Antitumorigenic activities of chalcones. I. Inhibitory effects of chalcone derivatives on 32Pi-incorporation into phospholipids of HeLa cells promoted by 12-O-tetradecanoyl-phorbol 13-acetate (TPA)

More than forty chalcone derivatives were synthesized to examine their structure-activity relationship against tumorigenesis. As a primary screening test, the inhibitory activities of the chalcones for the 32Pi-incorporation into phospholipids of HeLa cells enhanced by 12-O-tetradecanoyl-phorbol 13-acetate (TPA) were examined. 3-Hydroxy-chalcone derivatives possessing methyl group in 3'-, 4'-, or 2'-position and isoliquiritigenin homologs showed potent inhibitory activities in the phosphorylation test, which suggests their antitumorigenic effects.

Fv fragment-mediated crystallization of the membrane protein bacterial cytochrome c oxidase

Crystallization of membrane proteins, a prerequisite for their X-ray crystallographic analysis, remains difficult. Here, we demonstrate that the crystallization of the cytochrome c oxidase from Paracoccus denitrificans can be mediated by co-crystallization with an antibody Fv fragment. The crystals obtained contain all four subunits of this membrane protein complex and the Fv fragment. The approach of co-crystallizing membrane proteins with antibody fragments should be useful in obtaining well-ordered crystals of membrane proteins in general.

Electron transfer from the tetraheme cytochrome to the special pair in the Rhodopseudomonas viridis reaction center: effect of mutations of tyrosine L162

The structure of the photosynthetic reaction center (RC) from Rhodopseudomonas viridis is known to high resolution. It contains a firmly bound tetraheme cytochrome from which electrons are donated to a special pair (P) of bacteriochlorophylls, which is photooxidized upon absorption of light. Tyrosine at position 162 of the L-subunit of the reaction center (L 162 Y) is a highly conserved residue positioned halfway between P and the proximal heme group (c-559) of the cytochrome. By specific mutagenesis this residue was exchanged against the amino acids phenylalanine (F), glycine (G), methionine (M), leucine (L), tryptophan (W), threonine (T), and histidine (H). All mutants were expressed in Rps. viridis using a recently established transformation system [Laussermair & Oesterhelt (1992) EMBO J. 11, 777-783]. They were shown biochemically to synthesize all four subunits of the RC (cytochrome, subunits L, M, and H) and to assemble them correctly into the membrane. The structures of two mutants (L 162 F and L 162 T) were determined and found not to differ significantly from the wild-type structure. All mutants grew photosynthetically. The absorption spectrum of all the mutants is the same as in WT, but the redox potential of P and of c-559 was changed by the mutations. The kinetics of electron transfer from the heme group to the special pair were measured in chromatophores by flash absorption. As found earlier in the wild type (Y) several exponential components were needed to fit the data.(ABSTRACT TRUNCATED AT 250 WORDS)

[Pharmacokinetic and clinical studies with azithromycin (fine granule) in the pediatric field. Pediatric Study Group of Azithromycin]

