoreactive cytochrome P450 (CYP)2A6 contents (r = .756, P < .01) and coumarin 7-hydroxylase activity (r = .887, P < .001). The cotinine 3'-hydroxylase activity was inhibited by coumarin, alpha-naphthoflavone, chlorzoxazone and anti-rat CYP2A1 antibodies. Microsomes of B-lymphoblastoid cells expressing human CYP2A6 exhibited cotinine 3'-hydroxylase activity. The Km value of the expressed CYP2A6 (264.7 microM) was almost identical to that of human liver microsomes. In conclusion, cotinine 3'-hydroxylation appears to be catalyzed solely by CYP2A6 in humans. Cotinine is a candidate for a new substrate for CYP2A6 in humans.

Enzyme-linked immunosorbent assay and latex agglutination inhibition reaction test for cocaine and benzoylecgonine in urine

An enzyme-linked immunosorbent assay (ELISA) and a latex agglutination inhibition reaction test (LAIRT) for cocaine and benzoylecgonine have been established. In ELISA with polystyrene microtiter wells coated with anti-benzoylecgonine antibody and alkaline phosphatase (ALP)-labeled benzoylecgonine, the activity of antibody-bound ALP was measured with the enzyme cycling method. The range of benzoylecgonine measurable by ELISA was 12 pg-25 ng/well; the analysis time for 96 wells was 90 min. In LAIRT, the agglutination reaction with anti-benzoylecgonine antibody-coated latex and benzoylecgonine-rabbit serum albumin (RSA) conjugate-coated latex was inhibited by 0.1 mu g benzoylecgonine/ml urine; the analysis time for six samples on one glass slide was 20 min. The urine samples of 47 abusers were analyzed by ELISA and LAIRT. From the comparison with results of the enzyme-multiplied immunoassay technique (EMIT) and gas chromatography-mass spectrometry (GC-MS), it was clarified that both ELISA and LAIRT were suitable for the screening method of urine samples.

[Use of cortical SEP for the prediction of neurological prognosis after cardiopulmonary resuscitation]

The improved technique of cardiopulmonary resuscitation (CPR) resulted in survival of many patients who had experienced cardiopulmonary arrest (CPA). However, when the recovery of brain function is poor, patients suffer from severe neurological sequelae, including persistent vegetative state. There have been no conclusive methods to predict the outcome of anoxic encephalopathy after CPR. Madl et al (1993) recorded cortical SEP over the parietal scalp electrodes after bilateral median nerve stimulation at the wrists in anoxic patients experiencing CPR. Their results indicated that the median SEP is useful for the early prediction of neurological prognosis after CPR. We studied short and long latency cortical SEPs evoked by the left median nerve stimulation in 18 consecutive anoxic patients within 48 hours after CPR. The absence of N20, N35, P45 indicated mortality of 86.4% (100% in Madl's results). Preserved N60 peak indicated the recovery of consciousness, while Madl's results showed that patients did not regain consciousness when the N60 latency was longer than 121 ms. Neurological prognosis showed the significant correlation with N20, P25 amplitude and not with amplitude ratio (N20 P25/P15 N20). Reduced amplitude of N20 P25 was consistent with the high score of GOS. N20 P25 was greater than 3.7 microV in all patients who regained consciousness. Recording of cortical SEP within 48 hours after CPR was useful for the prediction of neurological outcome.

Peg3 imprinted gene on proximal chromosome 7 encodes for a zinc finger protein

Genetic and embryological studies in the mouse demonstrated functional differences between parental chromosomes during development. This is due to imprinted genes whose expression is dependent on their parental origin. In a recent systematic screen for imprinted genes, we detected Peg3 (paternally expressed gene 3). Peg3 is not expressed in parthenogenones. In interspecific hybrids, only the paternal copy of the gene is expressed in the embryos, individual tissues examined in d9.5-13.5 embryos, neonates and adults. Peg3 mRNA is a 9 kb transcript encoding an unusual zinc finger protein with eleven widely spaced C2H2 type motifs and two groups of amino acid repeats. Peg3 is expressed in early somites, branchial arches and other mesodermal tissues, as well as in the hypothalamus. Peg3 maps to the proximal region of chromosome 7. Consistent with our findings, maternal duplication of the proximal chromosome 7 causes neonatal lethality. This region is syntenic with human chromosome 19q13.1-13.3 (refs 10,11), where the genes for myotonic dystrophy and a putative tumour suppressor gene are located.

