During 2-aminobenzamide (2-AB)-labeling of sialo-oligosaccharides the authors encountered a significant loss of sialic acids under the reported conditions, at 65°C for 2 h. By examination of the relationship between labeling temperature and recovery of tetra-sialylated oligosaccharides, 2-AB-labeling at 37°C for 16 h resulted in a maximum yield with practically no loss of sialic asid.Under the newly optimized conditions, the reproducibility of 2-AB-labeling was examined in triplicate with three lots of recombinant human erythropoietin (r-HuEPO). The present conditions gave analytical date comparable to those obtained by the established NaB[3H]4 labeling procedure. The modified method has been applied to oligosaccharide structural analysis of sialoglycoprotein therapeutics.
A convenient method was developed to select mobile phase to separate drugs commonly used in clinical therapy, using high-performance liquid chromatography (HPLC). The separation condetions determined by this method were similar for each compound. Two kinds of mobile phase, a mixture of acetonitrile-phosphate buffers, pH 4.2 and 2.5, was used and the composition of mobile phase used for a drug in HPLC analysis was systematically determined as follows : (1) the retention time of a drug was measured under the gradient condition, (2) this retention time value was applied to the regression equation which was determined from the retention time values of p-hydroxybenzoate derivatives under the gradient condition and the concentration of acetonitrile in mobile phase, giving about 5 min of retention time, (3) percentage of acetonitrile in the isocratic condition was calculated from this regression equation and a target drug was eluted with the mobile phase consisting of the calculated concentration of acetonitrile. According to the proposed method, the composition of mobile phase, with which retention time value was between 4 to 8 min in the isocratic condition, was examined for 75 drugs clinically used. Seventy-two of the 75 drugs were analyzed well in the mobile phase, their composition was calculated by the regression equation, and the peak shape of each compound was observed to be sharp. Using this method, the time required for not only the setting of HPLC conditions but also analysis will be shortened.
To investigate the individual role of MerT and MerP encoded by Pseudomonas K-62 pMR26 in the transport of phenylmercury, a series of mutants with a specific point mutation in merT and/or genetic deletion in merP were constructed and transformed into Escherichia coil XL-1-Blue. Transport of phenylmercury across the cytoplasmic membrane of E. coli mediated by MerT and MerP was inhibited by NaCN and by cold temperatures. Deletion of merP reduced, but did not completely abolish the C6H5Hg+-hyperuptake and -hypersensitive phenotypes suggesting that transport of phenylmercury into the cytoplasm of E. coli is still occurring. Mutations of the vicinal cysteine residues (Cys24 and Cys25) in the first transmembrane region of MerT to serine caused complete loss of Hg2+-hyperuptake and -hypersensitivity, whereas the mutations did not affect the C6H5Hg+-hyperuptake and -hypersensitive phenotypes. In addition, no additive effect on the C6H5Hg+-hyperuptake and -hypersensitive phenotypes was found, when mutations of the two cysteines in MerT to serine were further introduced in the merP-deleted mutants. These results clearly demonstrated that the vicinal cysteine residues of MerT are not involved in the transport of C6H5Hg+, but indeed are involved in the transport of Hg2+ as previously reported.
ICR/f mutation in rat, an inherited disorder, is characterized by the development of cataracts. In this study, we analuzed and compared the crystallins in normal and cataractous rat lenses using gel filtration and two-dimensional gel electrophoresis, and determined the transglutaminase activities and Ca2+ content in the mutant and normal lenses. The Ca2+ content about 10-fold and the activity of transglutaminase was about 1.8-fold higher in the cataractous lenses than in the normal lenses. Analysis of the cataractous lens proteins showed a remarkable decrease in γ-, βB1-, βA3-, and βA4-crystallin content, accompanied with some increase in α-crystallin (or its aggregate). Higher molecular weight proteins were also observed in the cateractous lenses, with molecular masses which correspond to those fo cross-linked dimera (43 to 55 kDa) of β-crystallins. We consider that the mutation accelerates the aggregation of the crystallins, which is assosiated with their cross-linking by transglutaminase.