Azithromycin (AZM) in 10% fine granules, a newly developed azalide antibiotic, was administered at a standard dose of 10 mg/kg once daily for 3 to 5 days (89.5% received 3 day administration) to children with infectious diseases and the efficacy and the safety of AZM were investigated. In addition AZM concentrations were determined in blood samples from 18 patients and in urine samples from 17 patients to examine o pharmacokinetic characteristics of AZM. 1. Absorption and excretion: Cmax's in 16 patients who received 10 mg/kg and 2 patients who received 20 mg/kg were 0.29 +/- 0.24 micrograms/ml and 0.75 micrograms/ml, respectively, while T 1/2's were 42.0 +/- 11.8 hours for the former and 51.3 hours for the latter. AUC(0 to approximately infinity)'s were 10.72 +/- 5.00 micrograms x hr/ml in the former and 28.83 micrograms x hr/ml in the latter. Urinary concentrations of AZM peaked at 48 to 72 hours after the administration of 10 mg/kg AZM in 14 patients, while it peaked at 24 to 48 hours in the patients who received 20 mg/kg. Urinary recovery rates in the first 120 hours after the start were 9.1 +/- 2.6% for 10 mg/kg and 10.8 +/- 3.4% for 20mg/kg. 2. Clinical efficacy: The study received 619 entries and 564 cases were evaluated for drug efficacy. The remaining were not evaluated because of dropout or exclusion. The efficacy rate, combining both "Excellent" and "Good" cases was 94.3% in 246 cases where pathogens were identified, classified as Group A. The efficacy rate was 90.7% for the remaining 321 cases, classified as Group B, where causative pathogens were unidentified. The difference between the two groups was no statistical significance. The combined efficacy rate was 92.2%. For the 116 cases where the patients had failed to respond to previous chemotherapies instituted for 3 days or longer, the efficacy rate for AZM was 94.0%. 3. Adverse reactions and abnormal laboratory tests: Incidents of diarrhea, soft stool, skin rashes, or vomiting were found in 15 patients (2.5%) of 596 cases eligible for evaluation. These reactions, however, were all transient and mild to moderate in severity in the 15 patients including 4 patients for whom the treatment was discontinued, all resolved in time. Abnormal changes in laboratory tests were found as follows: decrease in WBC in 23 patients (5.6%), increase in eosinophils in 28 (7.1%), increase in platelet count in 2 (0.5%), decrease in platelet count in 1 (0.3%), elevation of GOT in 3 (0.8%), and elevation of GPT in 6 (1.6%).(ABSTRACT TRUNCATED AT 400 WORDS)

[Pharmacokinetic and clinical studies with azithromycin (capsule) in the pediatric field. Pediatric Study Group of Azithromycin]

Azithromycin (AZM) in 100 mg capsules, a newly developed azalide antibiotic, was administered at a standard dose of 10 mg/kg once daily for 3 to 5 days (89.9% received 3 day administration) to children with infectious diseases and the efficacy and the safety of AZM were investigated. In addition, AZM concentrations were determined in blood samples from 9 patients and in urine samples from 12 patients to examine pharmacokinetic characteristics of AZM. 1. Absorption and excretion: Cmax was 0.45 +/- 0.28 micrograms/ml, T 1/2 was 52.7 +/- 20.2 hours, and AUC(0 approximately to infinity) was 12.09 +/- 4.93 micrograms.hr/ml in the 9 patients each of whom received 8.5 to 14.3 mg/kg AZM. Urinary concentrations of AZM peaked at 48 to 72 hours after the administration of 8.5 to 14.7 mg/kg AZM in 12 patients and the average urinary recovery rate in 120 hours was 7.3 +/- 2.8%. 2. Clinical efficacy: The study received 139 entries and 119 cases were evaluated for drug efficacy. The remaining were not evaluated because of dropout or exclusion. The efficacy rate combining both "Excellent" and "Good" cases, was 100% for 40 cases in which pathogens were identified, classified as Group A. The efficacy rate was 97.5% for the remaining 79 cases, classified as Group B, where causative pathogens were unidentified. The difference between the two groups was no statistical significance. The combined efficacy rate was 98.3%. For the 31 cases where the patients had failed to respond to the previous chemotherapies instituted for 3 days or longer, the efficacy rate for AZM was 93.5%. 3. Adverse reactions and abnormal laboratory tests: 8 incidents of diarrhea, skin rashes, urticaria, or vomiting were found in 7 patients (5.4%) of 130 cases eligible for evaluation. These reactions, however, were all transient and mild to moderate in severity in the 7 patients including 2 patients for whom the treatment was discontinued, all resolved in time. Abnormal changes in laboratory tests were found as follows: decrease in WBC in 10 patients (9.3%), an increase in eosinophils in 12 (11.4%), an increase in platelet count in 1 (1.0%), an elevation of GOT in 3 (3.1%), an elevation of GPT in 6 (6.2%), and an elevation of LDH in 1 (1.1%). The abnormalities were transient and did not require particular intervention. Moreover, none of the patients indicated clinical signs associated with the abnormal changes of laboratory tests.(ABSTRACT TRUNCATED AT 250 WORDS)

