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Biomedical subjects

H Yotsumoto

Publications and source records attributed to H Yotsumoto.

At least 55 records · Page 3Linked to original sources
PubMed1987

Leukotriene A4 hydrolase in the human lung. Inactivation of the enzyme with leukotriene A4 isomers.

Leukotriene A4 hydrolase from the human lung was purified to apparent homogeneity. The molecular weight (68,000-71,000), the amino acid composition, and the N-terminal amino acid sequence were similar to those of the human neutrophil enzyme but different from those of human erythrocyte enzyme. The lung enzyme was inactivated by its substrate, leukotriene A4. To elucidate the substrate and the inactivator specificity of this enzyme, we synthesized various geometric and positional isomers of leukotriene A4. 14,15-Leukotriene A4, leukotriene A4 methyl ester, and geometric isomers of leukotriene A4 could not serve as substrates, but they inactivated the enzyme. On the other hand, styrene oxide and (5S)-trans-5,6-oxide-8,10,14-cis-12-trans-eicosatetraenoic acid neither served as substrates nor inactivated the enzyme. These results indicate that whereas allylic epoxide structures of arachidonic acids are responsible for inactivation of the enzyme, the free carboxylic acid, 5,6-oxide, and the tetraene structure with the 7,9-trans-11,14-cis configuration are required as a substrate for leukotriene A4 hydrolase.

Arachidonic Acids↗
PubMed1987

Familial hyper-angiotensin converting enzyme (ACE)-emia: increased production of ACE by monocyte-macrophage.

We report here a familial clustering of elevated serum angiotensin converting enzyme (ACE) levels. The patient was a 58-year-old Japanese female. She had been in excellent health until the age of 45, when she noticed a decrease in visual acuity of her left eye. Despite intensive therapy under the diagnosis of occulusion of the central retinal vein, she lost her visual acuity at the age of 45. Thereafter, she has been in excellent health. The only abnormality found in this case has been a markedly elevated level of serum ACE (625 n mol/min/ml; normal range; 22-40 n mol/min/ml of serum). Her blood pressure was within normal limits (140/80 mmHg). There was no evidence for the diagnosis of sarcoidosis, Gaucher's disease, leprosy, hyperthyroidism, diabetic retinopathy, or liver disease. One of her two sisters also showed a marked increase in serum ACE activity (303 n mol/min/ml), and remarkably high levels of serum ACE (276 and 294 n mol/min/ml) were demonstrated in both of two sons of this sister. All the members of this family have been in excellent health. The serum ACE activity was activated by chloride and cobalt ions, and inhibited by EDTA, captopril and rabbit antiserum to purified human plasma ACE. Thus, our study showed a familial clustering of "hyper-ACE-emia", and the disorder appears to have been inherited as an autosomal dominant trait.

Cells, Cultured↗
PubMed1987

Primary pulmonary lymphoma demonstration of monoclonality by lymphocyte surface marker study.

We present here a case of small lymphocytic B cell lymphoma of the lung which developed in a 51-year-old Japanese man who was asymptomatic while his chest X-rays revealed slowly progressive infiltrative shadows. Findings of transbronchial lung biopsy suggested lymphoproliferative disorders and the diagnosis of B-cell lymphoma of the lung was established with lung specimen obtained by an open lung biopsy and through demonstration of monoclonal surface markers on lymphocytes in fresh frozen lung sections. Diagnostic value of surface marker analysis is emphasized.

Antibodies, Monoclonal↗
PubMed1986

Increase of serum angiotensin-converting enzyme level after exposure to cigarette smoke and nicotine infusion in dogs.

Smoking is known to have various effects on metabolic function as well as on the respiratory function in the lung. We report here that exposure to smoke causes a rapid elevation of the level of serum angiotensin-converting enzyme in dogs in vivo. In 7 dogs, the level of serum angiotensin-converting enzyme increased from a basal level of 11.0 +/- 5.0 to 13.9 +/- 4.0 U/ml after 60 min of exposure (mean +/- SD, p less than 0.01). A similar elevation of serum angiotensin-converting enzyme level was noted in dogs that received an intravenous administration of nicotine. The possible mechanism of the change is discussed.

Animals↗
PubMed1985

Angiotensin-converting enzyme from human tissues. Physicochemical, catalytic, and immunological properties.

