Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 312
Filter
2.
Phys Rev Lett ; 111(6): 067601, 2013 Aug 09.
Article in English | MEDLINE | ID: mdl-23971612

ABSTRACT

We report the detection and polarization of nuclear spins in diamond at room temperature by using a single nitrogen-vacancy (NV) center. We use Hartmann-Hahn double resonance to coherently enhance the signal from a single nuclear spin while decoupling from the noisy spin bath, which otherwise limits the detection sensitivity. As a proof of principle, we (i) observe coherent oscillations between the NV center and a weakly coupled nuclear spin and (ii) demonstrate nuclear-bath cooling, which prolongs the coherence time of the NV sensor by more than a factor of 5. Our results provide a route to nanometer scale magnetic resonance imaging and novel quantum information processing protocols.


Subject(s)
Magnetic Resonance Spectroscopy , Models, Theoretical , Nuclear Physics/methods , Electrons , Nitrogen/chemistry
3.
Respir Physiol Neurobiol ; 161(1): 69-75, 2008 Mar 20.
Article in English | MEDLINE | ID: mdl-18243069

ABSTRACT

To clarify the mechanism of action of aminophylline on the hypoxic ventilatory response in humans, we analyzed the effects of aminophylline on respiratory neural output. To evaluate the respiratory neural output, we analyzed the electromyogram (EMG) of the parasternal intercostal muscle, one of the major inspiratory muscles, in eight healthy subjects. Both before and during aminophylline administration, measurements of ventilatory parameters with EMG recordings were conducted in room air, mild hypoxia (F(I)(o)(2) 0.15), and severe hypoxia (F(I)(o)(2) 0.11). Before administering aminophylline, hypoxic stimulation elicited ventilatory augmentation in a hypoxia-intensity dependent manner. Administration of aminophylline caused significant increases in ventilation (V (I)), tidal volume (V(T)), respiratory frequency (f(R)), and the respiration-related phasic moving averaged EMG amplitude (tidal EMG), at corresponding levels of hypoxia compared to before aminophylline. Augmentation patterns of hypoxia-induced increases in V(T) and tidal EMG showed close similarity. These results indicate that augmentation of hypoxic ventilatory response by aminophylline is mainly mediated by an increase in the respiratory neural drive in healthy humans.


Subject(s)
Aminophylline/pharmacology , Bronchodilator Agents/pharmacology , Hypoxia/drug therapy , Intercostal Muscles/drug effects , Adult , Electromyography , Humans , Intercostal Muscles/innervation , Male , Pulmonary Ventilation/drug effects , Respiratory Function Tests , Tidal Volume/drug effects
4.
Respir Physiol Neurobiol ; 161(3): 253-60, 2008 May 31.
Article in English | MEDLINE | ID: mdl-18434261

ABSTRACT

The effect of the beta-agonist bronchodilator salbutamol on respiratory muscles and ventilation is uncertain. The presence of beta2 receptors on skeletal muscles and increased diaphragm contractility in vitro with salbutamol predict a significant effect that has not been confirmed, in vivo in non-fatigued diaphragm or in clinical studies using standard bronchodilator dosages. Therefore, we infused salbutamol at a higher dosage (23.3 microg/min) used clinically for treatment of respiratory emergencies, while measuring directly the length, shortening and EMG activation of costal and crural diaphragm, parasternal intercostal and transversus abdominis muscles, in 10 awake canines. At this salbutamol dosage, ventilation and tidal volume increased significantly during both resting and CO2-stimulated breathing. Salbutamol elicited significant increases in respiratory muscle shortening with much smaller increases in EMG activity, so the proportionally greater muscle shortening per unit EMG showed increased muscle contractility. The effects of salbutamol were not extinguished by inspiratory flow resistance or fluid challenge but were reversed specifically by the beta-blocker, propranolol. This study demonstrates that, in sufficient intravenous dosage, the beta-agonist salbutamol elicits increased ventilation and a beta2 receptor-mediated increase in contractility of respiratory muscles.


