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Biomedical subjects

K Onodera

Publications and source records attributed to K Onodera.

At least 361 records · Page 20Linked to original sources
PubMed1979

Isolation and characterization of tunicamycin resistant mutants from Chinese hamster ovary cells.

Stable clones selected for resistance to tunicamycin (TM) have been isolated from Chinese Hamster Ovary (CHO) cells. The TMR phenotype is stable for more than nine months in the absence of the drug. The morphology of TMR mutant varies from epitheloid to abnormally elongate. The mutants do not display cross-resistance for ConA but are slightly cross-resistant to PHA. Biochemically labeled membrane proteins and glycoprotein of Vesicular stomatitis virus (VSV) grown in the TMR mutants revealed that the incorporation of radioactive glucosamine was markedly reduced in the mutants. The results indicate that TMR cells are a novel type of membrane mutant.

Animals↗
PubMed1979

An analysis of the inhibitory post-synaptic current in the voltage-clamped crayfish muscle.

1. Inhibitory post-synaptic currents (i.p.c.s) were recorded from the feed-back current through a wire electrode inserted longitudinally into the opener muscle fibre of the claw in the crayfish (Cambarus clarkii). 2. I.p.s.c. rose to its peak in about 3-4 msec and decayed approximately exponentially. The decay time constant at -100 mV was 9.4 msec. 3. The decay time constant decreased as the membrane was hyperpolarized and increased during depolarization. The time constant (tau) depends on voltage (V) according to the relation tau = a exp (AV), with a = 18.6 msec and A = 0.0065 mV-1. Voltage dependence was opposite in direction to that seen at frog end-plates, but in the same direction as that of e.p.s.c. in crayfish muscle. 4. At lower temperatures, the rise and fall times of i.p.s.c.s were prolonged. Q10 for the decay time constant was 2.4 between 22.6 and 12.5 degrees C. 5. When pH was decreased from 7.2 to 5.5, the decay time constant increased by about 50%, with little change in the voltage dependence of the time course. 6. When chloride in the solution was changed to iodide, the decay time constant was increased by a factor of 3, while voltage dependence of the time course was not changed. In bromide solution the decay time constant increased by about 50%. 7. Peak amplitudes of i.p.s.c.s were approximately linear as the membrane was depolarized, but they levelled off as the membrane was hyperpolarized beyond reversal potential. The non-linear I-V relation did not result from inadequate voltage clamping, nor from a change in the inside concentration of chloride. After equilibration with iodide solution the I-V relation was approximately linear. 8. The decay time constant was increased after repetitive nerve stimulation. This prolongation became more pronounced at lower temperatures. 9. The kinetic process of the transmitter action is discussed. It is suggested that the rate limiting process for i.p.s.c. is binding and unbinding of the transmitter to the receptor.

Animals↗
PubMed1979

[Interaction of d-pseudoephedrine with water soluble extracts of Platycodi Radix on acute toxicity (author's transl)].

Effect of various combinations of Platycodi Radix water soluble extracts (Pla), 1-ephedrine (1-eph), d-pseudoephedrine (d-pseudo) and Ipecacuanhae Radix water soluble extracts (Ipe) on acute toxicity were examined in mice. Oral LD50 of Ipe, d-pseudo and 1-eph was 490 (415--578) mg/kg, 1550 (1360--1767) mg/kg and 1400 (1102--1778) mg/kg, respectively, while that of Pla was over 10 g. LD50 of Pla Ipe, d-pseudo and 1-eph given intraperitoneally was 1400 (1228--1596) mg/kg 235 (210--263) mg/kg, 245 (229--262) mg/kg and 300 (259--348) mg/kg, respectively. The ratio of the predicted LD50 value, which was calculated on the assumption that each component drug would be additively toxic when combined, to the observed LD50 value was used for comparison. The combination of d-pseudo with Pla gave a significantly greater LD50 value than the predicted LD50 value, while the combination of 1-eph with Pla showed a LD50 value which was not significantly different from Finney's additive model. A combination of d-pseudo with 1-eph and Ipe, and of 1-eph with Ipe showed a LD50 value which was not significantly different from that of the additive model.

Animals↗
PubMed1979

Effect of 5-hydroxytryptophan on muricide response induced by thiamine deficiency.

Male Wistar rats maintained on a thiamine deficient diet showed the mouse-killing response (muricide). On the 30th day of experimental feeding, the incidence of the muricide response was 78% in the thiamine deficient group. Intraperitoneal (i.p.) injection of 5-hydroxytryptophan (5-HTP) suppressed the muricide response in a dose-dependent manner. The suppressive effect of 5-HTP on the muricide response was potentiated by pretreatment with Ro4-4602. On the 20th day of experimental feeding, the incidence of the muricide response was 42.9% in the thiamine deficient group, 14.3% in the pair-fed group and 0% in the control group, respectively. The incidence increased to 92.5% in the thiamine deficient rats 24 hr after the i.p. injection of 100 mg/kg parachlorophenylalanine. The results of the present sutdy indicate that the injection of 5-HTP was effective in suppressing the muricide response induced by thiamine deficiency.

5-Hydroxytryptophan↗
PubMed1979

Surface glycopeptide change triggered by contact between normal cells from rat liver and their simian virus 40-transformed cells from the same virus.

