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Biomedical subjects

K Sudo

Publications and source records attributed to K Sudo.

At least 253 records · Page 14Linked to original sources

[Effects of gomisin A, a lignan component of Schizandra fruits, on experimental liver injuries and liver microsomal drug-metabolizing enzymes].

Effects of oral administration of gomisin A, one of the components isolated from Schizandra fruits, on liver injuries induced by CCl4, d-galactosamine and dl-ethionine and on liver microsomal drug-metabolizing enzyme activities were investigated. Gomisin A suppressed the increase of serum transaminase activities and the appearances of histological changes such as degeneration and necrosis of hepatocyte, inflammatory cell infiltration and fatty deposition in each type of liver injury. The repeated administration of gomisin A (30 or 100 mg/kg, p.o., daily for 4 days) induced an apparent increase of liver weight in liver-injured and normal rats. Gomisin A decreased serum triglyceride and lipid contents of the liver in biochemical studies. Increases of microsomal cytochrome b5 and P-450, elevations of NADPH cytochrome C reductase, aminopyrine N-demethylase and 7-ethoxycoumarin O-deethylase activities and decrease of 3,4-benzo(a)pyrene hydroxylase activity per cytochrome P-450 were observed after the administration of gomisin A. In addition, gomisin A was found to enhance the incorporation of 14C-phenylalanine into liver protein and to shorten the hexobarbital-induced sleeping time. These changes caused by gomisin A were similar to those by phenobarbital. However, gomisin A is distinctly different from phenobarbital in the finding that phenobarbital lessened the survival ratio of CCl4-intoxicated mice, but gomisin A did not. Our observation suggest that gomisin A shows an antihepatotoxic action by oral application and also has hypolipidemic (mainly triglyceridemic) and liver protein synthesis-facilitating actions and that the enlargement of the liver seen with gomisin A is the adaptive hypertrophy which is due to the induction of drug-metabolizing enzymes.

Animals↗

A case of lactate dehydrogenase (LDH)-IgG complex formation which causes low plasma LDH activity and an abnormal LDH isozyme pattern.

A case of an LDH-IgG complex formation which causes low plasma LDH activity and an abnormal LDH isozyme pattern was reported. A patient had pericarditis and myocardial hypertrophy of asymmetrical septal hypertrophy type. The same IgG was recognized in pericardial effusion. From a column chromatographic study, the molecular weight of LDH-IgG complex was estimated as being about 490,000. This complex was speculated as the IgG1-LDH2. The mechanism by which LDH-IgG is formed and the relationship between the complex itself and cardiac diseases remain unknown.

Aged↗

Isolation and identification of metabolites of ofloxacin in rats, dogs and monkeys.

Metabolites of (+/-)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-7H -pyrido [1,2,3-de][1,4]benzoxazine-6-carboxylic acid (ofloxacin) in excreta of rats, dogs and monkeys after oral administration of 14C-ofloxacin (20 mg/kg) were isolated and identified. Three metabolites of ofloxacin were detected in the excreta of all three species, and identified by t.l.c., u.v., n.m.r. and mass spectrometry as follows: M-1, ester glucuronide of ofloxacin; M-2, unchanged ofloxacin; M-3, (+/-)-9-fluoro-2,3-dihydro-3-methyl-10-(1-piperazinyl)-7-oxo-7H-pyrido [1,2,3-de][1,4]benzoxazine-6-carboxylic acid (desmethyl ofloxacin); M-4, (+/-)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-7H -pyrido [1,2,3-de][1,4]-benzoxazine-6-carboxylic acid piperazine-4-oxide (ofloxacin N-oxide). It is concluded that ofloxacin is metabolized by O-acyl glucuronidation, N-demethylation and N-oxidation.

Animals↗

A case of immunoglobulin G conjugated with lactate dehydrogenase, producing both loss of enzyme activity and an abnormal isoenzyme pattern.