Subject(s)
Albuterol/pharmacology , Bronchodilator Agents/pharmacology , Respiratory Muscles/drug effects , Respiratory Physiological Phenomena/drug effects , Wakefulness , Animals , Dogs , Dose-Response Relationship, Drug , Electromyography , Hypercapnia/physiopathology , Tidal Volume/drug effects , Tidal Volume/physiology
5.
Cancer Res ; 58(2): 296-301, 1998 Jan 15.
Article in English | MEDLINE | ID: mdl-9443408

ABSTRACT

Tyrosinase is an antigen that is expressed by normal melanocytes as well as melanoma cells, against which responses by autologous T cells have been detected. Although CD4+ T cells play an important role in tumor immunity in animal tumor models, little information about CD4+ T-cell immunity against human tumors exists. Here, we report that CD4+ T cells from the peripheral blood of a patient with melanoma respond to synthetic peptides derived from nonmutated tyrosinase. T-cell clones were generated that recognized the tyrosinase p386-406 peptide when it was presented by the HLA-DR15 (DRB1*1501) molecule. The CD4+ T-cell clone also recognized autologous EBV-transformed B-lymphoblastoid cell lines that had been pulsed with the lysate of melanoma cells. The synthetic tyrosinase p386-406 peptide was capable of binding to HLA-DR15 (DRB1*1501) molecules on cell surface of DR15 homozygous cells. Thus, the finding that nonmutated tyrosinase peptides are immunogenic in a melanoma patient may provide the basis for the development of cancer immunotherapy, based on knowledge of synthetic tumor-associated peptide antigens.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , HLA-DR Antigens/immunology , Melanoma/blood , Monophenol Monooxygenase/immunology , Peptide Fragments/immunology , Skin Neoplasms/blood , Antigen-Presenting Cells , Antigens, Neoplasm/immunology , Antigens, Neoplasm/metabolism , CD4-Positive T-Lymphocytes/drug effects , Cell Line, Transformed , Cell-Free System/drug effects , Clone Cells , Cytokines/analysis , Enzyme-Linked Immunosorbent Assay , HLA-DR Antigens/metabolism , HLA-DR Serological Subtypes , Herpesvirus 4, Human , Humans , Monophenol Monooxygenase/chemistry , Monophenol Monooxygenase/genetics , Peptide Fragments/metabolism , Protein Binding
6.
Biochim Biophys Acta ; 657(2): 530-4, 1981 Feb 13.
Article in English | MEDLINE | ID: mdl-7213760

ABSTRACT

Salicylate hydroxylase (salicylate, NADH: oxygen oxidoreductase (1-hydroxylating, decarboxylating), EC 1.14.13.1) in Pseudomonas putida catalyzed hydroxylation of the substrate analogue, salicylaldehyde, to form catechol and formate with stoichiometric consumption of NADH and O2. Consequently, a study of primary product derived from the carboxyl group of the authentic substrate, salicylate, was undertaken. The experimental results revealed that CO2 not H2CO3, was produced first.


Subject(s)
Mixed Function Oxygenases/metabolism , Pseudomonas/enzymology , Aerobiosis , Aldehydes , Anaerobiosis , Kinetics , Salicylates/metabolism , Substrate Specificity
7.
J Bone Miner Res ; 15(4): 674-82, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10780859