Angiotensin-converting enzyme was purified from human lung, kidney, testis, blood plasma, and seminal plasma using a facile two-step protocol which included affinity chromatography on Sepharose-bound lisinopril followed by either gel filtration or hydroxylapatite chromatography. Molecular mass for converting enzyme from all sources except testis was 140 kDa. That from testis consisted of both a 90- and a 140-kDa form in a 4:1 ratio. Detergent-extracted membrane-bound converting enzyme aggregated on gel filtration chromatography, while trypsin-extracted and soluble converting enzyme did not. Comparison of detergent-extracted and trypsin-extracted membrane-bound converting enzyme by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and isoelectric focusing indicated that the membrane binding sequence contributed minimally to the size and charge of the enzyme. Catalytic and kinetic properties assessed by interaction with substrates, inhibitors, and anti-converting enzyme immunoglobulin were similar for all forms and sources of converting enzyme. Enzyme-linked immunosorbent assay revealed only partial homology between the 90- and 140-kDa forms of the enzyme.

Chromatography, Gel↗
PubMed1985

Familial elevation of serum angiotensin converting enzyme.

We report here a familial clustering of elevated serum angiotensin converting enzyme (ACE) levels. The patient is a 58-year-old Japanese female who had been in excellent health until age 45 when she developed an occlusion of the left central retinal vein. She was otherwise in excellent health, and no laboratory abnormality except a marked elevation of serum ACE level (625 nmol/min/ml; normal range; 22-40 nmol/min/ml of serum) was found. Her blood pressure was within normal limits (140/80 mmHg). There was no evidence for the diagnosis of sarcoidosis, Gaucher's disease, leprosy, hyperthyroidism, diabetic retinopathy, or liver disease. One of her two sisters also showed a marked increase in serum ACE activity (303 nmol/min/ml), and remarkably high levels of serum ACE (276 and 294 nmol/min/ml) were demonstrated in both sons of this sister. All the members of this family have been in excellent health. The serum ACE activity was activated by chloride and cobalt ions, and inhibited by EDTA, captopril and rabbit antiserum to purified human plasma ACE. Thus our study showed a familial clustering of elevated serum ACE in individuals who did not have conventional disease patterns associated with elevated serum ACE.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1984

Localization of angiotensin converting enzyme (dipeptidyl carboxypeptidase) in swine sperm by immunofluorescence.

Testis and epididymis are known to have high amounts of angiotensin converting enzyme (dipeptidyl carboxypeptidase, EC 3.4.15.1). We investigated the localization of the enzyme in these tissues by an immunofluorescent technique and found that the enzyme was localized in the spermatids and residual bodies in the Sertoli cells of the testis. Furthermore, the enzyme was shown to be present in the cytoplasmic droplet of epididymal sperm and also in detached cytoplasmic droplets in semen. The enzyme was not detected in the interstitium of testis and epididymis except for the endothelial cells of the vessel.

Acrosome↗
PubMed1983

Generation of a 90 000 molecular weight fragment from human plasma angiotensin-I-converting enzyme by enzymatic or alkaline hydrolysis.

A catalytically active Mr 90 000 fragment was generated from native Mr 140 000 human plasma angiotensin-I-converting enzyme after treatment with reagents that induced a perturbation of the native tertiary conformation. Treatment of converting enzyme with 6 M urea produced an aggregation of molecules that was susceptible to proteolysis by either trypsin, chymotrypsin or Staphylococcus aureus V8 proteinase to generate the Mr 90 000 converting enzyme. Also, 1 M ammonium hydroxide, pH 11.3, or 0.01 M sodium hydroxide, pH 11.3, cleaved converting enzyme to the Mr 90 000 fragment. Degradation was not an autocatalytic phenomenon, since it was not prevented by inhibition of converting enzyme with EDTA. The enzymatically mediated, but not the alkaline mediated, cleavage was inhibited by specific converting enzyme inhibitors captopril and Merck L-154,826. This suggests that captopril and Merck L-154,826 can prevent converting-enzyme degradation by preserving a conformation that does not have sites exposed to proteolytic enzymes. This conformation may mimic the native conformation which is quite resistant to serine proteinases.

Humans↗