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Biomedical subjects

S Ueda

Publications and source records attributed to S Ueda.

At least 1,117 records · Page 62Linked to original sources
PubMed1979

Effects of prostaglandin E1 on isolated dog renal artery.

Actions of prostaglandin (PG) E1 were investigated using isolated dog renal arterial strips. Norepinephrine increased the tension of the renal arterial strips contracted with potassium, and this response was depressed by phentolamine. Isoproterenol produced relaxant effects on these arteries, and this response was converted to contractile one by propranolol. Diltiazem dose dependently relaxed the potassium-contracted strips. PGE1 (10(-9)-3 X 10(-8) Gm./ml.) constricted the renal arterial strips, while in higher concentrations (10(-7)-3 x 10(-7) Gm./ml.) it caused relaxations of them. Contractile responses by PGE1 were not affected by phentolamine or phenoxybenzamine, but were suppressed by diltiazem. On the other hand, relaxant effects of PGE1 were not changed by propranolol. Papaverine or theophylline significantly inhibited the contractions induced by PGE1. From these results it is suggested that (1) in the dog renal artery adrenergic alpha-receptors must be more dominant than beta-receptors; (2) PGE1 will produce a depolarization of renal arterial smooth muscle and/or increase an active transport of calcium ions into smooth muscle cells; and (3) the relaxant responses by PGE1 may be related to an increase in cellular cyclic adenosine monophosphate (AMP) contents.

Animals↗
PubMed1979

Polymorphism of red cell glutamic-pyruvic transaminase in Japanese: gene frequencies in samples from Northern Japan.

The genetic polymorphism of red cell GPT was investigated by starch-gel electrophoresis in four samples from northern Japan including a sample of the Ainu of Hokkaido. The distribution of the Gpt1 gene frequencies among 10 samples excluding the Ainu so far examined showed heterogeneity. The geographical cline of Gpt1 gene frequency reported in southern Japan was not observed in northern Japan.

Adult↗
PubMed1979

Cardiac atrial myosin adenosine triphosphatase of animals and humans: distinctive enzymatic properties compared with cardiac ventricular myosin.

Cardiac myosin obtained from atria had a higher Ca2+-activated ATPase activity than did cardiac myosin from ventricles in various species of animals and in humans. The increased specific activity of Ca2+-activated adenosine triphosphatase (ATPase) of atrial myosin appeared to correlate with the level of the activity of ventricular myosin ATPase in the animal, since the same order in ATPase activity, as observed in ventricular myosins from various animals, was noted in atrial myosins. The enzymatic properties of atrial myosin also were characterized by no activation by N-ethylmaleimide, low activating energy, and a lower rate of inactivation at alkaline pH compared with the same properties of ventricular myosin. These findings suggest a difference in the myosin molecule at or near the active site, involving some sulfhydryl groups, between the two types of cardiac myosin. The Mg2+-activated ATPase activity, both in the presence and absence of actin (which is thought to be closely related to the basic contraction mechanism), also was enhanced in atrial myosin. Thus, the ATPase activities of atrial and ventricular myosins were different with special reference to the reaction pathway involving calcium and magnesium ions and appear to account for the difference in the velocity of contraction between the atria and the ventricles.

Adenosine Triphosphatases↗
PubMed1979

Studies on tetrahydrofuranyl-5-fluorouracils. 2. NMR studies of 1-(tetrahydro-2-furanyl)-, 3-(tetrahydro-2-furanyl)-, and 1,3-bis(tetrahydro-2-furanyl)-5-fluorouracils.

Measurements of the 1H NMR spectra of the diastereoisomers of 1-(tetrahydro-2-furanyl)-5-fluorouracil, 3-(tetrahydro-2-furanyl)-5-fluorouracil, and 1,3-bis(tetrahydro-2-furanyl)-5-fluorouracil in the presence of tris[3-(2,2,2-trifluoro-1-hydroxyethylidene)-d-camphorato]europium(Eu(TFC)3) as a chiral shift reagent showed differences between the isomers in the chemical shift changes of the protons of C2'-H and C6-H etc.

Fluorouracil↗
PubMed1979

Analysis of vasodilatory action of a new nitroester agent, 2-nicotinamidoethyl nitrate (SG-75).

Effects of 2-nicotinamidoethyl nitrate (SG-75) on cardiovascular system were investigated using whole animals and isolated vascular smooth muscles of dogs and rabbits. In dogs in vivo SG-75 i.v. produced dose-dependent falls in systemic blood pressure (SBP) concomitant with increases in heart rate (HR). Hypotension by SG-75 was not affected by propranolol and atropine but slightly inhibited by diphenhydramine. Norepinephrine (NE) dose-dependently increased SBP, and SG-75 could not affect these effects of NE. In dog coronary arterial strips contracted with potassium, SG-75 produced a dose-dependent relaxation of these strips. These effects of SG-75 were not affected by propranolol and atropine, but slightly inhibited by diphenhydramine. NE dose-dependently increased the tension of helical strips prepared from rabbit femoral artery, rabbit aorta and dog coronary artery. But SG-75 could not alter these effects of NE. The results suggest that SG-75 may have not an adrenergic beta-receptor stimulating action, a muscarinic action and an adrenergic alpha-receptor blocking action, but an inconsiderable histamine-like action. Probably, a main action of SG-75 may be a nitroglycerin-like action.

Animals↗
PubMed1978

Immobilization of Streptomyces flavochromogenes pullulanase on tannic acid and TEAE--cellulose.

Pullulanase was immobilized successfully by simple, inexpensive methods that may be useful for industrial application of this enzyme. A tannin--pullulanase(TP) complex was obtained by addition of tannic acid to the culture filtrate of thermophilic Streptomyces flavochromogenes. TP could be bound to TEAE--cellulose (TTCP). Immobilization in this manner took place with quantitative retention of activity. The immobilized enzymes were stable for more than six months. The optimum temperatures of the native enzyme and TP were both 50 degrees C; that of TTCP was 45 degrees C. In the presence of 5mM Ca2+, the activity of TTCP was increased approximately twofold and the optimum temperature was raised to 50--60 degrees C. Pullulanase was not significantly eluted from TP or TTCP by NaCl solution (0.1--0.5M).

Enzymes, Immobilized↗