[Dynamics of photosensitizer in the cell]

1) Mono-L-aspartyl chlorin e6 is a photosensitizer with a molecular weight of 799.7 in which the double bond porphyrin ring has been reduced and an aspartic acid is attached to the propionic group at the carbon of the tetrapyrole ring via a peptide linkage. 2) The absorption spectrum of mono-L-aspartyl chlorin e6 is characterized by a Soret band at 398 nm and four Q bands located at 502, 530, 620, and 654 nm in PBS solution at pH 7.4. However, when it bound to serum albumin at ratios of more than 1:1 absorption peaks showed a red shift at 6 nm in the PBS solution. 3) Erythrocytes in the blood containing serum albumin and the same concentration of mono-L-aspartyl chlorin e6 were not lysed with the diode laser irradiation. 4) The concentration of mono-L-aspartyl chlorin e6 in mitochondria fraction of normal tissue decreased from 2 hours after intravenous injection. However, the concentration of mono-L-aspartyl chlorin e6 in mitochondria fraction of tumor increased during 4 hours after injection and then gradually decreased.

A cardiotonic steroid bufalin-like factor in human plasma induces leukemia cell differentiation

A Na+,K(+)-ATPase inhibitor, bufalin, has been shown previously to induce leukemia cell differentiation. The presence of a circulating Na+,K(+)-ATPase inhibitor has been proposed in mammals. The aim of this study was to explore an endogenous bufalin-like factor that induces leukemia cell differentiation. We found a fraction, designated as fraction A, obtained from human plasma extract that inhibits the growth of several human-derived leukemia cell lines. The effect of the fraction was retained after protease digestion or heat treatment. Murine leukemia cells and ouabain-resistant cells, which are insensitive to bufalin, appeared to be refractory to fraction A in terms of growth inhibition. Fraction A also induced functional and morphological maturation in THP-1 cells. Fraction A was recognized by anti-bufalin anti-serum and inhibited 3H-bufalin binding to K562 cells. These findings suggest that fraction A shows a similar behavior to that of bufalin on leukemia cells by inhibiting Na+,K(+)-ATPase. We propose that an endogenous Na+,K(+)-ATPase inhibitor in human plasma may play a role in cell differentiation.

Direct visualization of atherosclerosis in small coronary arteries using the epifluorescence stereoscope

OBJECTIVE

To visualize specifically at the beating heart surface atherosclerosis in small coronary arteries using the photosensitiser, mono-L-aspartyl chlorin e6 (NPe6).

METHODS

Cholesterol-fed atherosclerotic rabbits were injected intravenously with 2.0 mg/kg of NPe6. Atherosclerosis was visualized by allowing NPe6 to accumulate in atheromatous plaques, and then used as a potent fluoroprobe to illuminate atherosclerotic coronary arteries upon excitation by light. An epifluorescence stereoscope system was used to visualize atherosclerosis in small coronary arteries.

RESULTS

Although it was unable to specify the parts of the coronary arteries which had atherosclerotic changes under room light with the naked eye, several brightly illuminated branching small coronary arteries were observed clearly against the dark heart surface through the epifluorescence stereoscope, as an exciting mercury blue light beam was used to irradiate the beating heart. A fluorescence micrograph of the coronary artery, at which orange-red fluorescence was seen through the epifluorescence stereoscope, showed that the atheromatous plaques emitted orange-red fluorescence.

CONCLUSIONS

The presence and extent of small coronary atherosclerosis were demonstrated in the beating heart. Such information may help assess the clinical significance of atherosclerosis in small coronary arteries.

The effects of selective serotonin reuptake inhibitors and their metabolites on S-mephenytoin 4'-hydroxylase activity in human liver microsomes

The inhibitory effects of four selective serotonin reuptake inhibitors (SSRIs), fluoxetine, sertraline, paroxetine and citalopram, and three metabolites (norfluoxetine, demethylcitalopram and didemethylcitalopram), on S-mephenytoin 4'-hydroxylation activities in human liver microsomes were studied. The 4'-hydroxylation of S-mephenytoin, a representative substrate toward CYP2C19, was competitively inhibited by all the SSRIs and their metabolites studied. The mean Ki values of fluoxetine, norfluoxetine, sertraline, paroxetine, citalopram, demethylcitalopram and didemethylcitalopram were 5.2, 1.1, 2.0, 7.5, 87.3, 55.8 and 7.7 microM, respectively. The findings suggest that some SSRIs and their metabolites with a low Ki value (e.g., fluoxetine, norfluoxetine) may reduce the clearance of drugs metabolized by this isoform of P450, thereby resulting in a possible drug-drug interaction, when administered simultaneously. In addition, SSRIs and their metabolites examined herein may be substrates toward CYP2C19.