Fibroblast-populated collagen gel cultures have been used as a dermal model of wound contraction and granulation in the wound healing process and as an in vitro model of dermal tissue. We evaluated the effects of various natural product extracts on collagen gel contraction-promoting activity and mechanical properties (relaxation time) using this model, and observed that some natural product extracts, such as Hibamata extract(from Fucus vesiculosus) promoted gel contraction and increased the relaxation time of the gels.In addition, we investigated the mechanism of the promotion of the gel contraction, noting increased expression of integrin α2 and β1 subunit molecules on the surface of the fibroblasts, suggesting that some extracts, such as Hibamata extract, promote gel contraction by increasing the expression of integrin molecules on the fibroblasts surface. For other types of natural product extracts, other mechanisms of the gel contraction-promoting activity, which were independent of an increase of integrins, were suggested.Although the mechanisms of promotion of gel contraction by these extracts are still unclear, it is at least clear that, more than one mechanism appears to be present. Therefore, more effective drug regimens for improving dermal tissues and wound healing may be achieved by combining drugs which increase integrin molecules and drugs with other mechanisms of action.
Ginsenosides are deglycosylated by intestinal bacteria to active forms after oral administration. The present study demonstrated the pharmacobynamics of 20-O-β-D-glucopyranosyl-20(S)-protopanaxadiol (M1), an intestinal bacterial metabokite of ginsenosides, and the in vitro and in vivo antitumor activities of M1-metabolites in comparison with M1 using C57BL/6 mice and Wistar rats. M1 wsa selectively accumulated into the liver soon after its intravenous administration to mice, and mostly excreted as bile; however, some M1 was transformed to fatty acid ester (EM1) in the liver. EM1 was isolated from rats in a recovery dose of approximately 24 mol%. Structural analysis indicated that EM1 comprised a family of fatty acid mono-esters of M1. Because EM1 was not excreted as bile as M1 was, it was accumulated in the liver longer than M1. Although the cytotoxicity of M1 against B16-F10 melanoma cells was attenuated by fatty acid esterification, EM1 inhibited tumor growth more than M1 in vivo. These results suggest that the fatty acid M1 esters may be the real active principles of ginsenosides in the body.
The actions and interactions of heavy metals on certain organ function have been of concern, since occupational exposure to certain metals results in impairment of functions, Studies were carried out to determine the effects of zinc (Zn) and mersury (Hg) on murine liver. CD-1 male mice were administered 4 ppm HgCl2, 800 ppm ZnCl2, 4 ppm HgCl2+800 ppm ZnCl2 or deionized water in their drinking water for 12 weeks. Histological evaluation of the liver confirmed the toxic effects of Hg, as well as the normal morphology of the Zn-exposed animals. A combined treatment of both metals resulted in protection of the Hg-induced liver damage by Zn. The results of this experiment indicate that Hg has a toxic effect on liver, while Zn has a protective action against such toxic effects.
The antioxidant action of Artemisia camprestris was examined in vitro and in vivo. A water extract of A. campestris showed a strong scavenging action of 1, 1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl and superoxide anion radicals. When the extract was given intraperitoneally to mice prior to carbon tetrachloride (CCl4) treatment, CCl4-induced liver toxicity, as seen by an elevation of serum aspartate aminotransferase and alanine aminotransferase activities, was significantly reduced. Depression of the elevation of serum enzyme levels after CCl4-treatment was also observed by oral administration of the extract. In that case, CCl4-derived lipid peroxidation in the liver was decreased by the extrac treatment. These results suggest that the extract of A. comprestris scavenges radicals formed by CCl4 treatment resulting in protection against CCl4-induced liver toxicity.
To establish an easy and rapid method for measuring the adhesive strength of fibrin glue and to clarify the factor(s) most affecting the strength, a study was made on the effect of the concentration of plasma components on the strength of cryoprecipitate (Cryo) prepared from a subject's own autologous plasma to be used as fibrin glue. The adhesive strength of the Cryo was measured with various supporting materials instead of animal skin using a tester of tension and compression. The results were as follows : (1) the strength of Cryo applied to ground flat glass (4cm2) was significantly greater than that applied to clear glass, clear plastic, or smooth and flat wood chips; (2) the adhesive strength of Cryo depended on the concentration of thrombin with the optimal concentration being 50 units/ml; (3) the concentration of CaCl2 did not affect the adhesive strength of Cryo; (4) the adhesive reaction was dependent on the temperature and the adhesive strength more quickly reached a steady state at 37°C than at lower temperature; (5) the adhesive strength was correlated well with the total concentration of fibrinogen and fibronectin. These results indicate that the adhesive strengh of Cryo can be easily and quicky evaluated using a tester and ground glass with thrombin at 50 units/ml, and that the adhesive strength of Cryo can be predicted from the total concentration of fibrinogen and fibronoctin.
