Drug interaction effects on antitumour drugs (X): exacerbation of cisplatin lethality by bacterial lipopolysaccharide in mice

To determine whether bacterial endotoxin (lipopolysaccharide, LPS from Escherichia coli) could modulate the lethality of cisplatin (CDDP) in mice, animals were treated with LPS (1 mg/kg, intraperitoneally) 24 hr and 1 hr before administration of cisplatin. A 1.6-fold increase in 8-day cumulative mortality was observed in LPS-treated mice compared to the mortality of those injected with saline before CDDP administration. The duration of previous exposure time to LPS appeared to be an important determinant of the potentiating effect, as many more mice died after 24 hr pretreatment than after 1 hr. Because renal toxicity remains a serious limitation to the effective use of CDDP, we determined whether LPS could also enhance CDDP-induced renal injury. CDDP markedly induces an increase in blood urea nitrogen (BUN) levels in LPS-treated mice. Treatment with LPS did not affect urinary excretion or renal tissue levels of total platinum, or the plasma pharmacokinetics of free and total platinum. Despite the potentiating effect of LPS on CDDP-induced lethality, it appeared that LPS can provide some enhancement of kidney function, because pretreatment of LPS enhanced an increase in BUN values.

Comparative base specificity, stability, and lectin activity of two lectins from eggs of Rana catesbeiana and R. japonica and liver ribonuclease from R. catesbeiana

Two lectins with RNase activity obtained from eggs of Rana catesbeiana and R. japonica and RNase obtained from R. catesbeiana liver show 65-83% protein homology. The base specificity of these frog proteins was studied with 8 dinucleoside phosphates as substrates and 8 nucleotides as inhibitors. The base specificities of the B1 and B2 sites of these proteins are U greater than C and G greater than U greater than A, C, respectively. The three frog proteins are more resistant than RNase A to heat treatment, guanidine-HCl and pH-induced denaturation; i.e., they retain their native conformation up to at least 70 degrees C at pH 7.5. Differences in stability and base specificity among RNase A and the three frog proteins are discussed in relation to the primary structures. Although the two lectins agglutinate tumor cells (e.g., Ehrlich, S-180 and AH109A ascites carcinoma cells), the liver RNase has no such activity. Agglutination of AH109A cells by the two lectins is inhibited by nucleotides. Our results indicate that the agglutination sites are not identical with, but are related to, the active sites of the three frog proteins.

Preventive effects of a Chinese herb medicine (sho-saiko-to) against lethality after recombinant human tumor necrosis factor administration in mice

We observed the effects of a chinese herb medicine Sho-saiko-to on the lethal and antitumor activities of recombinant human tumor necrosis factor (rhTNF) administered in mice. Sho-saiko-to was noted to protect the rhTNF-induced lethality in galactosamine-hypersensitized mice, and also Sho-saiko-to pretreated mice was protected against the decrease of rectal temperature after rhTNF administration. On the other hand, there was a remarkable enhancement of antitumor activity of rhTNF by Sho-saiko-to pretreatment. These results suggest that Sho-saiko-to drug may protect mice from severe shock syndrome induced by rhTNF.

Endotoxin- and inflammation-induced depression of the hepatic drug metabolism in rats

Carrageenan-induced inflammation and exposure to endotoxin considerably decreased the content of cytochrome P-450 and activities of ethylmorphine N-demethylase and meperidine N-demethylase, but did not decrease the activities of aniline hydroxylase or NADPH-cytochrome c reductase, compared with the respective activities in rats treated with carrageenan alone. These results suggest that under these experimental conditions, the two host-related environmental factors interact and enhance a decrease in rat hepatic microsomal drug metabolizing enzymes depending on the substrate used.

Induction of hepatic cytochrome P-450 and drug metabolism by doxapram in the mouse

The ability of doxapram (20 mg/kg, i.p. daily for 5 days) to induce hepatic cytochrome P-450 and xenobiotic metabolism was examined in male mice. Compared with the control values, the doxapram treatment significantly increased the amount of cytochrome P-450, and activities of aminopyrine N-demethylase, ethylmorphine N-demethylase and meperidine N-demethylase. In contrast, there were no changes in the activities of aniline hydroxylase, 7-ethoxycoumarine deethylase, NADPH-cytochrome c reductase and NADH-ferricyanide reductase, and cytochrome b5 content. These data show that there is a substrate specificity in the ability of doxapram to induce the hepatic drug metabolism in male mice.