ABSTRACT

In the search for a new class of bone-sparing agents, we have conducted random screening of the domestic chemical library using 45Ca release assay from prelabeled cultured neonatal mouse calvariae and identified a novel synthetic triazolotriazepine JTT-606 as a candidate for a potent inhibitor of bone resorption. JTT-606 inhibited 45Ca release dose dependently not only in the control calvarial culture but also in the stimulated cultures by interleukin-1alpha (IL-1alpha), fibroblast growth factor 2 (FGF-2), and parathyroid hormone (PTH). JTT-606 also inhibited both basal and stimulated osteoclast-like (OCL) cell formation in the coculture of mouse osteoblastic cells and bone marrow cells dose dependently, indicating its inhibitory effect on osteoclast differentiation. Ex vivo OCL cell formation by cultured bone marrow cells collected from ovariectomized (OVX) mice also was decreased dose dependently by in vivo application of JTT-606 to a level similar to that from sham-operated mice. Furthermore, JTT-606 inhibited resorbed pit formation by isolated mature osteoclasts as well as by unfractionated bone cells derived from rabbit long bones in the control and FGF-2-stimulated cultures dose dependently, indicating both the direct and the indirect actions of JTT-606 on mature osteoclast function. In addition, JTT-606 reduced production of IL-1alpha, tumor necrosis factor alpha (TNF-alpha), IL-6, and granulocyte-macrophage colony-stimulating factor (GM-CSF) in the human peripheral blood mononuclear cell culture. In vivo analyses of mature OVX rats revealed that the application of JTT-606 for 12 weeks increased the BMD of the lumbar spine and decreased the levels of serum osteocalcin and urine deoxypyridinoline to levels similar to those of 17beta-estradiol-treated OVX rats. We propose that JTT-606 may inhibit both osteoclast differentiation and function by down-regulating both the action and the production of bone resorptive factors. It is speculated that JTT-606 could be a potent agent for the treatment of osteopenic disorders with elevated osteoclastic bone resorption.


Subject(s)
Bone Resorption/physiopathology , Down-Regulation , Fibroblast Growth Factor 2/metabolism , Interleukin-1/metabolism , Parathyroid Hormone/metabolism , Pyridines/pharmacology , Animals , Azulenes , Bone Density/drug effects , Calcium Radioisotopes/metabolism , Cell Differentiation , Cells, Cultured , Culture Techniques , Female , Fibroblast Growth Factor 2/pharmacology , Granulocyte-Macrophage Colony-Stimulating Factor/biosynthesis , Humans , Interleukin-1/pharmacology , Interleukin-6/biosynthesis , Mice , Osteoclasts/classification , Osteoclasts/drug effects , Osteoclasts/physiology , Ovariectomy , Parathyroid Hormone/pharmacology , Rabbits , Rats , Rats, Inbred F344 , Skull , Tibia/drug effects , Tumor Necrosis Factor-alpha/biosynthesis
8.
J Bone Miner Res ; 16(11): 2074-81, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11697804

ABSTRACT

This study investigated the mechanism of direct and indirect actions of fibroblast growth factor 2 (FGF-2) on osteoclast differentiation using two mouse cell culture systems. In the coculture system of osteoblasts and bone marrow cells, FGF-2 stimulated osteoclast formation. This effect was decreased markedly by osteoprotegerin (OPG) or NS-398, a selective cyclo-oxygenase 2 (COX-2) inhibitor. FGF-2 (> or = 10(-9) M) stimulated receptor activator of nuclear factor kappaB ligand/osteoclast differentiation factor (RANKL/ODF) messenger RNA (mRNA) expression from 2 h to 7 days in cultured osteoblasts. NS-398 did not affect the early induction but decreased the later one, indicating that the later effect is mediated by COX-2 induction in osteoblasts. To study the direct action of FGF-2 on osteoclast precursors, we used mouse macrophage-like cell line C7 cells that can differentiate into osteoclasts in the presence of soluble RANKL/ODF (sRANKL/ODF) and macrophage colony-stimulating factor (M-CSF). Although osteoblasts expressed all FGF receptors (FGFR-1 to -4), only FGFR-1 was detected in C7 cells at various differentiation stages. FGF-2 alone or in combination with sRANKL/ODF did not induce osteoclastogenesis from C7 cells; however, FGF-2 from lower concentrations (> or = 10(-11) M) significantly decreased osteoclast formation induced by M-CSF in the presence of sRANKL/ODF. FGF-2 did not alter mRNA levels of M-CSF receptor (Fms) or RANK in C7 cells. Immunoprecipitation/ immunoblotting analyses revealed that tyrosine phosphorylation of several cellular proteins including Fms in C7 cells induced by M-CSF was inhibited by FGF-2 in the presence of sRANKL/ODF. We conclude that FGF-2 regulates osteoclast differentiation through two different mechanisms: (1) an indirect stimulatory action via osteoblasts to induce RANKL/ODF partly through COX-2 induction and prostaglandin production and (2) a direct inhibitory action on osteoclast precursors by counteracting M-CSF signaling.