The antitumor effects against solid tumors, such as Meth A saroma, MH-134 hepatoma and colon 26 adenocarcinoma, were examined after intratumoral administration of liposomes and Tumor Necrosis Factor (TNF)solution. The antitumor effects of liposomes against solid tumors were superior to those of TNF solution. In particular, the antitumor effect of positively charged (decyl amine) liposomes was superior to that of negatively charged liposomes and TNF solution. Futher, positively charged liposomes contaning a higher dose of TNF than the solution could be administered without killing the mice, because of reduced side-effects. After intratumoral (Meth A sarcoma) administration, the TNF plasma concentration was determined in order to estimate the systemic side-effects of TNF. The area under curve (AUC) after administration of positively charged liposomes containing 6 times dose of TNF was about 1/30 the AUC after the administration of TNF solution. After administration of positively charged liposomes, TNF was mainly retained locally. Positively charged liposomes exhibited a stronger antitumor effect than the solution and had a lower AUC (about 1/180) than the solution. Consequenty, some solid tumors could be complerely cured by positively charged liposomes, because of their increased antitumor effect and reduced toxicity.
The potential of liposomes as an intranasal dosage formulation for topical application was investigated in rats. When 5(6)-carboxyfluorescein (CF), a model absorbable drug, dissolved in phoshate-buffered saline (PBS)was administered intranasally, CF was rapidly absorbed into the systemic circulation and no adhesion of CF to the nasal mucosa was observed. The fraction of CF absorbed from the nasal mucosa reached about 48% 1 h after administration. On the other hand, only 3% of the dose was absorbed when CF was encapsulated in liposomes consisting of dipalmitoylphosphatidylcholine and cholesterol (DPPC-liposomes). In addition, the amount of CF adhering to the nasal mucosa after administration as DDPC-liposomes was 20- to 28-fold greater than that in PBS solution. In particular, positively charged liposomes markedly enhanced the adhesion of CF to the nasal mucosa. Differences in the lipid composition of liposomes did not affect the absorption of CF. However, the ability of liposomes to adhere to the nasal mucosa was consistent with the fluidity of the liposomal membrane. Furthermore, the action of liposomes on the anti-histaminic effect of diphenhydramine hydrochloride (DH) was studied in rats by measuring the amount of protein leaking into the nasal cavity under quasi-allergic conditions. The anti-histaminic effect of DH was strong but of short-duration when DH was administered as a PBS solution. However, liposomes prolonged the anti-histaminic effect of DH, suggesting that liposomes may adhere to the nasal mucosa and release DH slowly. In conclusion. liposomes suppress drug absorption into the systemic circulation and concurrently increase drug retention in the nasal cavity.
We previously demonstrated that topical treatment with disulfiram (DSF) prevented the development of cataracts in sodium selenite-injected rat pups. In biological systems, DSF is rapidly reduced to diethyldithiocarbamate (DDC), a potent antioxidant. In this study, we investigated the effect of altering the lipid composition of liposomes containing DSF on the transcorneal transit of DDC. Liposomes containing DSF were prepared with various molar ratios of dimyristoylphosphatidylcholine (DMPC), dipalmitoylphosphatidylcholine (DPPC) and cetylpyridinum chloride (CPC) by reverse-phase evaporation. Liposomes with a DMPC to DPPC molar ratio of 5 : 5, examined by differential scanning calorimetry, had the highest enthalpy of transition and the presence of one molar ratio of CPC further enhanced the enthalpy value. The addition of bovine serum albumin or a homogenate of rabbit cornea to the incunation buffer resulted in the release of DDC, but not DSF from the liposomes. The amount of DDC present in the aqueous humor of rabbit eyes following topical administration increased with increase in DMPC to DPPC ratios and was also enhanced by the addition of CPC to the liposomes. The results of this study suggest that liposome formulations are effective for transorneal drug delivery of anticataract agents such as DSF. DSF in liposomes consisting of DMPC, DPPC, and CPC with a molar ratio of 8 : 2 : 1 may be a potential drug formulation for the prevention and/or treatment of cataracts.