Hepatic drug metabolizing activity in rats with carrageenan-induced inflammation

Effect of carrageenan-induced inflammation on hepatic drug metabolism was studied in male and female Wistar rats. One day after treatment of male and female Wistar rats with carrageenan (1%, 0.1 ml, s.c.) (i) a prolongation of the duration of sleeping time induced by hexobarbital (100 mg/kg, i.p.), (ii) decreases biotransformation of hexobarbital, aminopyrine and ethylmorphine in the hepatic 9000 x g supernatants (S-9) and (iii) a decrease in cytochrome P-450 content were observed in males but not female rats. However, carrageenan treatment did not alter aniline hydroxylase activity in animals of either sex. Carrageenan also suppressed induction of hexobarbital, aminopyrine and ethylmorphine metabolism by phenobarbital treatment, and depressed the induction of hepatic S-9 cytochrome P-450 content caused by phenobarbital treatment. These data show that there is a sex-related difference in the ability of carrageenan to alter hepatic drug metabolism, which is substrate-specific, in the rats.

Effect of chlorpromazine on the toxicity of doxorubicin in mice

The effect of chlorpromazine (CPZ) on the toxicity of doxorubicin (DOX) were investigated in mice. CPZ significantly enhanced the acute toxicity and bone marrow toxicity induced by DOX. These results suggest the potentiation of DOX toxicity by CPZ is due to increase of sensitivity of mice to DOX.

Perturbation of metabolism and disposition of cyclophosphamide by interferon and poly I:C, an interferon inducer, in mice

The effects of interferon and poly I:C on the metabolism and disposition of cyclophosphamide were investigated in mice. Elimination of cyclophosphamide from the blood was decreased in mice treated 24 hr previously with interferon (2.5 x 10(6) U/kg, intraperitoneally) or poly I:C (10 mg/kg, intraperitoneally). The blood half-life of cyclophosphamide in interferon or poly I:C-pretreated mice was prolonged to a first order of disappearance of 29.3 and 41.6 min., respectively, compared to 19.0 min. in control mice. Also, the rate of formation of activated cyclophosphamide was delayed and the peak blood level of activated cyclophosphamide was not as high in poly I:C-pretreated and interferon-pretreated mice as in control mice. The decreased elimination and elevated blood levels of activated cyclophosphamide were reflected by changes in its antitumour activity and toxicity in the mice. In 9,000 x g supernatants prepared from the liver homogenate of mice treated with interferon or poly I:C, the oxidation of cyclophosphamide in vitro has decreased by 29 and 37%, respectively. However, the addition of these agents to normal 9,000 x g supernatant suspensions had no effect on cyclophosphamide oxidation. Modulation of the metabolism and disposition resulted from depressed levels of cytochrome P-450 in the hepatic microsomes of the mice administered interferon or poly I:C.

Potentiation of pirarubicin cytotoxicity by dipyridamole in doxorubicin-resistant mouse P388 leukemia cells

The activity of dipyridamole and its possible mechanisms which reverse the resistance of pirarubicin were studied in a P388 mouse leukemia cell lines. Dipyridamole alone was minimally cytotoxic in both of the doxorubicin-resistant cell line (P388/DOX) and the sensitive parent cell line (P388/S), but reversed pirarubicin-resistance in a dose-related manner in P388/DOX cells. A similar dose-response relationship was observed for dipyridamole by increasing net intracellular pirarubicin accumulation. The increase was a result of secondary blocking of enhanced pirarubicin efflux from P388/DOX cells. In contrast, dipyridamole did not affect cytotoxicity and transport in the drug-sensitive cell line. It is suggested that dipyridamole is a useful drug for modulation of the multidrug-resistance of cells.

Preliminary evidence for bacterial endotoxin therapeutics of paraquat lethality in mice

In mice treated with endotoxin (LPS) extracted from Escherichia coli (1 mg/kg, i.p.), 3 hr after paraquat (70 mg/kg, i.p.) a delay in the appearance of deaths and a decrease in their number in 10-day cumulative mortality were observed in comparison to those injected with saline after paraquat.

Effect of cepharanthine on doxorubicin cytotoxicity in P388 murine leukemia cells in vitro and in vivo

The effect of cepharanthine on the cytotoxicity of doxorubicin (DOX) in p388 leukemia cells was studied in vitro and in vivo. Nontoxic levels of cepharanthine enhanced the sensitivity to doxorubicin in p388 cells in vitro. The potentiation of antitumor activity of DOX by cepharanthine against mice bearing p388 cells was also observed.

Drug interaction effects on antitumour drugs (VIII): prevention of ifosfamide-induced urotoxicity by disulfiram and its effect on antitumour activity and acute toxicity of alkylating agents in mice

To reduce the side-effects and to enhance the antitumour activities of antitumour agents, we have been investigating their combined use with routine drugs. In the present study, we examined the effects of disulfiram (DSF) in combination with ifosfamide (IFX). DSF prevented IFX-induced bladder damage in a dose-dependent manner in tumour-free ddY mice when orally administered simultaneously with antitumour agent, but failed to diminish the acute lethal toxicity or leukocytotoxicity of IFX. Diethyldithiocarbamate (DDTC) prevented IFX-induced bladder damage when administered simultaneously with IFX or 1 to 5 hr afterwards. The antitumour activity of IFX in ddY-mice inoculated with Sarcoma 180 or in C57BL/6J mice inoculated with EL-4 leukaemia was not impaired when it was given simultaneously with DSF or 3 hr before DDTC. Thus, neither DSF nor DDTC impaired the antitumour effect of IFX and both diminished its adverse effects. The bladder protection of DSF and DDTC appeared resulted from adduct formation with acrolein and not from inhibition of the metabolic activation of IFX.