Induction of metallothionein synthesis by glutathione depletion after trans- and cis-stilbene oxide administration in rats

To investigate the relationship between glutathione (GSH) depletion and metallothionein (MT) synthesis, the effects of substrates and an inhibitor of GSH S-transferases on concentrations of hepatic GSH, zinc (Zn) and MT were studied in rats. Trans-stilbene oxide (TSO) is an inducer of drug metabolizing enzymes and also a substrate of GSH S-transferase, whereby it covalently reacts with and depletes GSH. The hepatic GSH level was decreased to 25% of the control 2 h after injection of TSO, and returned to the control level by 24 h. TSO significantly increased hepatic concentrations of Zn and MT in a dose-dependent manner. Two isoforms of MT (MT-I and MT-II) were increased by TSO; MT-II was the dominant form. Pretreatment with buthionine sulfoximine (BSO), an inhibitor of GSH synthesis, enhanced MT synthesis itself as well as that induced by TSO and cis-stilbene oxide (CSO). On the contrary, infection into rats of perfluorodecanoic acid (PFDA), an inhibitor of GSH S-transferase, resulted in a decrease in basal levels of Zn, and prevented the increase in MT synthesis by TSO and CSO. These results suggest that the decrease of GSH concentration in the liver which causes oxidative stress conditions may be related to MT induction.

Peg1/Mest imprinted gene on chromosome 6 identified by cDNA subtraction hybridization

Parthenogenesis in the mouse is embryonic lethal partly because of imprinted genes that are expressed only from the paternal genome. In a systematic screen using subtraction hybridization between cDNAs from normal and parthenogenetic embryos, we initially identified two apparently novel imprinted genes, Peg1 and Peg3. Peg1 (paternally expressed gene 1) or Mest, the first imprinted gene found on the mouse chromosome 6, may contribute to the lethality of parthenogenones and of embryos with a maternal duplication for the proximal chromosome 6. Peg1/Mest is widely expressed in mesodermal tissues and belongs to the alpha/beta hydrolase fold family. A similar approach with androgenones can be used to identify imprinted genes that are expressed from the maternal genome only.

[A case of Lissauer's general paresis with left hemisphere dominant brain atrophy and leuko-araiosis in the deep white matter on MRI]

A 38-year-old man presented with personality change, postural tremor of the right arm and leg, and right hemidysesthesia. MR imaging (MRI) revealed left hemisphere dominant brain atrophy and leuko-araiosis in the deep white matter. Serological test of serum and cerebrospinal fluid demonstrated high titers of antibodies to Treponema pallidum. He was diagnosed as Lissauer's general paresis based on the clinical symptoms and signs, and MRI findings. This disorder is characterized by focal cerebral atrophy, corresponding to focal neurologic signs. Neuropathological features in Lissauer's general paresis are spongiform atrophy of the cerebral cortex and demyelination of the white matter. Leuko-araiosis on MRI in our case may represent demyelination of the white matter. Although MRI findings in general paresis are usually nonspecific, this is, as far as we know the first case report of general paresis with MRI showing focal cerebral atrophy and leuko-araiosis.

Induction of hepatic microsomal P450 by 4-phenylalkylpyridines in rat: chain length-dependent and sex-related differential induction of P450s

The effects of 4-phenylalkylpyridines (chain length of 0-5, 7, 9 and 11 carbon atoms) on the induction of hepatic microsomal P450 and its multiple forms (1A1/2 (1A1, 1A2), 3A2, 2B1/2, 2C6 and 2E1) in the male and female rat have been investigated. P450 induction gradually declined with increasing chain length of the 4-phenylalkylpyridines. Immunoblot analysis revealed that three pyridine compounds having methylene units of 0, 1 and 2 only induced P4501A2, whereas those having 4, 5 or 7 methylene units only induced 1A1 in the male rat. In the female rat, however, we could not observe such a chain length-dependent differential induction of the P4501A subfamily. Induced levels of P4503A2 and 2E1 were dependent on total P450 specific content, but 2C6 was increased in a chain length-dependent manner in both sexes. These results provide new information on the differential effects of pyridine-containing compounds on P450 induction in the rat.