The contributions of incomplete absorption and a first-pass effect to the low bioavailability (BA) of methotrexate (MTX) were evaluated pharmacokinetically in rats and monkeys which respectively have a lower and higher aldehyde oxidase (AO) activity than humans. Plasma concentration profiles of MTX in rats showed linear and nonlinear pharmacokinetics respectively after intravenous (i.v.) and oral dosing of 0.1, 0.5 or 2.5 mg/kg MTX. In rats, most of the dose was excreted as the parent compound into bile and urine after i.v. dosing of 0.5 mg/kg MTX, while the radioactivity was largely eliminated in expired air after oral dosing of 0.5 mg/kg 14C-MTX. Elimination in expired air fell markedly following antibiotics treatment. 7-Hydroxymethotrexate (7-OH-MTX), formed from MTX by AO, was detected in monkey plasma after i.v. and oral dosing of 0.5 mg/kg MTX, but not in rat plasma. The ratio of the cumulative urinary excretion of 7-OH-MTX to MTX in monkeys was higher after oral dosing than after i.v. dosing. The low BA in rats (10% at 0.5 mg/kg) was shown to be mainly due to incomplete absorption, including limeted absorption and degradation to 2, 4-diamino-N10-methylpteroic acid (DAMPA) and glutamic acid (Glu) by the carboxypeptidase of intestinal bacteria. The low BA in monkeys (5% at 0.5 mg/kg) was shown to be mainly due to the extensive first-pass effect, including metabolism to 7-OH-MTX.
The purpose of this study was to evaluate the influence of caffeine and theophylline on the development of dental caries in rats. Six Wistar dams (spf), mutans streptococci free, were obtained, with each six male pups. The dams were infected by Streptococcus sobrinus 6715 and into divided three groups which received during the lactating period : (1) diet 2000; (2) diet 2000 plus caffeine (2 mg/100 g) and (3) diet 2000 plus theophyline(0.57 mg/100 g). After weaning. the pups were infected by S. sobrinus, placed in a Konig-Hofer programmed feeder machine, and received 17 meals daily at hourly intervals, for five weeks. During this time the pups were fed with the same diet that their dams were. The percentage of S. sobrinus relative to total flora was significantly higher in the theophylline group. The results for slight (Ds) and moderate (Dm) dentine lesions, for smooth-surface and sulcal scores were statistically higher for the theophylline group than the other groups. Salivary assays did not demonstrate significant inorganic alterations in salivary composition. Caffeine and theophylline groups showed the highest ulcer score. It is concluded that caffeine does not affect the cariogenic potential of the diet, however theophylline can increase the development of dental caries, and this effect may be related to organic alterations of salivary composition.
The antitumor effects of cis[((1R, 2R)-1, 2-cyclohexanediamine-N.N')bis(myristato)] platinum(II) (SM-11355)were evaluated in a rat hepatic tumor model, and were compared with those of cisplatin (CDDP). A novel slowlygrowing rat hepatic tumor model was established by the successive transplantation or rat AH109A Tumor into the ilver. The drugs, which were suspended in Lipiodol, were administered into the proper hepatic artery of tumor-bearing rats. Tumor growth was suppressed in the group that received SM-11355 suspended in Lipiodol(SM-11355/Lipiodol). Mean tumor growth rates in the groups administered 20 μl of Lipiodol containing 0, 0.02, 0.04, 0.1, 0.2, or 0.4 mg of SM-11355 were 244, 86, 110, 81, 51, and 40%, respectively. 1 week after treatiment. Those in the groups administered 20 μl of Lipiodol containing 0.1, 0.2, or 0.4 mg of CDDP were 240, 110, and 45%, respectively. In the groups administered 0.2 and 0.4 mg of SM-11355 or 0.4 mg of CDDP, massive necrosis was observed in the tumor tissue 1 week after drug administration, and the tumors disappeared 4 weeks after drug administration. Serum glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase(GPT) levels were measured as markers of liver damage one day after the drug was administered into the hepatic artery of rats. The minimum toxic dose, which raised serum GOT and GPT levels significantly compared with Lipiodol alone, was 0.2 mg for SM-11355/Lipiodol and 0.1 mg for CDDP/Lipiodol, respectively. The results demonstrated that SM-11355/Lipiodol exerted antitumor activity at a dose that showed no hepatic toxicity in the rat model, but CDDP/Lipiodol did not.