Strong anti-mutagenic activity of the novel lipophilic antioxidant 1-O-hexyl-2,3,5-trimethylhydroquinone against heterocyclic amine-induced mutagenesis in the Ames assay and its effect on metabolic activation of 2-amino-6-methyldipyrido[1,2-a:3',2'-d] imidazole (Glu-p-1)

Antimutagenic effects of a novel lipophilic antioxidant, 1-O-hexyl-2,3,5-trimethylhydroquinone (HTHQ), and other known antioxidants against heterocyclic amine- or other mutagen-induced mutagenesis were examined in the Ames assay using Salmonella strain TA 98 to access the chemo-preventive effects of antioxidants on heterocyclic amine-induced carcinogenesis. Further the mechanisms of inhibition by HTHQ were accessed. HTHQ was shown to potently inhibit mutagenesis induced by all of 8 different heterocyclic amines at rates between 100% and 63% in the presence of S9 mix. When the protection of HTHQ against 2-amino-6- methyldipyrido[1,2-alpha:3',2'-d]imidazole (Glu-P-1)-induced mutagenesis was compared with known antioxidants t-butylhydroquinone, propyl gallate, BHA, BHT and alpha-tocopherol, HTHQ showed the greatest effect. Among hexyl, butyl, ethyl and methyl derivatives of 1-O-alkyl-2,3,5-trimethylhydroquinone, HTHQ was the most effective in inhibiting Glu-P-1-, 3-amino-1-methyl-5-H-pyrido[4,3-b]indole (Trp-P-2)- or 2-amino-3-methylimidazo[4,5-f]quinoline (IQ)-induced mutagenesis. On the other hand, HTHQ did not inhibit mutagenic activity induced by other mutagens such as N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (AF-2) and benzo[a]pyrene. HTHQ weakly inhibited that due to direct mutagen 2-nitro derivative of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) only in the presence of S9 mix. No such influence on a 2-nitro derivative of 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ) or 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-induced mutagenesis, was observed with or without the S9 mix. HTHQ slightly inhibited mutagenesis induced by activated Glu-P-1, a direct acting proximate metabolite of Glu-P-1, in the absence of the S9 mix. HPLC analysis revealed activated Glu-P-1 to be formed by incubating Glu-P-1 with the S9 mix, but this was considerably decreased by the addition of HTHQ. These results indicate that HTHQ is a powerful antimutagenic compound and specifically acts against heterocyclic amines. Its antimutagenic activity appeared to exert by both inhibiting metabolic activation of heterocyclic amines and action on activated N-hydroxy species.

Structure at 2.8 A resolution of cytochrome c oxidase from Paracoccus denitrificans

The crystal structure at 2.8 A resolution of the four protein subunits containing cytochrome c oxidase from the soil bacterium Paracoccus denitrificans, complexed with antibody Fv fragment, is described. Subunit I contains 12 membrane-spanning, primarily helical segments and binds haem a and the haem a3-copper B binuclear centre where molecular oxygen is reduced to water. Two proton transfer pathways, one for protons consumed in water formation and one for 'proton pumping', could be identified. Mechanisms for proton pumping are discussed.

Quantitative analysis of redox gradient within the rat liver acini by fluorescence images: effects of glucagon perfusion

The redox gradient along the sinusoid in the rat liver was studied using a redox scanner, a device based on tissue fluorescence scanning spectroscopy measuring the fluorescence signals of oxidized flavoprotein (FP) and reduced pyridine nucleotide (PN). The FP/(FP+PN) ratio reflects the mitochondrial redox state in the liver tissue. The distribution of mitochondrial redox state on the scanned area is expressed as two-dimensional gray-scale images with a 20 micron resolution. Using this instrument, we have scanned a 2.5 x 2.5 mm area of the frozen rat liver sample to investigate the redox gradient within acini and the effects of glucagon on the changes in the redox distribution. The redox images obtained in the perfused livers showed mosaic patterns implicating a regular heterogeneity of redox state in an acinus. The analysis of gradient curve, furthermore, clarified that the redox level in an acinus decreased sigmoidally from the periportal to the pericentral region. Glucagon, which has been reported to reduce the intracellular redox state, decreased the redox potential in whole acini, especially, in the periportal region, when compared with the perfusion without glucagon. These results strongly indicate an intraacinus heterogeneity of glucagon function, with glucagon selectively operating in the upstream of the sinusoid.