Subject(s)
Carrier Proteins/metabolism , Fibroblast Growth Factor 2/pharmacology , Macrophage Colony-Stimulating Factor/metabolism , Membrane Glycoproteins/metabolism , Osteoblasts/drug effects , Osteoblasts/metabolism , Osteoclasts/cytology , Osteoclasts/drug effects , Animals , Bone Remodeling/genetics , Bone Remodeling/physiology , Carrier Proteins/genetics , Cell Differentiation/drug effects , Cell Line , Cyclooxygenase 2 , Gene Expression/drug effects , Glycoproteins/genetics , Isoenzymes/genetics , Isoenzymes/metabolism , Membrane Glycoproteins/genetics , Mice , Osteoclasts/metabolism , Osteoprotegerin , Prostaglandin-Endoperoxide Synthases/genetics , Prostaglandin-Endoperoxide Synthases/metabolism , RANK Ligand , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptor Activator of Nuclear Factor-kappa B , Receptor Protein-Tyrosine Kinases/genetics , Receptor, Fibroblast Growth Factor, Type 1 , Receptors, Cytoplasmic and Nuclear/genetics , Receptors, Fibroblast Growth Factor/genetics , Receptors, Tumor Necrosis Factor , Stem Cells/cytology , Stem Cells/drug effects , Stem Cells/metabolism
9.
Am J Surg Pathol ; 18(8): 832-6, 1994 Aug.
Article in English | MEDLINE | ID: mdl-8037297

ABSTRACT

We report an apocrine adenocarcinoma of the left axilla associated with hamartomatous apocrine gland hyperplasia of both axillae. The patient, a 69-year-old man, presented with no symptoms or complaints other than an oval mass felt in the left axilla. The mass was resected and histopathological examination revealed a papillary apocrine adenocarcinoma located within hyperplastic apocrine glands. Because gallium scintigraphy performed after the operation still showed bilateral abnormal uptakes, skin and subcutaneous tissues of the bilateral axillary areas were resected. Histological examination demonstrated marked multilobular hyperplasia of the apocrine glands. These hyperplastic glands did not show distinct atypia, and there was no evidence of tumor remnants in the left axilla. The patient has shown no signs of local recurrence or metastasis at 20 months' follow-up. To our knowledge, this is the first case of malignant transformation of hamartomatous apocrine gland hyperplasia (apocrine gland organic hamartoma or apocrine nevus).


Subject(s)
Adenocarcinoma/etiology , Apocrine Glands/pathology , Hamartoma/complications , Sweat Gland Neoplasms/etiology , Adenocarcinoma/pathology , Aged , Axilla , Hamartoma/pathology , Humans , Hyperplasia/complications , Male , Sweat Gland Diseases/complications , Sweat Gland Diseases/pathology , Sweat Gland Neoplasms/pathology
10.
Transplantation ; 20(2): 135-41, 1975 Aug.
Article in English | MEDLINE | ID: mdl-1179475

ABSTRACT

Papain solubilization of rat Ag-B histocompatibility antigens produces Ag-B molecules of about 59,000 daltons which have been shown to contain two fragments bound noncovalently: one fragment about 37,000 daltons carrying Ag-B allospecificity, and another about 11,000 daltons, an apparent rat homologue of human beta2-microglobulin. Beside the 59,000-dalton Ag-B molecules, papain digests of liver cell membranes of ACI strain rats were found to contain Ag-B molecules of about 25,000 and 35,000 daltons. These smaller Ag-B molecules carried Ag-B private specificity of the rat strain (i.e., Ag-B4), as did the 59,000-dalton Ag-B molecules, and accounted for 40% of the solubilized Ag-B alloantigenic activity. The smaller Ag-B molecules were tested for the antigenic specificities that are characteristic of each of the two fragments of the 59,000-dalton molecules and detected by rabbit antiserum against rat cell membranes. The 35,000-dalton Ag-B molecules were found to contain the Ag-B 11,000-dalton fragment (i.e., rat beta2-microglobulin homologue) and to differ from the 59,000-dalton Ag-B molecules only in absence of a part of the 37,000-dalton fragment portion. The 25,000-dalton Ag-B molecules did not contain the rat beta2-microglobulin homologue and contained only a single component that is similar to the alloantigenic fragment portion of the 35,000-dalton Ag-B molecules. Similar 25,000-dalton Ag-B molecules (carrying Ag-B1 private specificity) of a single component were found in Fischer rat material. They accounted for 10% of the solubilized Ag-B alloantigenic activity.