Basic flbroblast growth factor (bFGF) has been shown to stimulate proliferation and defferentiation of neural stem cells through regulation of gene expressions. To clarify the roles of bFGF during early neurogenesis, we performed a series of differential display with mRNAs from an immortalized neural stem cell line treated with bFGF for different periods. We isolated ten independent cDNAs whose mRNA levels were regulated by bFGF. Some of these cDNA were identical to known genes, including calmodulin and thrombospondin 1, while other were unknouwn genes. One of these unknown genes up-regulated by bFGF (clone 2C) was specifically expressed in the brain among various rat tissues. It is expected that further analysis of clone 2C will reveal important roles of bFGF in the regulation of brain development.
We examined the effects of Dai-kenchu-to (DKCT) on the levels of vasoactive intestinal peptide (VIP) and 5-hydroxytryptamine (serotonin; 5-HT) in plasma taken from 6 healthy subjects. A single oral administration of 7.5 g DKCT caused significant increases in plasma VIP at 30, 60 to 90 and 120 min (3.5-5.5 pg/ml), compared with the response in a placebo group (about 1.0 pg/ml). DKCT also caused significant increases in plasma 5-HT at 30 (121.8±7.3 ng/ml) and 60 (156.5±8.0 ng/ml) min, compared with the response in the placebo group (about 101 ng/ml). These results indicate that the stimulatory effect of DKCT on VIP-immunoreactive substance (VIP-IS) secretion is due, at least in part, to increased 5-HT levels in the abdomen. As a consequence, increased VIP-IS may improve feelings of coldness in the abdomen.
The cytotoxicities of pyridino[2, 3-f]indole-4, 9-dione derivatives were examined against human lung tumor cell lines (A 549), human ovarian tumor cell lines (SK-OV-3), human melanoma tumor cell lines (SK-MEL-2), human CNS tumor cell lines (XF 498) and numan colon tumor cell lines (HCT 15) in vitro using a Sulforhodamine B assay. 3-Ethoxycarbonyl-1-(2-methoxyethyl)-2-methyl-1H-pyridino[2, 3-f]indole-4, 9-dione (5) showed excellent cytotoxicity against XF 498 and HCT 15. The ED50 values of 5 were 0.006 μg/ml against XF 498 and 0.073 μg/ml against HCT 15, while those of doxorubicin were 0.012 and 0.264 μg/ml, respectively. 1-Benzyl-3-ethoxycarbonyl-2-methyl-1H-pyridino[2, 3-f]indole-4, 9-dione (7) (ED50 value 0.065 μg/ml) was also significanty more cytotoxic against HCT 15 compared with doxorubicin.
The inhibitory effect of some traditional herbal medicines on the infectivity of rotavirus, which predominanthy occurs in sporadic diarrhea in infants and young children, was investigated. Among the 34 kinds of herbal medicines tested, the fruit of Citrus aurantium had the most potent inhibitory activity on rotavirus infection. The active components of the fruit of Citrus aurantium were neohesperidin and hesperidin. Their 50% inhibitory concentrations were 25 and 10 μM, respectively.
Perilla citriodora NAKAI, the wild species of Perilla, was collected from Taiwan and its essential oil analyzed. Gc-MS analysis of its oil showed that it has a novel composition of limonene (23.5%) and elemicin (17.8%). In Japanese Perilla, A monoterpene (limonene) and a phenylpropanoid (elemicin) have not been detected in the same plant. To compare the sequence similarity of a secondary metabolic enzyme between P. frutescens and P. citriodora, the nucleic acid sepuence of the limonene synthase in this P. citriodora was analyzed using the reverse transcript-polymerase chain reaction (RT-PCR) method. Primers for PCR were designed by employing the known sequence of the limonene synthase cloned from P. frutescens. It was found that the limonene synthase in P. citriodora and that in P. frutescens share a high sequence identity, probably indicating that both enzymes evolved from a common ancestor.