Intraarterial perfusion of the hindlimb with pyridoxalated hemoglobin polyoxyethylene conjugate solution in anesthetized dogs

To evaluate the potential clinical usefulness of a modified hemoglobin, pyridoxalated hemoglobin polyoxyethylene conjugate (PHP), the hindlimb vascular bed was perfused with PHP solution while monitoring tissue oxygen tension (PtO2) in anesthetized dogs. The hindlimb region was perfused through the external iliac artery with a roller pump at a varying perfusion rate. PtO2 was measured using a PO2-monitoring probe inserted into the gracial muscle. After surgical preparation for perfusion, the iliac arterial flow rate was 19.9 +/- 5.6 ml/min, and baseline PtO2 was 38.4 +/- 1.3 mm Hg. Perfusion with autologous arterial blood with the pump increased PtO2 and perfusion pressure (PP) in a perfusion rate-dependent manner. Perfusion with PHP solution at 20 ml/min decreased PtO2 from the initial baseline level, but an increase in the flow rate to 40-55 ml/min restored or induced an elevation of PtO2. Results demonstrated that PHP solution can deliver oxygen to local tissue and maintain tissue oxygen tension at the same level as autologous arterial blood at a high enough flow rate.

Suppression of adult T cell leukemia-derived factor/human thioredoxin induction by FK506 and cyclosporin A: a new mechanism of immune modulation via redox control

Adult T cell leukemia-derived factor (ADF), which is identical to a disulfide reducing enzyme human thioredoxin (TRX), is produced and released by activated or virus-infected lymphocytes. Here we report that, in peripheral blood mononuclear cells (PBMC) stimulated with phytohemagglutinin (PHA), ADF/TRX mRNA was induced within 8 h after stimulation as detected by in situ hybridization study. To analyze the mechanism of ADF/TRX induction during T cell activation, the effects of immunosuppressants including FK506, rapamycin (Rap) and cyclosporin A (CsA) on ADF/TRX expression were investigated by immunoblot analysis. ADF/TRX induction in PBMC by PHA, Con A or OKT3 mAb was almost completely suppressed by FK506. Whereas CsA also inhibited ADF/TRX expression in OKT3 mAb-stimulated PBMC, Rap failed to affect it in spite of exhibiting growth inhibition. In addition, exogenous IL-2 could not increase ADF/TRX production in FK506-treated PBMC or in PHA blasts. These results indicate that ADF/TRX induction in T cell activation depends on calcineurin-dependent events in the early phase and that IL-2 production is not directly involved in ADF/TRX induction. Furthermore, when recombinant ADF (rADF) was added to a culture of PBMC 1 h before the addition of PHA and FK506, the action of FK506 was partially reversed as determined by [3H]thymidine incorporation and viable cell counts. These results suggest that ADF/TRX produced and released from PBMC may be a crucial event in lymphocyte activation, and that FK506 and CsA may exert the immune suppression partly through inhibiting the induction of the endogenous reducing factor ADF/TRX.