Bufalin induces apoptosis and influences the expression of apoptosis-related genes in human leukemia cells

A low concentration of bufalin, a component of bufadienoides in the traditional Chinese medicine chan'su, was shown previously to induce differentiation of a broad range of human leukemia cell lines. In the present study, we found that bufalin at concentrations of 10(-7) M and higher induced apoptosis in human leukemia cells, such as HL60, ML1, but not in mouse leukemia M1 cells. A mere 15 min pretreatment of HL60 cells with 10(-6) M bufalin, followed by incubation for 15 h without bufalin, caused fragmentation of DNA and a decrease in cell viability, indicating that the signal for induction of apoptosis is triggered rapidly upon treatment with bufalin. Bufalin-induced apoptosis in HL60 cells was inhibited by ZnCl2, an inhibitor of endonuclease, but not by cycloheximide, an inhibitor of protein synthesis. Northern blot analysis revealed that the levels of expression of the c-myc and bcl-2 genes in HL60 cells decreased with time after treatment with bufalin. These results suggest that bufalin induces apoptosis specifically in human leukemia cells by altering the expression of these genes involved in apoptosis.

[Somatosensory evoked potentials in a patient with a posterior postcentral gyrus lesion--generator sources of components after N20]

We studied the distribution of the median nerve somatosensory evoked potentials (SEPs) on the scalp of a 67-year-old woman with a localized old hematoma involving the posterior part of the right postcentral gyrus identified by MRI. The patient presented with an isolated loss of discriminative sensation (stereognosis, graphesthesia and position sense) of the left extremities. With respect to the SEPs on the right hemisphere, the only components remaining were the initial negativity (N20 with latency of about 20 msec) recorded in the parieto-occipital area, which exhibited polarity inversion across the central sulcus. Since area 3b is thought to be the superficial sensory cortex, the results of sensory examination in this case suggested that the hematoma was restricted to areas 1 and 2, which are thought to be the discriminative sensory cortex, and that area 3b was unaffected. We therefore conclude that the N20 on the affected hemisphere reflected the posterior pole of a horizontal dipole generated by area 3b, and that the hematoma abolished the positivity after N20, corresponding to the positive pole of a slightly delayed vertical dipole generated by the posterior part of the postcentral gyrus (areas 1 and 2).

Age-related changes in ConA-induced cytokine production by splenocytes from senescence accelerated mice SAMP8

In vitro production of interleukin-2 (IL-2), IL-4, IL-5 and interferon-gamma (IFN-gamma) by splenocytes stimulated with concanavalin A (ConA) was studied in senescence-accelerated mice (SAMP8; 2-14.5 months old) by employing AKR (2-9 months old), origin of SAM strain, as controls. Male and female SAMP8 mice showed an age-related decrease in IL-2 production from the age of 9 months and the phenomena were accompanied by an increase in IFN-gamma production with a large increment. AKR mice showed no decrease in IL-2 production even at 9 months of age, but there was an increase in IFN-gamma production showing levels lower than those in SAMP8 mice. Between IL-2 and IFN-gamma production during the ages of 2-9 months, there were negative correlations in male and female SAMP8 mice and a positive correlation in female AKR mice. The levels of IL-4 production were lower in SAMP8 than in AKR mice, although there was no difference in IL-5 production between SAMP8 and AKR mice. Male and female SAMP8 mice showed a positive correlation between IL-5 and IFN-gamma production. Only in SAMP8 females was an increase in IFN-gamma accompanied by an increase in IL-4. From these changes in the cytokine production profile was it concluded that SAMP8 mice were senescence-accelerated in immuno-responses in comparison with AKR mice and had some functional deficiency with respect to IL-4 production, a part of which resulted from over-production of IFN-gamma.

