PubMed Health⌕ Search

Biomedical subjects

F Wada

Publications and source records attributed to F Wada.

At least 73 records · Page 4Linked to original sources
PubMed1978

[Spectral studies of drug interactions with hemoglobin and cytochrome c (author's transl)].

We studied the drug-induced spectra of hemoglobin and cytochrome c using aniline, aminopyrine, hydrocortisone and prednisolone. The difference spectrum of methemoglobin induced by aniline or aminopyrine was similar to type II, and that of oxidized cytochrome c induced by aniline was similar to type I. Characteristic spectral change occurred with addition of hydrocortisone or prednisolone to each of methemoglobin, oxyhemoglobin and carboxyhemoglobin, and by addition of each drug to deoxyhemoglobin, respectively. Other spectral changes were attributed to oxidation-reduction reactions between the drugs and the hemoproteins. Each of the reduced forms of hemoglobin showed a higher affinity to aniline and aminopyrine than did methemoglobin. Each of the reduced forms of hemoglobin or reduced cytochrome c showed a higher affinity to aminopyrine than to aniline. It is interesting that not only cytochrome P-450, a hydrophobic hemoprotein, but also hemoglobin and cytochrome c, hydrophilic hemoproteins, showed the drug-induced difference spectra. These results suggest direct interactions between drugs and hemoproteins. Oxyhemoglobin had a lower affinity to drugs in hemolysate than in the buffer only.

Aminopyrine↗
PubMed1978

[Relation between the drug-metabolizing activities of liver microsomes and multiplicity of cytochrome P-450 (author's transl)].

Wada et al. found a hyperbolic curve in the Lineweaver-Burk plots of the drug-metabolizing activity and competitive inhibition of steroid hormones to drugs, and suggested that several enzymes acting on different sites of various steroid hormone molecules might metabolize drugs without having specificities for hydroxylation sites. Recently, several cytochrome P-450s were separated and purified from liver microsomes. We studied the relation between the drug-metabolizing activities and multiplicity of cytochrome P-450 with the pH curve and the Lineweaver-Burk plots. Phenobarbital- and methylcholanthrene-treatment had remarkable effects on the pH curve of aniline hydroxylation by mouse liver microsomes. Addition of cortisol inhibited aniline hydroxylatin by liver microsomes from phenobarbital-treated mice more effectively at higher pH range and the pH curve was similar to that seen for normal mice. Haugen and Coon separated preparations [A] [B] and [C] with hydroxylapatite chromatography and we obtained [A'] (eluted by 100 mM K-phosphate buffer, pH 7.4) between [A] (50 mM) and [B] (300 mM). The preparation [A'] had the same absorption maximum (451 nm) of reduced CO complex as [A], but Km and pH curve for [A'] were similar to those for [B]. Each separated preparation of cytochrome P-450 showed a hyperbolic curve in Lineweaver-Burk plots and a different pH curve from each other.

Aminopyrine N-Demethylase↗
PubMed1977

Studies on fatty acid omega-oxidation. Antiketogenic effect and gluconeogenicity of dicarboxylic acids.

1. Administration of dicarboxylic acids to starving rats decreased the concentration of ketone bodies in the blood. 2. Incorporation of 14C into blood glucose was greater from dicarboxylic acids than from monocarboxylic acids. 3. These results suggest that omega-oxidation may be important for production of succinyl-CoA from fatty acids. 4. In starving or diabetic rats about 15% of palmitic acid were subjected to omega-oxidation and then beta-oxidation.

Animals↗
PubMed1975

Crystallization and properties of rat liver malate dehydrogenase (decarboxylating) (NADP).

Rat liver malate dehydrogenase (decarboxylating) (NADP) ((L-malate: NADP) oxidoreductase (oxaloacetate-decarboxylating), EC 1.1.1.40) was purified and crystallized from medium containing 30 mM Tris-HCl buffer (pH 7.7), 5 mM MgCl2 and 2 mM 2-mercaptoethanol. The enzyme formed rhomboid crystals free from coenzyme, and appeared homogeneous on isoelectric focusing. The crystalline enzyme had an isoelectric point of pH 6.3. Amino acid analysis showed that it contained more acidic amino acids than basic ones.

Amino Acids↗