Potentiation of antitumor activity of pirarubicin by chlorpromazine in mice bearing doxorubicin-resistant P388 leukemia

Chlorpromazine enhanced the cytotoxicity of pirarubicin against doxorubicin-resistant P388 leukemia cells in colony forming assays. Chlorpromazine also prolonged the survival of mice bearing doxorubicin-resistant P388 leukemia, when given in combination with pirarubicin.

Reversal of resistance to doxorubicin with cepharanthine in murine P388 leukemia cells

Cytotoxic effect in vitro and antitumor effect in vivo of doxorubicin (DOX) combined with cepharanthine were investigated on DOX-resistant murine P388 leukemia (P388/R) cells. Cepharanthine was minimally cytotoxic in the cell line, but reversed DOX-resistance in a dose-related manner in P388/R cells. The administration of cepharanthine to mice bearing the P388 leukemia enhanced the antitumor activity of DOX. These results indicate that cepharanthine is an effective agent to reverse DOX-resistant cells.

Potentiation of cisplatin lethality by bacterial lipopolysaccharide pretreatment in mice

The present study was designed to determine whether bacterial endotoxin (LPS) affects the lethality of cisplatin. Mice treated with LPS (1 mg/kg, i.p.) 24 hr and 1 hr before cisplatin had markedly increased the lethality and nephrotoxicity of cisplatin.

Antidotal effect of lipopolysaccharide against acetaminophen-induced mortality in mice

The possibility that pretreatment with LPS (lipopolysaccharide obtained from Escherichia coli), an immune system stimulant and interferon inducer, could prevent the hepatotoxic effects of acetaminophen (NAPAP) was investigated in mice. When mice were pretreated with LPS (4 mg/kg), intraperitoneally for 24 hr the mortality caused by NAPAP was considerably reduced. Histological examination of the livers and leakage of the enzymes into the blood demonstrated that NAPAP-induced necrosis was decreased in LPS-treated mice compared to that induced by NAPAP alone. Pretreatment with 400 mg/kg or 800 mg/kg of NAPAP decreased the amount of covalently-bound acetaminophen metabolites. Since the level of hepatic glutathione and microsomal cytochrome P-450 were depressed in these experiments, it is concluded that LPS depresses the cytochrome P-450 species responsible for the formation of the toxic metabolites and that less reactive species are available for binding to cell macromolecules.

The effect of phenobarbital on the impairment of drug metabolism by carrageenan-induced inflammation in male rat

Treatment of male rats with phenobarbital markedly stimulated, the activity of the hepatic microsomal monooxygenase system while in rats bearing carrageenan-induced inflammation the activity of this system was lowered. When both agents were administered together, the stimulatory effect of phenobarbital and the inhibitory effect of carrageenan-induced inflammation cancelled each other.

[Augmentation of pirarubicin cytotoxicity by chlorpromazine in doxorubicin-resistant mouse P388 leukemia cells]

The intracellular uptake, retention and cytotoxicity of pirarubicin, an anthracycline derivative, combined with chlorpromazine were investigated in doxorubicin-resistant mouse P388 leukemia (P388/DXR) cells. The number of viable cells was determined by the dye exclusion method. Chlorpromazine increased the cytotoxicity of pirarubicin in a dose-related manner in P388/DXR cells. A similar dose-response relationship was observed for chlorpromazine in increasing net intracellular pirarubicin accumulation. The accumulation was based on block of enhanced pirarubicin efflux from resistant cells by chlorpromazine. However, chlorpromazine did not affect cytotoxicity or transport of pirarubicin in the drug-sensitive cell line. The possible mechanisms of the restoration of pirarubicin sensitivity in P388/DXR cells by chlorpromazine are discussed.

Sex-related differences in drug-metabolizing enzyme activity of rats in carrageenan-induced inflammation

Sex related differences in drugs metabolizing enzymes was studied using Wistar-rats bearing carrageenan-induced edema. One day after treatment with carrageenan, aminopyrine N-demethylase activity was inhibited in males but not in females. Carrageenan treatment did not alter the activity of aniline hydroxylase in either sex of the rats. These data show that there is a sex-related difference in the ability of carrageenan to alter the hepatic drug metabolism, which is substrate specific, in the rat.