Differential effects of 3 dipyridyl isomers on hepatic microsomal cytochrome P450 and heme oxygenase in rats

We compared the effects of 3 dipyridyl isomers, 2,2'-dipyridyl, 2,4'-dipyridyl and 4,4'-dipyridyl, on hepatic microsomal heme oxygenase and drug-metabolizing enzyme activities in male rats. 2,2'-Dipyridyl increased cytochrome P450 (P450) content at lower doses, but decreased with increasing dose levels. Immunoblot analysis revealed that 2,2'-dipyridyl did not induce both P450 1A1/2 and P450 2B1/2, in contrast to 2,4'- and 4,4'-dipyridyls, both of which were inducers of either P450 1A1/2 and/or P450 2B1/2. Some drug-metabolizing enzyme activities gradually declined with the increasing dose level of 2,2'-dipyridyl. 2,2'-Dipyridyl was able to induce hepatic microsomal heme oxygenase in a dose-dependent manner, but 2,4'- and 4,4'-dipyridyls did not, even at the highest dose (0.80 mmol/kg) examined. Treatment of rats with 2,2'-dipyridyl resulted in the increase of glutathione (GSH) content in a dose-dependent manner, but not 4-substituted isomers. A time course study with 2,2'-dipyridyl revealed that it produced a significant decrease in hepatic GSH content at early time periods (2-6 h) after its administration with an inverse increase in heme oxygenase activity. The present investigation has revealed that in contrast to the induction of P450 by 4-substituted dipyridyl compounds, 2,2'-dipyridyl is a novel inducer of hepatic microsomal heme oxygenase, together with the change in hepatic GSH content. This study would provide information on the differential effects of simple dipyridyl isomers on hepatic enzymes involved in heme and drug metabolism.

[An autopsy-verified case of Creutzfeldt-Jakob disease with codon 129 polymorphism and codon 180 point mutation]

An autopsied case of Creutzfeldt-Jakob disease is reported. A 79-year-old Japanese female showed extrapyramidal sign (resting tremor, and rigidity) and dementia. She developed myoclonus and became akinetic within one year from the onset, and then died of pneumonia at age of 81. None of the members of her family had neuromuscular disorders. CT and MRI studies revealed progressive brain atrophy. Consecutive study of EEG did not reveal periodic synchronous discharges (PSD). Codon 129 polymorphism (Met/Val) and codon 180 point mutation (Val/Ile) were detected. The autopsy revealed spongiform change of cerebral cortex and negative Kuru plaques, confirming the diagnosis of Creutzfeldt-Jakob disease. Immunohistochemical study revealed weak synaptic prion staining. Western blot analysis showed positive Proteinase K resistant prion protein. Gene analysis of autopsied brain showed the same prion DNA polymorphism and mutation. The combination of codon 129 polymorphism and 180 point mutation might associate with an atypical clinical form of CJD, which shows the extrapyramidal signs at the onset, and negative PSD in EEG.

[Effect of dexamethasone on intercellular adhesion molecule-1 expression on cultured bronchial epithelial cells stimulated by inflammatory cytokines]

Bronchial asthma is characterized as a chronic inflammation of the airway that causes an infiltration of lymphocytes and eosinophils. Cell to cell interaction or cell to tissue interaction is essential for infiltration of eosinophils to underlying tissues. These phenomena are closely related to the expression of intercellular adhesion molecule-1 (ICAM-1). Inhalation of steroids, such as beclomethasone dipropionate, is commonly used to cure airway inflammation. In this study, we investigated the effect of cytokines on ICAM-1 expression on human bronchial epithelial cell lines, NCI-H292. Moreover, the effect of dexamethasone on ICAM-1 expression stimulated by IL-1 beta, TNF-alpha and IFN-gamma was observed. Treatment with IL-1 beta, TNF-alpha and IFN-gamma dose-dependently increased ICAM-1 expression on NCI-H292 cells. Inhibitory effects were exerted by dexamethasone on ICAM-1 expression in cells stimulated by IL-1 beta and IFN-gamma in a dose-dependent manner, but not in cells stimulated by TNF-alpha. These results suggest that the inhibition of ICAM-1 expression could be related to the pharmacological action of steroid drugs.

Pathogenic role of Epstein-Barr virus in human cancer

Epstein-Barr virus (EBV) is detected in several human cancers, such as Burkitt's lymphoma (BL), nasopharyngeal carcinoma, gastric cancer, and peripheral T-cell lymphoma. However, the role of EBV in the development of these cancers is still controversial. During cultivation of the EBV-positive BL line Akata, we found that EBV DNA is lost from some of the cells. Isolation of EBV-positive and -negative cell clones with the same origin made it possible to examine the effects of EBV in BL cells. The results indicate that malignant phenotypes of BL, such as the growth in low serum, anchorage-independent growth, and tumorigenicity in nude mice, are dependent on the presence of EBV genomes and underline the oncogenic function of EBV in human cancer.