Subject(s)
Histocompatibility Antigens/isolation & purification , Papain , Animals , Cell Membrane/immunology , Chemical Fractionation , Chromatography, Gel , Immune Sera , Liver/cytology , Molecular Weight , Rabbits/immunology , Radioimmunoassay , Rats , Rats, Inbred ACI , Rats, Inbred F344
11.
Transplantation ; 19(3): 230-9, 1975 Mar.
Article in English | MEDLINE | ID: mdl-1138446

ABSTRACT

Ag-B antigen molecules of about 59,000 daltons were partially purified from papain digests of liver cell membranes of Fischer and ACI rats. These preparations were radioiodinated and the labeled Ag-B antigen molecultes were isolated as specific immune complexes with alloantibodies directed to Ag-B1 or Ag-B4. These specifically purified Ag-B antigen molecules were found to give two fragments of 37,000 and 11,000 daltons on sodium sulfate-acrylamide gel electrophoresis. The two fragments (or very similar ones) were isolated from the radioiodinated partially purified Ag-B antigen preparations by acid dissociation and subsequent gel filtration. The 37,000-dalton fragment retained the same Ag-B alloantigenic specificity as the parental 59,000-dalton Ag-B antigen molecules, whereas the 11,000-dalton fragment did not carry any detectable Ag-B alloantigenic activity. In the reaction with rabbit antisera raised against rat cell membranes, each fragment was shown to be antigenically distinctive.


Subject(s)
Histocompatibility Antigens/isolation & purification , Papain , Rats/immunology , Animals , Antibody Specificity , Antigen-Antibody Complex , Cell Membrane/immunology , Electrophoresis, Polyacrylamide Gel , Hemagglutination Tests , Immune Sera , Iodine Radioisotopes , Isoantibodies , Liver/cytology , Radioimmunoassay , Rats, Inbred Strains , Sodium Dodecyl Sulfate
12.
Hum Immunol ; 14(4): 379-90, 1985 Dec.
Article in English | MEDLINE | ID: mdl-2416721

ABSTRACT

The la subset that reacts with alloantiserum HON known to possess a strong anti-DRw53 activity was isolated from a 125I-labeled Ia preparation obtained from cells of RPMI 8057 cell line (DR1,4) and was found on peptide mapping to be lacking in the pattern characteristic of DR-like molecules carrying the DRw53 specificity and to display the structural features of DQ molecules, particularly those carrying the DQw3 specificity. Distribution analysis on a panel of selected la-positive cell lines indicated that the specificity involved is associated only with DR4 and DRw9, differing from the known DRw53 pattern (DR4, 7, and w9) and also from the known DQw3 pattern (DR4 and 5). Reciprocal sequential binding experiments demonstrated that the HON-defined specificity resides along with DQw3 specificity on the same molecules. Thus, HON alloantiserum possesses two different antibody activities; one directed to DRw53 specificity and another directed to a new DR4- and w9-associated DQ specificity.


Subject(s)
Epitopes/analysis , HLA-DR Antigens , Histocompatibility Antigens Class II/immunology , Isoantibodies/immunology , HLA-DQ Antigens , HLA-DR Serological Subtypes , HLA-DR4 Antigen , Histocompatibility Antigens Class II/analysis , Isoantigens/immunology
13.
Hum Immunol ; 1(4): 357-62, 1980 Dec.
Article in English | MEDLINE | ID: mdl-6973561

ABSTRACT

Sixty-four Japanese insulin dependent juvenile onset diabetes mellitus (JOD) were studied in relation to HLA-A, B, and DR. Significant deviations were observed. HLA-Bw54 was increased (PF = 49.2%, RR = 6.4) and HLA-B5 was decreased (PF = 7.9%, RR = 0.19). Using radioimmunoassay, two HLA-DR antigens were investigated. Hon 7 antigen, so-called MT3 (WIA4x7), which has linkage disequilibrium between HLA-BW54, is highly associated (PF = 96.9%, RR = 27.8) with JOD found in the Japanese.