Surface glycopeptide changes triggered by mixed culture of normal cells from rat liver cell line WIRL-3 and simian virus 40-transformed cells from the same line were studied. In addition, biologic responses of the normal cells and the transformed cells to three kinds of surface glycopeptides derived from the normal cells, the transformed cells, and these cells in mixed culture were investigated. Surface glycopeptide derived from the mixed culture showed a quantitative increase and a qualitative change in the glycopeptide structure, not detected in the surface glycopeptide of normal cells and transformed cells cultured separately. The surface glycopeptide changes observed in the mixed culture were mainly ascribable to normal cells responding to transformed cells, and a surface glycopeptide change in normal cells induced a qualitative surface glycopeptide change in transformed cells. Differences in biologic response of normal cells and transformed cells to the above three surface glycopeptides were investigated with the use of inhibition of [3H]thymidine uptake of the cells by the three different surface glycopeptide preparations. The inhibition rates of uptake in normal cells were 30% by all three surface glycopeptides (200 microgram/ml culture medium); inhibition rates in transformed cells were 65% by mixed-culture surface glycopeptide, 50% by normal cell-surface glycopeptide, and 35% by transformed cell-surface glycopeptide.

Cell Communication↗
PubMed1979

A clinical study on urinary kallikrein in patients with renal diseases.

The urinary kallikrein activity (KA) was measured to investigate its significance in the renal diseases by using tosyl-arginine methyl ester (TAME) as a substrate. The examinees were 94 patients with renal diseases and 25 normal persons. The daily urinary kallikrein excretion (KE, KE=KAxdaily urinary volume) is less in chronic glomerulonephritis and outstandingly less in chronic renal failure than in the normal controls. The KE also shows a positive correlation moderately to 15-min PSP excretion and relatively to creatinine clearance. KE is closely related to renal function and decreases with the degree of renal damage. KA has no relation to the concentration of urine protein, but it was parallel, in general, to the urokinase activity. In nephrotic syndrome, KA tends to show a negative correlation to the urinary alpha 1-antitrypsin. alpha 1-antitrypsin may have a function as an inhibitor to the urinary kallikrein.

Adolescent↗
PubMed1978

Effects of membrane potential and temperature on the excitatory post-synaptic current in the crayfish muscle.

1. Effects of membrane potential and temperature on the excitatory post-synaptic current (e.p.s.c.) were studied in the voltage-clamped crayfish muscle. E.p.c. was recorded either by measuring the feedback current through an intracellular wire electrode or by focal recording with an extracellular micro-electrode. 2. The amplitude of the e.p.s.c. obtained by the voltage clamp method varied almost linearly with membrane potential between -100 mV and +70 mV, whilst the reversal potential was +23.8 +/- 3.9 mV (S.E. of mean). 3. The declining phase of the extracellular e.p.s.c. was slightly prolonged by depolarization and shortened by hyperpolarization. Potential dependence of the decay time constant was expressed by tau = a exp (AV), with a = 2.78 msec and A = 0.0037 mV-1. 4. The decay time constant had a Q10 of 2.3 and the growth time had a Q10 of 1.5. 5. The voltage dependence of the decay phase of the e.p.s. was the reverse of that found in frog end-plate. It is concluded that the voltage dependence of the time course is not related either to the charge of ions which carry the synaptic current or to the charge of the transmitter.

Animals↗
PubMed1978

[Muricide induced by thiamine deficiency in the rats (author's transl)].

The emotional behavioral aspects and the interaction between the changes of the polyamine contents and muricide response in thiamine deficient rats were investigated. In the thiamine deficient group, there was evidence of muricide and such increased progressively with advanced thiamine deficient feeding. This muricide was characteristic in the following respects; 1) the killer-rats did not eat but only kill a mouse and it was quite difficult to remove a sacrificed animal from the cage. 2) they bit at random into any body region of the mouse. 3) the killer-rats did not bite inanimate objects such as nails nor chalk. 4) the muricide induced by thiamine deficiency could not be suppressed by a single injection of thiamine HCl. On the 30th day of the experimental feeding, both spermidine and spermine levels in the brain of the thiamine deficient group decreased significantly as compared to the control and the pair-fed groups. Both spermidine and spermine levels were reversed to the control levels with a intraperitoneal administration of thiamine. There were no significant differences in spermine and spermidine levels between the killer-rats and non-killer-rats in the thiamine deficient group.

Aggression↗
PubMed1978

[Persistent erection in thiamine deficient rats (author's transl)].

Male Wistar rats weighing 75 to 85 g and maintained on a thiamine deficient diet for 33 days showed growth inhibition with the principal manifestation of significant weight loss from about the 28 day of experimental feeding. Symptoms of polyneuritis were also evident. On the 20th day of feeding and thereafter, rats on the thiamine deficient diet had a persistent erection. This was observed in 7% of the rats on a thiamine deficient group on day 20, 30.7% on day 25, 63.6% on day 30, and 100% on day 33. Effects of thiamine hydrochloride, in a single dose of 1 mg/kg given subcutaneously on the symptoms of thiamine deficiency were investigated. The treated rats recovered from the polyneuritic symptoms, and persistent erection disappeared in one out of 5 rats on the 3rd day and in 2 more rats on the 7th day. Persistent erection disappeared completely in rats maintained on a thiamine sufficient diet 3 days after single subcutaneous administration of thiamine HCl. These observations suggest that persistent erection was brought on as a consequence of thiamine deficiency.

Animals↗