We present a patient with an inhibitor of lactate dehydrogenase (LD; EC 1.1.1.27) in serum, who had pericarditis and myocardial hypertrophy. The patient's LD activity in serum was low and the LD isoenzyme pattern was abnormal. The relative molecular mass of this abnormal LD-IgG complex was approximately 490 000. The patient's IgG reacted with all five LD isoenzymes.

Aged↗

Immunochemical studies on lactate dehydrogenase A subunit deficiencies.

In lactate dehydrogenase (LDH) A subunit deficiency, is there not only a lack of activity but also a lack of subunit production? We demonstrated three remarkable points to answer this question: There are no proteins that immunologically react with anti-A subunits. There are no heterotetramers that react with anti-B subunits. B subunits seem to be genetically produced at normal level, and all of them form only one isoenzyme, LDH-B4. From these points, we concluded that there is a complete lack of A subunit production or production of incomplete A subunits that can neither react with anti-A subunits nor form heterotetramers.

Humans↗

Gangliosides in human and monkey lenses.

The amount of gangliosides was determined in normal human lens, cataractous human lens and normal monkey lens. The total gangliosidic sialic acids averaged 176.3 +/- 44.7 (SD) (n = 4) in normal human lenses, and 272.2 +/- 80.6 (n = 14) nmol per gram wet weight in cataractous lenses, respectively; the difference was statistically significant. In monkey lens, the content was 143.8 +/- 32.4 (n = 4) nmol per gram wet weight. The composition of the gangliosides was analyzed by high performance thin-layer chromatography: the components of the a-pathway biosynthesis comprised 78.3% and 70.2%, and those of the b-pathway 13.8% and 20.9%, in the normal and cataractous human lenses, respectively. In the monkey lens, the components of the a-pathway comprised 33.0% and those of the b-pathway were 56.6% of the total gangliosides. Increase in gangliosides was thought to be related with the mechanism underlying formation of cataract.

Animals↗

Lactate dehydrogenase inhibition by immunoglobulin G in human serum.

Low lactate dehydrogenase (LD; EC 1.1.1.27) activity and an abnormal LD pattern in electrophoretograms of LD isoenzymes in the sera of two patients were caused by inhibition of LD by immunoglobulin G. One of these showed inhibitor activity in the serum upon direct analysis, while the other showed activity only after the immunoglobulin was stripped from the LD. As judged from the LD isoenzyme patterns in serum, the LD inhibitor appeared to act against M subunits. However, quantification of binding affinities to each isolated isoenzyme showed that the LD inhibitor had a stronger effect on LD isoenzymes 2 and 3 (H3M1 and H2M2, respectively).

Aged↗

Erythematosquamous skin lesions in hereditary lactate dehydrogenase M-subunit deficiency.

Peculiar erythematosquamous lesions were observed in two adult patients in Japan with hereditary lactate dehydrogenase M-subunit deficiency. Although these patients showed excessive fatigue and myoglobulinuria after extended exercise, they were usually asymptomatic. However, nonpruritic follicular papules or erythematous patches with scaly edges were present on the extensor surfaces of the extremities of these patients since childhood, showing some improvement after puberty. There were also erythematous patches on the weight-bearing areas of their soles. These patches showed exacerbation and a tendency toward peripheral spreading in summer. These skin lesions provide an important clue in the detection of this genetic enzyme deficiency.

Adolescent↗

Immunochemical approach to the question of inactive subunits in cases of lactate dehydrogenase B subunit deficiency.

If there were enzymatically inactive B subunits in a solution containing lactate dehydrogenase (LD) B4 prepared from the hemolysates of heterozygous individuals with LD-B subunit deficiency, the inactive subunits would compete with normal subunits for antibodies to the B4 subunit. Using the activity of normal LD-B4 as an index, we could ascertain the proportion of free antigen (LD-B4) and antibody-antigen complexes (LD-B4-anti-LD-B4) and calculate the apparent equilibrium constant, Keq. Doing so, we found the value for Keq in LD-B subunit deficiency to be smaller than that for normal controls. Evidently the expected competitive reaction takes place. We conclude that heterozygous individuals with LD-B subunit deficiency do indeed produce variant (enzymatically inactive) B subunits of LD.