Immunoelectron microscopy and epitope mapping with monoclonal antibodies suggest the existence of an additional N-terminal transmembrane helix in the cytochrome b subunit of bacterial ubiquinol:cytochrome-c oxidoreductases

The topology of the ubiquinol:cytochrome-c oxidoreductase (cytochrome bc1 complex) from Paracoccus denitrificans was investigated by immunoelectron microscopy with sequence-specific murine monoclonal antibodies. Epitope mapping with synthetic peptides and enzymic proteolytic cleavage of the cytochrome bc1 complex were employed to localize precisely the respective antibody epitopes on the subunits of this membrane protein complex. Localization of defined epitopes on the cytochrome bc1 complex by immunoelectron microscopy clearly demonstrates that the N-terminus of the cytochrome b subunit is exposed to the periplasmic space. This finding is in agreement with a nine-transmembrane-helices topology model (I-IX) as predicted before for cytochrome b. However, due to other published evidence we favour the existence of an additional transmembrane helix (helix 0) complementing a more recently published eight-helices model (A-C,cd, D-H), at least for prokaryotes.

Pharmacological characteristics of the canine cerebrovascular constriction produced by neuropeptide Y

In order to elucidate the role of neuropeptide Y (NPY) in cerebral circulation, we undertook the present study to examine the action of NPY itself, and the combined effects of NPY with other vasoconstrictor stimuli. NPY itself produced contractions of isolated canine basilar artery in a concentration-dependent manner, which was independent of the presence or absence of endothelium. C-terminal peptides of NPY (NPY12-36) and (NPY22-36) were weak agonists, while those without C-terminals were ineffective. The vasoconstriction produced by NPY was, however, strongly potentiated by increasing the K+ concentration in the medium up to 20 mM, or by pretreatment with tetraethylammonium, a K+ channel blocker and hemolysate containing oxyhemoglobin. NPY also augmented the contractile responses to prostaglandin F2 alpha, norepinephrine, and histamine, but not to serotonin. The contraction in response to NPY per se or in 20 mM K+ was effectively attenuated by Ca2+ antagonists such as d-cis-diltiazem, and in a Ca(2+)-free medium. These results suggest that in canine basilar artery, the activation of the Y1 receptor modulates the availability of the L-type Ca2+ channel, leading to enhance Ca2+ influx from the extracellular space and potentiate contractile effects of other cerebral vasoconstrictors. This might be involved in the cerebral vasospasm which occurs after subarachnoid hemorrhage.

Thiol-mediated redox regulation of apoptosis. Possible roles of cellular thiols other than glutathione in T cell apoptosis

Thiol redox status modulates various aspects of cellular function. We demonstrate that oxidation of cellular sulfhydryl (SH) groups induces apoptosis. In Jurkat T cells and human PBL blasts, the fraction of apoptotic nuclei increased after treatment with an SH-specific oxidant, diamide. Analysis of DNA fragmentation and nuclear morphology also indicated that SH oxidation could induce apoptosis. In the apoptosis induced by SH oxidation, the decrease of cellular glutathione was transient and the increase of glutathione disulfide was observed only after apoptotic changes had occurred. Depletion of cellular glutathione with buthionine sulfoximine failed to induce apoptosis, despite a marked decrease of cellular glutathione, which was greater than that observed in apoptosis induced by diamide. Thus, the changes of cellular glutathione or glutathione disulfide may not be the major cause of apoptosis induced by diamide. Intracellular adult T cell leukemia-derived factor/human thioredoxin, another thiol-related antioxidant protein, was oxidized by incubation with diamide. These results suggest that thiol redox status is one of the key factors of the apoptotic pathway in which thiols other than glutathione may play even more critical roles.

Coexisting type III hyperlipoproteinemia and familial hypercholesterolemia: a case report