Since some Solanum-genus plants have traditionally been used for anti-cancer and anti-herpes agents from olden times, we examined anti-herpes simplex virus type 1 (HSV-1) activity of typical steroidal glycosides with the frameworks of spirostane (including nuatigenin glycoside), furostane, solasodane, tomatidane and ergostane(including dimer) obtained from solanum plants. Among these steroidal glycosides, the spirostanol glycosides were most effective. An inclination was observed for the potency of activity to decrease in the order of spirostane, tomatidane, ergostane, solasodane, nuatigenin type, dimer of ergostane and furostane. It was also suggested that the activity depends on the kind of oligosacchride moiety.
This study was carried out to elucidate the antiinflammatory active principles obtained from 70% methanol extract of the dried fruit of Forsythia suspensa VAHL (F. suspensa). The methanol extract was then partitioned between n-hexane and water, and then the n-hexane fraction was evaporated to dryness under vacuum The n-hexane fraction was chromatographed (Frs. I-V), Fr. IV was rechromatographed (Frs. VI-VIII), and then Fr. VII was rechtomatographed (Frs. IX-XI) by silica gel column chromatography. The antiinflammatory activity of these fractions was investigated on acetic acid-induced vascular permeability in rats. The n-hexane fraction showed an antiinflammatory effect and these activities shifted successively to Fr. IV, Fr. VII and Fr. X. The chemical structure of the active principle obtained from Fr. X was identified as 3β-acetoxy-20, 25-epoxydammarane-24-ol. These results suggest that the antiinflammatory and an analgesic effect of 70% methanol extract of F. suspensa may be the result of the compound that it contains.
Quantification of human immunodeficiency virus type 1 (HIV-1) genomic RNA levels below the detection limit (400 copies/ml) of commercially available quantification kits is possible by increasing the amount of serum samples using competitive PCR conditions. We evaluated disease prognosis in patiets without symptoms for a long period after infection (long-term non-progressor) and patients in whom the virus was controlled to a low level by administration of anti-HIV drugs. For 102 of the 414 serum samples stored at -80°C which showed HIV-1 RNA below 400 copies/ml by competitive PCR using 100 to 200 μl sera, an increase in the sample volume to 500-2000 μl, extraction of HIV-1 RNA, and quantitative detection by competitive PCR was performed. Follow-up quantification of serum HIV-1 RNA from 4 patients indicate that this method is useful in assessing prognosis in the early stage of the disease in patients without symptoms for a long period after infection (long-term non-progressor) and patients in whom the virus in the serum was controlled by administration of anti-HIV drugs to below the detection limit of commercially available quantification kits. Quantification of low level serum HIV-1 RNA was also considered useful as a parameter of treatment.
To clarify the release properties of anti-cancer drugs from fibrin glue, a study was performed using several anti-cancer drugs with remarkably different physical properties. Consentrated fibrinogen, fibronectin, and coagulation factor XIII were prepared from healthy human plasma according to the cryoprecipitate method. Fibrin glue containing anti-cancer drugs was prepared as follows; the cryoprecipitate was mixed with each anti-cancer drug and aprotinin, then thrombin was added. These glues were incubated in PBS containing plasminogen and urokinase at 37°C for seven days, and the medium was then sampled several times after centrifugation. The drug concentration in each sample was measured using HPLC. Fibrin glue without aprotinin was quickly hemolyzed and disappeared after 2-4 h. That with aprotinin was only slighty homolyzed and more than half remained after 7 days. Mitomycin C and fluorouracil were quickly released from the glue regardless of the presence or absence of aprotinin. However, enocitabine was gradually released from glue with aprotinin although quickly released from that without. The rate of release of each drug from the glue with aprotinin correlated well with its hydrophobicity. Thus, to establish a sustained release system using fibrin glue, one should use the more lipophilic anti-cancer drugs and a fibrinolytic enzyme inhibitor.
Semi-synthetic tetrahydroisoquinoline derivatives prepared from natural alkaloids, possess Ca2+ antagonistic properties. These derivatives significantly blocked KCl-stimulated Ca2+ uptake (In chick and rat crude nerve ending) which can be partially inhibited by the selective N-type Ca2+ channel blocker ω-conotoxin GVIA or the selective P-type Ca2+ channel blocker ω-agatoxin IVA. Moreover, PX42 (10 μM; for the tetrahydroisoquinoline compounds in this study) could inhibit the activity of calmodulin-dependent phosphodiesterase and block veratridine-induced (or tetrodotoxin-sensitive) Na+ uptake. The possible mechanism(s) of non-selective inhibition of ion channels of PX42 is discussed.