Photodynamic therapy using a diode laser with mono-L-aspartyl chlorin e6 for implanted fibrosarcoma in mice

We have developed a new high-power red (664 nm) laser diode system for photodynamic therapy (PDT) with mono-L-aspartyl chlorin e6 (NPe6). Meth-A fibrosarcoma cells (1 x 10(6)) were implanted subcutaneously in the right hind leg of 4-week-old BALB/c female mice. One week later, diode laser irradiation was applied 5 h after the intravenous administration of NPe6 to each tumor-bearing mouse. In the first study, the time course of intratumor temperature increase during PDT was measured by using a 23-guage thermocouple hypodermic needle at a depth of 2 mm from the tumor surface. In the second study, 6 groups of 10 to 17 tumor-bearing mice were treated with the diode laser 5 h after intravenous administration of NPe6 at the dose of 1.25, 2.5, 5.0 or 7.5 mg/kg i.v. per mouse. Total photoirradiation ranged from 0 to 150 J/cm2 and the dose rate was adjusted to 100 mW/cm2. Percentages of cures were determined from numbers of mice apparently disease-free 50 days after treatment. The results showed that this diode laser is effective in PDT of implanted fibrosarcoma after NPe6 administration. It also confirmed that the therapeutic effects of PDT were not due to hyperthermia. Moreover, the diode laser beam was demonstrated by CCD technology to be uniform in intensity throughout the photoirradiated field.

Freeze-fracture analysis of muscle plasma membrane in Becker's muscular dystrophy

The intramembranous particle (IMP), orthogonal array (OA) and orthogonal array subunit particle (OASP) densities in skeletal muscle plasma membranes from eight patients with Becker's muscular dystrophy (BMD) were analysed by the freeze-fracture technique. The results showed almost normal IMP density with the significant decrease of OA and OASP densities in BMD. The group mean densities +/- SE of IMPs on the protoplasmic faces with and without OASPs, and on extracellular faces/microns 2 were 2137 +/- 207, 1839 +/- 68 and 895 +/- 108, respectively in controls; whereas those of BMD were 1989 +/- 259, 1837 +/- 203 and 900 +/- 239, respectively (P > 0.1 by two-tailed t-test). The group median density of OAs and their pits/microns 2 was 4.89 with mid-ranges (25-75% values of the counts) of 2.66-10.18 in controls; whereas that in BMD was 2.15 with mid-ranges of 1.14-4.31 (P < 0.01 by Wilcoxon rank-sum test). The group mean density +/- SE of OASPs in controls was 15.99 +/- 1.83; whereas that in BMD was 13.47 +/- 1.07 (P < 0.01 by two-tailed t-test). However, the diminution of OA and OASP densities in BMD muscle plasma membranes was not as severe as in Duchenne's muscular dystrophy. There was a relationship between OA density and clinical severity in BMD patients; the decrease of OA density in a severe BMD patient was more marked than that in mildly affected BMD patients. Therefore, it seems that marked depletion of OA density may lead to the severe disability in muscular dystrophies.

Isolation of Epstein-Barr virus (EBV)-negative cell clones from the EBV-positive Burkitt's lymphoma (BL) line Akata: malignant phenotypes of BL cells are dependent on EBV

During cultivation of the Epstein-Barr virus (EBV)-positive Burkitt's lymphoma (BL) line Akata, it was noted that EBV DNA is lost from some of the cells. Isolation of EBV-positive and EBV-negative clones with the same origin made it possible to examine the effects of EBV in BL cells. The results indicate that malignant phenotypes of BL, such as growth in low serum, anchorage-independent growth in soft agar, and tumorigenicity in nude mice, are dependent on the presence of EBV genomes and underline the oncogenic function of EBV in human cancer.

Photodynamic effect using a diode laser with mono-l-aspartyl chlorin e6 (NPe6) for implanted mouse tumor

A new red diode laser has been developed that is suited for use in photodynamic therapy (PDT). The new laser can be used with NPe6, a photosensitizer that does not prolong normal skin sensitiveness. This study examined the effectiveness of PDT using the diode laser and compound for treatment of fibrosarcoma implanted in BALB/c mice.