A 39-year-old man presented with type III hyperlipoproteinemia in association with heterozygous familial hypercholesterolemia (FH). He had extensive tuberous xanthomas over the knees and elbows and xanthomas in the Achilles tendons. He also had palmar xanthomas. He exhibited severe hypercholesterolemia and hypertriglyceridemia. This patient was heterozygous for FH, as evidenced by low low-density lipoprotein (LDL) receptor function on lymphocytes, and had type III hyperlipoproteinemia, as determined by apolipoprotein (apo) E phenotype 2/2 in isoelectric focusing of the E isoproteins and the presence of a broad beta band on electrophoresis. Because therapy consisting of diet restrictions and lipid-lowering agents such as clinofibrate and niceritrol did not decrease serum total cholesterol ([TC] 15.26 mmol/L) and triglyceride ([TG] 10.79 mmol/L) levels effectively, the patient underwent plasmapheresis once every 2 weeks using a dextran sulfate-cellulose column. Repeated plasmapheresis markedly reduced serum TC and TG and induced complete regression of the palmar xanthoma after 6 months. The severity of tuberous xanthomas on the knees and elbows was reduced after 2.5 years. After plasmapheresis, TC decreased to 1.94 mmol/L from 10.40 mmol/L and TG decreased to 0.33 mmol/L from 7.90 mmol/L. Plasmapheresis performed with a dextran sulfate-cellulose column was highly effective in removing the lipoprotein-remnant particles in this patient, leading to generalized improvement in the lipoprotein profile.

Thiol-mediated redox regulation of apoptosis. Possible roles of cellular thiols other than glutathione in T cell apoptosis

Thiol redox status modulates various aspects of cellular function. We demonstrate that oxidation of cellular sulfhydryl (SH) groups induces apoptosis. In Jurkat T cells and human PBL blasts, the fraction of apoptotic nuclei increased after treatment with an SH-specific oxidant, diamide. Analysis of DNA fragmentation and nuclear morphology also indicated that SH oxidation could induce apoptosis. In the apoptosis induced by SH oxidation, the decrease of cellular glutathione was transient and the increase of glutathione disulfide was observed only after apoptotic changes had occurred. Depletion of cellular glutathione with buthionine sulfoximine failed to induce apoptosis, despite a marked decrease of cellular glutathione, which was greater than that observed in apoptosis induced by diamide. Thus, the changes of cellular glutathione or glutathione disulfide may not be the major cause of apoptosis induced by diamide. Intracellular adult T cell leukemia-derived factor/human thioredoxin, another thiol-related antioxidant protein, was oxidized by incubation with diamide. These results suggest that thiol redox status is one of the key factors of the apoptotic pathway in which thiols other than glutathione may play even more critical roles.

Ca2+ handling mechanisms underlying neuropeptide Y-induced contraction in canine basilar artery

The effects of neuropeptide Y on isometric tension simultaneously measured with cytosolic Ca2+ concentration ([Ca2+]cyt) and Ca2+ sensitivity of contractile elements were studied in isolated canine basilar arteries. Neuropeptide Y (1-100 nM) increased [Ca2+]cyt and tension in a concentration-dependent and parallel manner, whereas 9,11-dideoxy-11 alpha,9 alpha-epoxymethano prostaglandin F2 alpha (U46619) (10-100 nM), a thromboxane A2 mimetic, produced a large contraction with a small increase in [Ca2+]cyt. Ca2+ channel antagonists such as d-cis-diltiazem (10 mM) abolished both [Ca2+]cyt and tension augmented by neuropeptide Y. In Ca(2+)-free solution containing 0.2 mM EGTA, neuropeptide Y did not change [Ca2+]cyt and tension, whereas U46619 transiently increased both of them. Furthermore, neuropeptide Y apparently did not affect the Ca2+ sensitivity when assessed in the artery permeabilized with Staphylococcus aureus alpha-toxin, whereas U46619 augmented it. These findings suggest that neuropeptide Y-induced contraction in the canine basilar artery is produced mainly by Ca2+ influx through L-type Ca2+ channels.

New aerodynamic aspects of nasal patency

In considering possible aerodynamic indicators of subjective nasal stuffiness, we measured nasal resistance, acceleration change of nasal airflow, and alteration of differential pressure and compared those with the degree of severity of sensation of nasal obstruction in 75 patients. The acceleration change of airflow and alteration of differential pressure are presented as an equation: y = ax2 + bx + c, in which "a" represents the approximate shape of the curve. Nasal resistance, on either inspiration or expiration, and coefficient "a" of acceleration change the rapid phase from inspiration to expiration correlated well with subjective nasal patency, while coefficient "a" of acceleration change the rapid phase from expiration to inspiration and alteration of differential pressure either the rapid phase from inspiration to expiration or from expiration to inspiration did not correlate well with perception of nasal blockage. It seems that measurement of respiratory acceleration of airflow of quiet nasal breathing is a useful indicator of subjective nasal patency.