Prevention of acetaminophen-induced hepatotoxicity by endotoxin in mice

A preliminary trial was conducted to determine if endotoxin would prevent acetaminophen (APAP)-induced hepatic toxicity. When mice were pretreated with endotoxin (1, 2 and 4 mg/kg, i.p.), the clinical chemistry profile and pathological alterations caused by APAP were reduced with a dose dependent manner. The efficacy of endotoxin in preventing APAP-induced hepatic necrosis should be further studied.

Amino acid sequence of a lectin from Japanese frog (Rana japonica) eggs

The complete amino acid sequence and the location of disulfide bonds of a lectin from Japanese frog (Rana japonica) eggs, which specifically agglutinates transformed cells, are presented. The sequence was determined by analysis of peptides generated by digestion of the S-carboxyamidomethylated protein with Achromobacter protease I, or chymotrypsin, and by chemical cleavage with BNPS-skatole or cyanogen bromide. The lectin is a single-chain protein consisting of 111 residues, with a pyroglutamyl residue at the amino terminus. Four disulfide bonds link half-cystinyl residue 19 to 72, 34 to 82, 52 to 97, and 94 to 111. The sequence and the location of the disulfide bonds are highly homologous to those of bull frog (Rana catesbeiana) egg S-lectin. They are also homologous to human angiogenin, a tumor angiogenesis factor, and a family of pancreatic ribonucleases.

The deleterious effect of buthionine sulfoximine, a glutathione-depleting agent, on the cisplatin toxicity in mice

Pretreatment of buthionine sulfoximine (500 mg/kg, i.p., BSO), a potent glutathione-depleting agent, markedly increased the lethality and nephrotoxicity of cisplatin. These results suggest that a reactive electrophilic intermediate may be involved in the mechanism of cisplatin nephrotoxicity and moreover, that renal glutathione may play a protective role against cisplatin-induced nephrotoxicity.

[Analysis of protein band pattern in gingival crevicular fluid. Character and clinical comparison between healthy subjects and periodontal disease patients]

We have been studied the characteristics of protein components in gingival crevicular fluid (GCF) with isoelectric focusing technique. The purpose of this study was to investigate the relationship between those proteins and clinical findings such as Gingival Index (Loe & Sillness), Pocket depth, Plaque Index (Quigley & Hein), Gingival Bleeding Index and Bone Index. GCF, serum and mixed saliva collected from the same subject were analyzed, and following results were obtained. The patterns of protein bands in GCF were similar to those in serum but different from mixed saliva, and the pI of main protein band of GCF and serum were 4.9. No apparent difference was observed on the patterns between clinically healthy gingiva and those received periodontal disease. Protein patterns were compared with the before mentioned clinical findings and GCF volume. Main protein bands were observed on cathode side (pI 8.0-9.0) at the patterns against Gingival Index: 0-1 or greater than 2, Gingival Bleeding Index: + or -, Pocket Depth: 0-1 or greater than 2 and Bone Index: 1 or greater than 3. It was suggested that the study of the proteins on cathode side is important.

Comparative studies of carbohydrate-binding proteins from Xenopus laevis skin and eggs. Sugar-binding specificities and affinity purification

Salt and detergent extracts of acetone-dried powder of Xenopus laevis skin and eggs were fractionated on sugar-Sepharose columns, to which lactose, melibiose, galactose, rhamnose and mannose had been covalently linked, by successive elution with chelating reagent and specific sugars, resulting in separation of the different Ca2(+)-dependent and Ca2(+)-independent carbohydrate-binding proteins. The skin of X. laevis contains a salt-extractable Ca2(+)-dependent lactose-binding lectin of 30 kilodalton (kDa) and the eggs a similar lectin of 43 kDa, but they both lack Ca2(+)-dependent galactose-binding lectins. The 30 kDa lactose-binding lectin which agglutinates human A erythrocytes was isolated by successive affinity chromatography on two linked sugar-Sepharose columns, i.e., a galactose-Sepharose-lactose-Sepharose (GL) column system. Since the 30 kDa lectin was not recovered in the Ca2(+)-dependent lactose-binding protein fraction from the GL column system under the dithiothreitol (DDT)-free conditions, it was concluded that the lectin requires the presence of DTT and calcium for binding to the lactose-Sepharose column.

Enhancement of cisplatin toxicity by buthionine sulfoximine, a glutathione-depleting agent, in mice

Pretreatment of buthionine sulfoximine (500 mg/kg, i.p., BSO), a potent glutathione-depleting agent, markedly increased the lethality and nephrotoxicity of cisplatin. These results suggest that a reactive electrophilic intermediate may be involved in the mechanism of cisplatin nephrotoxicity and moreover, that renal glutathione may play a protective role against cisplatin-induced nephrotoxicity.