Subject(s)
B-Lymphocytes/immunology , Diabetes Mellitus, Type 1/immunology , Isoantigens , Adolescent , Adult , Diabetes Mellitus, Type 1/genetics , Genetic Linkage , HLA Antigens , Histocompatibility Testing , Humans , Japan , Radioimmunoassay
14.
Hum Immunol ; 5(2): 123-32, 1982 Oct.
Article in English | MEDLINE | ID: mdl-6815137

ABSTRACT

Japanese patients with rheumatoid arthritis (RA) were observed to have a statistical association with HLA-DR4, MT3. Strong association between the clinical severity of RA and HLA was also observed. Male patients had a stronger association with HLA than female patients. Males are more resistant to RA than females. This suggested that the threshold of liability for RA is higher in males than in females. Japanese patients with RA with systemic vasculitis were negative for HLA-Bw44 and had antilymphocytotoxic autoantibody, indicating that RA with systemic vasculitis is different in etiology from RA without systemic vasculitis.


Subject(s)
Arthritis, Rheumatoid/genetics , Genes, MHC Class II , HLA Antigens/genetics , Adult , Female , Gene Frequency , Humans , Japan , Male , Mathematics , Phenotype
15.
Aliment Pharmacol Ther ; 10(5): 821-7, 1996 Oct.
Article in English | MEDLINE | ID: mdl-8899093

ABSTRACT

AIM: The effect of lansoprazole plus amoxycillin on curing Helicobacter pylori infection and peptic ulcer recurrence was evaluated. METHOD: The study group was composed of 68 patients with gastric ulcers and 51 with duodenal ulcers, all were H. pylori-positive. The participants were assigned at random to the lansoprazole alone group (lansoprazole 30 mg o.m. for 6 or 8 weeks) or the lansoprazole plus amoxycillin group (lansoprazole alone regimen plus amoxycillin at 500 mg q.d.s. concomitantly for the first 2 weeks). Healed patients were not given maintenance treatment with acid secretion inhibitors. The cure rate for H. pylori infection and the ulcer recurrence rate after 1 year were investigated. RESULT: The cure rate for H. pylori infection was 4.2% in patients receiving lansoprazole alone and 38.5% in patients receiving lansoprazole plus amoxycillin (P < 0.01) for gastric ulcers, and 0% in patients receiving lansoprazole alone and 61.9% in patients receiving lansoprazole plus amoxycillin (P < 0.001) for duodenal ulcers. The recurrence rate was 42.3% in patients receiving lansoprazole alone and 28.6% in patients receiving lansoprazole plus amoxycillin for gastric ulcers, and 66.7% for patients receiving lansoprazole alone and 11.1% for patients receiving lansoprazole plus amoxycillin (P < 0.001) for duodenal ulcers. None of the patients with gastric or duodenal ulcers cured of H. pylori infection had a recurrence. CONCLUSION: Concomitant use of lansoprazole and amoxycillin increased the curative effects on H. pylori infection. However, the cure rates with this regimen remained inadequate.


Subject(s)
Amoxicillin/therapeutic use , Anti-Ulcer Agents/therapeutic use , Helicobacter Infections/drug therapy , Omeprazole/analogs & derivatives , Penicillins/therapeutic use , 2-Pyridinylmethylsulfinylbenzimidazoles , Administration, Oral , Adult , Aged , Amoxicillin/administration & dosage , Amoxicillin/pharmacology , Anti-Ulcer Agents/administration & dosage , Anti-Ulcer Agents/pharmacology , Drug Synergism , Duodenal Ulcer/drug therapy , Female , Helicobacter pylori/drug effects , Helicobacter pylori/metabolism , Humans , Japan , Lansoprazole , Male , Middle Aged , Omeprazole/administration & dosage , Omeprazole/pharmacology , Omeprazole/therapeutic use , Penicillins/administration & dosage , Penicillins/pharmacology , Recurrence , Stomach Ulcer/drug therapy
16.
J Biochem ; 100(4): 945-54, 1986 Oct.
Article in English | MEDLINE | ID: mdl-3029050

