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Biomedical subjects

I Suzuki

Publications and source records attributed to I Suzuki.

At least 415 records · Page 23Linked to original sources
PubMed1976

[Pharmacological properties of lopramine].

Pharmacological properties of LOP were compared with those of imipramine(IMP). LOP had little or no effect on electroconvulsive shock and chemoconvulsions in mice, conditioned avoidance response in rats, pain threshold in mice and rats and body temperature in rabbits. LOP, unlike IMP, showed relatively weak effects on general behavior in mice, spontaneous EEG in cats and spontaneous motor activity in mice. LOP prevented oxotremorine-induced hypothermia but not tremor, while IMP antagonized both the responses in mice. In anesthetized dogs, LOP caused a respiratory stimulation and a fall in blood pressure, left ventribular pressure and left ventricular dp/dt without a noticeable effect on heart rate. LOP was less potent than IMP in the depressor and cardiodepressing effects, antispasmogenic activity and in antagonizing the depressor response to acetylcholine. LOP, like IMP, potentiated pressor response to norepinephrine and reduced that to tyramine in anesthetized dogs, but neither antidepressant produced norepinephrine potentiation in isolated guinea-pig vas deferens. Both drugs inhibited spontaneous motility of the jejunum without reducing the gastric motility in anesthetized dogs. These results indicate that, compared with IMP, LOP is characterized by weak general pharmacological activities.

Analgesics↗
PubMed1975

A hypocalcemic and lympnocyte-stimulating substance isolated from thymus extracts, and its physicochemical properties.

Two kinds of active protein fraction, TP1 and TP2, were isolated from bovine thymus extracts. Both these fractions showed a single band in polyacrylamide gel disc electrophoresis. Though these two fractions showed a difference in potency, they both lowered serum calcium in rabbits and increased lymphocytes in mice. Molecular weight determination by SDS polyacrylamide gel electrophoresis gave the values of 68,000 for TP1 and 57,000 for TP2. Amino acid composition of TP1 did not show marked characteristics but was clearly different from that of bovine serum albumin. Isoelectric focusing showed the isoelectric point at pH 5.65 for TP1 and pH 5.4 for TP2. Dose-response relation in serum calcium-lowering activity was examined with a sample purified from the extracts, and a linear dependence of the response to log dose was recognized over a moderate range of doses. The time-course measurement of the hypocalcemic activity showed that the action of TP1 is somewhat different from that of calcitonin.

Amino Acids↗
PubMed1975

Lymphocyte-increasing action and hypocalcemic action of parotid gland extract.

It has previously been shown in our laboratory that the hypocalcemic substances purified from the thymus have a potent lymphocyte-increasing action in mice. Then, lymphocyte-increasing activity was examined with bovine parotid gland extracts, which showed a hypocalcemic activity as potent as that of the thymus extracts. The lymphocyte-increasing activity was assayed in the littermates of neonatal mice of Swiss-Webster strain; the materials used for this experiment were purified preparations and several fractions obtained from the parotid gland extracts in the course of purification. It was found that the potency of lymphocyte-increasing activity rose approximately in parallel with the rise in hypocalcemic activity with progress in purification. The final product, which was purified from the gland by isoelectric precipitation at pH 5.4, fractional precipitation with ammonium sulfate, chromatography on DEAE-cellulose, gel filtration on Sepharose 6B and preparative disc electrophoresis, gave a single band in polyacrylamide gel electrophoresis. Its intravenous injection in rabbits, in a dose of 10 mug/kg, produced a significant lowering in serum calcium (percent decrease 10.24 +/- 1.06%) compared with control animals given an injection of physiological saline. Intraperitoneal injection of this purified product, in a dose of 0.5 mug/mouse, in the littermates of neonatal mice, also produced a significant increase (ratio of lymphocytes to polymorphs 2.47 +/- 0.07) in lymphocytes compared with control animals injected with physiological saline (L/P ratio 1.57 +/- 0.05). These facts suggest that this purified protein fraction inherently contains both activities, but the possibility cannot be ruled out of slight contamination by a substance having a high activity. On the other hand, a fraction having no activity for lowering serum calcium but which had activity for increasing the lymphocytes was obtained. This is the first paper to report the presence of lymphocyte-increasing substances in the bovine parotid gland and the purification of one of the substances from the gland.

Animals↗
PubMed1975

Ultrastructure research of the endocardial endothelium of monkeys.

The surface structure of the endocardial endothelium of normal monkeys (Macaca fuscata and M. irus) was studied using scanning and transmission electron microscopy. The endocardium was covered by a layer of endothelial cells, each of which was recognized by the presence of nuclear bulge and marginal folds. The free cell surface was covered by a number of microvilli. The size of the endothelial cell and its surface morphology varied considerably in the different portions of the heart. The endothelial cells were packed more densely along the free margin of the valves especially at the noduli valvularum semilunarum. The microvilli over the cell surface were denser and longer on the ventricular side of the mitral valve and on the aortic valve, where the marginal folds were not "folds" but were formed by an array of numerous microvillous projections. These cytoplasmic projections had a topographical correlation with micro- and macro-pinocytotic vesicles, thus suggesting their role in the interaction with circulating biologically active substances.

Animals↗
PubMed1974

Comparison of butyric type of fermentation in sporogenic and asporogenic mutants of Clostridium botulinum.

Glucose-adapted cells of a sporogenic mutant. MSp(+), and an asporogenic mutant, RSpoIIIa, of Clostridium botulinum type E rapidly fermented glucose, fructose, maltose, and sucrose, resulting in cytoplasmic granulation, heavy growth, a pH of <6.0, and sporulation of the MSp(+) mutant ranging from 60 to 80%. In Trypticase peptone glucose broth, the MSp(+) mutant formed >80% refractile endospores in 25 h, whereas the RSpoIIIa mutant which was blocked at early forespore stage had commenced to lyse. Both mutants accumulated acetate and intracellular granules, reaching maximal levels at early stationary phase of growth. In MSp(+), as the levels of acetokinase, phosphotransacetylase, and butyryl-coenzyme A dehydrogenase reached a maximum, butyrate accumulation continued concurrently with an increase of endospore formation, whereas the levels of poly-beta-hydroxybutyrate decreased simultaneously with its precursor, acetate. Butyrate biosynthesis was blocked in the asporogenic mutant. As shown by isotopic assays, butyrate and acetate serve as precursors of spore lipids. beta-Phenethyl alcohol, fluoroacetic acid, and 2-picolinic acid inhibited anaerobic sporogenesis almost completely, butyrate biosynthesis by >87%, and acetate accumulation by 50 to 62%, showing a direct relationship between butyric type of fermentation and anaerobic sporulation.

Acetates↗