Involvement of Na+,K(+)-ATPase inhibition in K562 cell differentiation induced by bufalin

Human leukemia K562 cell differentiation induction by naturally occurring bufadienolides purified from the Chinese drug Senso and synthetic bufalin derivatives was examined by a nitro blue tetrazolium reduction assay. Bufalin showed the strongest activity among all the bufadienolides tested in this study. The degree of the induction of nitro blue diformazan positive cells by the bufadienolides correlated well with their inhibitory activities against Na+,K(+)-ATPase prepared from K562 cells in vitro. N+,K(+)-ATPases from a variant K562 clone (ouabain resistant, OuaR) and murine leukemia cell line M1-T22, which were insensitive to the bufadienolides in terms of growth inhibition and cell differentiation, appeared to be refractory to bufalin in vitro. A binding study of 3H-bufalin and 3H-ouabain revealed that saturated levels of both ligands associated with K562 cells were virtually similar; however, affinity of 3H-bufalin was considerably higher than 3H-ouabain. The saturated level of 3H-bufalin observed in the OuaR cells was approximately half of that observed in K562 cells without a change in its affinity. Association of 3H-bufalin with K562 cells was completely blocked by pretreatment of the cells with cold ouabain at concentrations saturating the binding sites. These results suggest that bufalin acts on the cells by binding to sites on the cell membrane which also bind ouabain. It is thus proposed that N+,K(+)-ATPase inhibition is closely related to the initiation process in the induction of K562 cell differentiation induced by bufalin.

Development and preliminary application of a high-performance liquid chromatographic assay for omeprazole metabolism in human liver microsomes

A high-performance liquid chromatography assay was developed to measure the enzymatic activities of the 5-hydroxylation and sulphoxidation of omeprazole, a proton pump inhibitor, in human liver microsomes. The preliminary study was also undertaken to assess the assay's applicability for the enzyme kinetic analysis of omeprazole metabolism by human liver microsomes. The recovery of 5-hydroxyomeprazole, omeprazole sulphone and phenacetin (internal standard) after the precipitation of microsomal protein by acetonitrile was nearly complete. The intra-assay relative standard deviations (n = 6) were 8.2 and 12.8% for quantitation of the 5-hydroxylation and sulphoxidation activities of omeprazole, respectively. Eadie-Hofstee plots for the formation of 5-hydroxyomeprazole and omeprazole sulphone gave a biphasic relationship for all the microsomal samples studied (n = 6). The respective mean (+/- SD) high- and low-affinity component kinetic parameters for the 5-hydroxylation and sulphoxidation of omeprazole estimated by a two-enzyme kinetic analysis were: Km1 = 6.3 +/- 1.7 and 10.4 +/- 6.3 microM, Km2 = 183.2 +/- 180.4 and 671.2 +/- 639.4 microM, Vmax1 = 109.8 +/- 75.4 and 77.5 +/- 46.1 pmol mg-1 min-1, and Vmax2 = 163.3 +/- 94.1 and 318.3 +/- 163.3 pmol mg-1 min-1. The results suggest that the assay is reproducible, accurate and applicable for studying the metabolism of omeprazole in human liver microsomes.

Selective inhibitory effect of bufalin on growth of human tumor cells in vitro: association with the induction of apoptosis in leukemia HL-60 cells

We found that bufalin, an active principle of the Chinese medicine chan'su, has selective inhibitory effects on the growth of various human cancer cells. In order to examine whether the growth-inhibitory effect of bufalin on human cancer cells is associated with apoptosis, human leukemia cells were treated with bufalin. HL-60, ML1, and U937 leukemia cells treated with bufalin at 10(-8) M and above had condensed and fragmented nuclei. Flow cytometric analysis of these cells treated with bufalin showed fragmented DNA smaller than that of the G1 phase. DNA of HL-60 cells treated with bufalin showed a ladder pattern characteristic of apoptosis, as analyzed by agarose gel electrophoretic analysis. DNA synthesis and topoisomerase II activity of HL-60 cells were markedly inhibited as the concentration of bufalin was increased. The concentration needed for inducing apoptosis of HL-60 cells was 10(-8) M, which is comparable to that of camptothecin, but lower than those of other antitumor drugs such as cisplatin, VP16 and all-trans retinoic acid. Apoptosis was not observed when human mononuclear and polymorphonuclear cells were treated with 10(-6) M bufalin for 24 h. These results indicate the association of the growth-inhibitory effect of bufalin with the induction of apoptosis, at least in HL-60 cells, and suggest the usefulness of bufalin for differentiation-apoptosis-inducing therapy for cancer.