Antibody Affinity↗

Characteristics of the complex between alkaline phosphatase and immunoglobulin A in human serum.

An abnormal band of alkaline phosphatase (ALP) activity was detected by electrophoresis in the serum of a patient with liver cirrhosis, and was shown to be a complex between ALP and immunoglobulin A (IgA) of the lambda type. Physicochemical studies of ALP in the patient's serum showed properties of liver and bone isozymes. The patient's IgA and its F(ab')2 fragment were prepared by column chromatography, and used in in-vitro reconstitution studies with various ALP isozymes. It was found that only the liver and bone ALP attached to the IgA, while the placental and intestinal ALP did not. The ALP was attached to the F(ab')2 fragment of IgA. It is concluded that this complex is the result of an antibody-antigen reaction. Molecular weights of the two complexes, ALP-IgA and ALP-IgA-F(ab')2, suggest that two molecules of monovalent ALP associated with one molecule of divalent IgA.

Alkaline Phosphatase↗

A polymorphic repetitive-sequence PR1 family. Evidence for meiotic instability.

When EcoRI digests of mouse genomic DNA were subjected to Southern blot analysis with the polymorphic repetitive sequence PR1 as a probe, one satellite-like band of 3.5 X 10(3) base-pairs, designated as PR1 family B, was detected in BALB/c-strain mice, but not in the DDD/1- or MOA-strain mice. Analysis of recombinant phage clones revealed that the repeating unit of the PR1 family B was 13.5 X 10(3) base-pairs long. This family consisted of a tandem array of repeating units and occupied as much as 2% of one BALB/c chromosome. Since the BALB/c-specific PR1 family B is not present in DDD/1 or MOA mice, the unpaired portion of the BALB/c chromosome may be looped out in a synaptonemal complex during meiosis in F1 hybrids of the BALB/c strain with DDD/1 or MOA. To determine the fate of this extra DNA, we examined the genotypes of the F1 hybrid mice and of the segregating populations. Although the PR1 patterns of F1 and most N2 mice are consistent with typical Mendelian inheritance, some N2 progeny showed an abnormal 3.5 X 10(3) base-pair band of unexpectedly reduced intensity. This indicated that the extra DNA of PR1 family B occasionally underwent recombination during meiosis in F1 mice, resulting in its apparent excision. Examination of PstI digests supported this interpretation.

Animals↗

Acute effect of triiodothyronine on the dynamics of thyrotropin release from superfused anterior pituitary cells.

The effects of triiodothyronine (T3) on the dynamics of thyrotropin (TSH) release induced by TSH-releasing hormone (TRH) were examined in the presence or absence of a protein synthesis inhibitor, cycloheximide (CX), in a superfusion system using primarily cultured cells of the rat anterior pituitary gland on microcarrier beads. When the cells were continuously stimulated with TRH (10 nM, 180 min), TSH release occurred in a biphasic manner and the profile of TSH release was characterized by an initial sharp peak (phase I), followed by a lower plateau form phase (phase II). Both phase-I and phase-II releases were significantly suppressed in the presence of T3 (1 ng/ml), which was added to the superfusion medium 1 h before initiation of TRH stimulation. The biphasic nature of the release profile was maintained in the presence of T3, suggesting that the site of the T3 action may be common between phase-I and phase-II release. We have already suggested that phase-I release is protein synthesis-independent and phase-II release protein synthesis-dependent using CX in TRH-stimulated cells. In the presence of CX, phase-I release was not suppressed by T3, while phase-II release was still suppressed by T3. The inability of CX to reverse the T3-induced suppression of phase-II release may be masked by the direct CX effect on phase-II release of TSH. The present study indicates that each component (phase I and phase II) of the biphasic release of TSH induced by TRH stimulation was acutely suppressed by T3 and suggests that the T3 action is mediated through protein synthesis.

Animals↗