ABSTRACT

The nucleotide sequence of the mRNA for NADPH-cytochrome P-450 reductase from rabbit liver was determined from a full-length cDNA clone (pFP105). The clone contains 2,269 nucleotides complementary to rabbit liver reductase mRNA. The single open reading frame of 2,037 nucleotides codes for a 679-amino acid polypeptide with a calculated molecular weight of 76,583 daltons. The cloned cDNA contains the complete 3'-noncoding region of 193 nucleotides, including 68 nucleotides of poly(A), and 39 nucleotides of the 5'-noncoding region. The nucleotide sequence in the coding region of cDNA of rabbit reductase (pFP105) showed 85% homology to that of rat reductase (Porter, T.D. & Kasper, C.B. (1985) Proc. Natl. Acad. Sci. U.S. 82, 973-977, and Murakami, H. et al. (1986) DNA 5, 1-10). Rabbit reductase has one more amino acid residue than the rat enzyme, and the amino acid compositions of the two enzymes are similar. The amino acid sequence of the rabbit enzyme showed 91% identity with that of the rat enzyme. The segment related to binding of FMN and FAD was well conserved among rabbit, rat, and pig reductases. The sequence related to AMP moiety-binding was also conserved among these species, and was found in the amino acid sequence of NADH-cytochrome b5 reductase, another flavoenzyme in the microsomal electron transport system.


Subject(s)
Cloning, Molecular , DNA/metabolism , Genes , Liver/enzymology , NADPH-Ferrihemoprotein Reductase/genetics , RNA, Messenger/genetics , Amino Acid Sequence , Animals , Base Sequence , DNA Restriction Enzymes , Male , Molecular Weight , Nucleic Acid Hybridization , Rabbits
17.
J Steroid Biochem Mol Biol ; 42(1): 95-101, 1992 Mar.
Article in English | MEDLINE | ID: mdl-1558822

ABSTRACT

The minor steroid hydroxylase activity of purified bovine adrenocortical mitochondrial P-450 is described. The results indicate that both P-450scc and P-450(11 beta) act on deoxycorticosterone and androstenedione to form 6 beta-hydroxydeoxycorticosterone and 6 beta-hydroxyandrostenedione (6 beta-hydroxylase), respectively. Both forms of P-450 also catalyze 6-desaturation of androstenedione to form 4,6-androstadiene-3,17-dione (6-desaturase).


Subject(s)
Adrenal Cortex/enzymology , Cytochrome P-450 Enzyme System/metabolism , Mitochondria/enzymology , Steroid Hydroxylases/metabolism , Adrenal Cortex/ultrastructure , Androstenedione/metabolism , Animals , Cattle , Cholesterol Side-Chain Cleavage Enzyme/metabolism , Chromatography, High Pressure Liquid , Desoxycorticosterone/metabolism , Gas Chromatography-Mass Spectrometry , Oxidoreductases/metabolism , Steroid 11-beta-Hydroxylase/metabolism
18.
J Steroid Biochem Mol Biol ; 37(1): 133-6, 1990 Sep.
Article in English | MEDLINE | ID: mdl-2242347

ABSTRACT

Purified bovine P-450scc, the cholesterol side-chain cleaving P-450 in adrenal cortex mitochondria, was found to catalyze a deoxycorticosterone 6 beta-hydroxylase reaction. A turnover number (moles of product formed/min/mol of P-450) of 12 was found similar to that for cholesterol side chain cleavage activity. Conversion was dose-dependent in terms of P-450scc and no reaction took place when any one of the required electron donating components such as NADPH, NADPH-adrenodoxin reductase, or adrenodoxin was omitted. These results confirm and extend earlier observations that 21-hydroxypregnenolone is transformed into both deoxycorticosterone and 6 beta-hydroxydeoxycorticosterone by incubation of adrenal gland slices.