Bradykinin induces generation of reactive oxygen species in bovine aortic endothelial cells

We investigated the effects of bradykinin on intracellular oxidative stress in bovine aortic endothelial cells using a hydroperoxide-sensitive fluorescent dye, 2',7'-dichlorofluorescein (DCFH), and a laser scanning confocal microscope. Bradykinin induced an immediate increase in intracellular Ca2+ concentration, and stimulated the oxidation of DCFH in cultured endothelial cells. This bradykinin-induced oxidation of DCFH was inhibited by pretreatment with N-(2-mercaptopropionyl)-glycine (MPG) and 1,3-dimethyl-thiourea (DMTU), scavengers of hydroxyl radical, and the removal of extracellular Ca2+ but was unaffected by NG-nitro-L-arginine or NG-monomethyl-L-arginine, both inhibitors of nitric oxide (NO) synthase. On the other hand, pretreatment with indomethacin and aspirin, inhibitors of cyclooxygenase, inhibited bradykinin-induced oxidation of DCFH. These findings suggest that bradykinin increases intracellular Ca2+ and stimulates the generation of hydroxyl radical-like reactive oxygen species (scavenged by MPG or DMTU) via the cyclooxygenase pathway but not via the reaction of NO and superoxide anion.

Involvement of testosterone in the induction of hepatic microsomal cytochrome P-450 2B1/2 (P-450 2B1/2) by 1-benzylimidazole in male and female rats: sex-differentiated induction of P-450 2B1/2 species

We examined the effect of 1-benzylimidazole on the induction of cytochrome P-450 1A1/2 (P-450 1A1/2) and cytochrome P-450 2B1/2 (P-450 2B1/2) in normal, castrated, ovariectomized and hypophysectomized male rats, and in castrated rats treated with testosterone. 1-Benzylimidazole markedly increased P-450 content in male and female rats. Parallel to the dose-dependent increase in P-450 content, 1-benzylimidazole produced a significant increase in P-450 2B1/2 in male rats, but not in female rats. 1-Benzylimidazole failed to induce P-450 2B1/2 in castrated male and ovariectomized female rats. Treatment of castrated male rats with testosterone restored the induction of P-450 2B1/2 by 1-benzylimidazole. Treatment of ovariectomized female rats with 1-benzylimidazole or phenobarbital led to the increase in P-450 content, accompanying by the induction of P-450 2B1/2 by the latter treatment, but not the former. In hypophysectomized male rats, 1-benzylimidazole was able to induce P-450 2B1/2 in contrast to castrated male rats. Neonatal male and female rats responded well to the induction of P-450 2B1/2 by 1-benzylimidazole. The present findings suggest that P-450 2B1/2 induction by 1-benzylimidazole would be coupled with circulating testosterone regulated by hypophysis-testis axis. 1-Benzylimidazole produced sex-differentiated induction of P-450 2B1/2 in pubertal rats, but not in neonatal animals. The present findings would be provide information on a unique effect of 1-benzylimidazole on P-450 2B1/2 induction in rats.

[Cerebellar ataxia with hypogonadotropic hypogonadism and mental disturbance]

Cerebellar ataxia with hypogonadotropic hypogonadism is a rare condition. Both hypothalamic LHRH and pituitary gonadotropin deficiency may appear with cerebellar ataxia. In this report, a 19-year-old man who presented with progressive cerebellar ataxia and mental disturbance was found to have low plasma gonadotropin levels. No rise in gonadotropin was demonstrated after repeated stimulation with LHRH. Our findings suggested that the cause of hypogonadism was pituitary gonadotropin deficiency, or both hypothalamic and pituitary dysfunction. The endocrinological data and clinical features of our patient and all other reported cases suggest that the age of onset of the illness is related to the type of endocrinological abnormality: young-onset patients may have endocrine disturbances involving both the hypothalamus and the pituitary gland, which may be affected secondary to the hypothalamic disturbance, whereas adult-onset patients may show only hypothalamic disturbance.