Rational use of oral antibiotics for pediatric infections

We carried out a survey in Japan to investigate compliance among children given oral antibiotics in an outpatient setting. The results of our survey revealed that, in Japan, approximately one-quarter of patients did not take their full course of antibiotics. Reasons for unsupervised self-discontinuation included: (1) the parent or guardian judged the infection to be cured; (2) the child refused to take the drug; and (3) the appearance of side effects. Causative organisms often involved in respiratory infections experienced in out-patient medicine include pneumococci, streptococci, staphylococci, Haemophilus influenzae, Moraxella (Branhamella) catarrhalis and Mycoplasma pneumoniae. The beta-lactams are effective against all of these bacterial species, with the exception of M. pneumoniae. We conducted a survey of beta-lactam antibiotics currently on the Japanese market and compared them to other oral antibiotics used to treat respiratory infections. Ease of administration, based on the incidence of adverse effects, particularly diarrhea, the dosage form, taste, dosage per administration and the number of doses required per day, are reported.

Effects of pyridoxalated hemoglobin polyoxyethylene conjugate and other hemoglobin-related substances on arterial blood pressure in anesthetized and conscious rats

The effects of pyridoxalated hemoglobin polyoxyethylene conjugate (PHP) and other hemoglobin-related substances on arterial blood pressure (ABP) and heart rate (HR) were examined. Infusion of PHP and other hemoglobin-related substances elevated ABP and increased HR. The degree of the increase in ABP and HR did not differ among the groups. There were species' differences in responses to PHP. Pretreatment with various blockers did not abolish the elevation of ABP. The pretreatment of NG-monomethyl-L-arginine dose-dependently reduced the elevation of ABP but did not completely abolish it. PHP also elevated ABP in conscious rats. The magnitude of the ABP elevation was significantly smaller than in the anesthetized rats. Results indicate that inhibition of nitric oxide (NO) might be responsible in part for the elevation of ABP, and the degree of the elevation would be dependent on the degree of contribution of NO to the regulation of ABP.

Deterioration of platelet energy metabolism following energy crisis of liver after hepatectomy

The aim of this study is to investigate the relationship in energy metabolism between the platelet and the liver. The adenylate energy charge of human platelets and arterial ketone body ratio (AKBR:acetoacetate/3-hydroxybutyrate) were measured in 11 patients after hepatectomy. Hepatic energy crisis was defined as the decrease of AKBR below 0.7. The platelet energy charge was measured on the first (Day 1), the second (Day 2), third (Day 3) and sixth (Day 6) day during AKBR decreased and remained under 0.7. The values before AKBR decreased were employed as the control. The values of the platelet energy charge were 0.917 +/- 0.008 in the control (n = 11) and 0.896 +/- 0.009 in all samples after AKBR decreased under 0.7 (n = 30). There was no significant difference between them. The values of energy charge were divided into four groups according to the periods of time after AKBR decreased and remained under 0.7 and compared. The energy charge was 0.923 +/- 0.006 (Day 1, n = 11), 0.907 +/- 0.008 (Day 2, n = 10), 0.890 +/- 0.005 (Day 3, n = 5), and 0.815 +/- 0.012 (Day 6, n = 4). The energy charge of Day 3 was significantly lower than that of Day 1 (p < 0.01). The energy charge of Day 6 was significantly lower than that of Day 1, 2, 3 (p < 0.001, p < 0.001, and p < 0.01, respectively). The 4 patients whose AKBR remained under 0.7 for more than 6 days had hemostatic disorder. The deterioration of the platelet energy charge metabolism lags behind that of the liver.(ABSTRACT TRUNCATED AT 250 WORDS)