Subject(s)
Adrenal Cortex/enzymology , Cytochrome P-450 Enzyme System/metabolism , Desoxycorticosterone/metabolism , Mitochondria/enzymology , Mixed Function Oxygenases/metabolism , Adrenodoxin/metabolism , Animals , Cattle , Chromatography, High Pressure Liquid , NADP/metabolism
19.
J Steroid Biochem Mol Biol ; 38(4): 533-5, 1991 Apr.
Article in English | MEDLINE | ID: mdl-2031867

ABSTRACT

Adrenal P-450 activities were measured by an in vitro reconstitution system from tissues obtained from human aldosteronomata, and the results compared with those of the normal adrenal tissues from patients with Grawitz's tumor. The P-45011 beta activity was significantly increased in adenoma tissue (55.6 +/- 5.3 vs 9.0 +/- 6.2 nmol corticosterone/mg of protein/min in the control tissues, P less than 0.01). P-450scc activity in adrenal adenomata was 13.4 +/- 2.0 nmol pregnenolone/mg of protein/min, significantly higher than control (P less than 0.05). The present results suggest that increased mitochondrial P-450(11 beta) activities may be characteristic of aldosterone-producing adenomata.


Subject(s)
Adenoma/enzymology , Adrenal Gland Neoplasms/enzymology , Adrenal Glands/enzymology , Cytochrome P-450 Enzyme System/metabolism , Mitochondria/enzymology , Carcinoma, Renal Cell/enzymology , Humans , Hyperaldosteronism/enzymology , Kidney Neoplasms/enzymology
20.
J Steroid Biochem Mol Biol ; 64(1-2): 121-8, 1998 Jan.
Article in English | MEDLINE | ID: mdl-9569017

ABSTRACT

Steroid hydroxylase cytochrome P450c17 has been previously purified from microsomal fractions of immature rat livers. In this study, we investigated the expression of P450c17 in rat livers to understand a role of steroidogenesis in the extrasteroidogenic tissue. Upon immunoblot analysis utilizing liver microsomes from rats, P450c17 was detected in 1 and 3 week old rats but not in adult rats. Data from immunohistochemical studies also showed a similar age-dependent expression of P450c17 and indicated that P450c17 detected in immature rat livers is localized in cells surrounding interlobular veins. This age-dependent expression of P450c17 in rat livers was observed in both sexes. Upon enzymatic analysis utilizing microsomal fractions from livers, levels of 17alpha-hydroxylase and 17,20-lyase activity for pregnenolone and progesterone increased by 3 weeks and dramatically reduced at 7 weeks, which is consistent with the expression level of P450c17. These data clearly indicate that P450c17 is expressed in immature rat liver to produce 17alpha-hydroxysteroids and C19-steroids. Based upon immunoblot analysis, the expression level of P450c17 in immature rat livers was approximately one third of that in testis. Compared expression level of P450c17 and total volume of organs between liver and testis, the total amount of steroid metabolites produced by liver P450c17 could be greater than that produced by gonadal P450c17. Because of the absence of P450c17 in rat adrenal glands, rat liver could be the major site for producing 17alpha-hydroxysteroids and C19-steroids in this particular period of life. Although physiological products formed by P450c17 in liver and their roles remain to be elucidated, this study suggests a large capacity of prepubertal rat liver for participating the production of steroid hormones and a putative importance of 17alpha-hydroxysteroids and C19-steroids, such as cortisol and androstendione, which are generally believed to be minor components of steroid hormones in rodents.


Subject(s)
Liver/metabolism , Steroid 17-alpha-Hydroxylase/metabolism , Steroids/biosynthesis , Animals , Base Sequence , DNA Primers/genetics , Female , Gene Expression Regulation, Developmental , Gene Expression Regulation, Enzymologic , Immunohistochemistry , Liver/enzymology , Liver/growth & development , Male , Microsomes, Liver/enzymology , Polymerase Chain Reaction , Pregnenolone/metabolism , Progesterone/metabolism , Rats , Rats, Wistar , Steroid 17-alpha-Hydroxylase/genetics , Testis/enzymology
SELECTION OF CITATIONS
SEARCH DETAIL