PubMed Health⌕ Search

Biomedical subjects

K Fukamachi

Publications and source records attributed to K Fukamachi.

At least 55 records · Page 3Linked to original sources

[Behavioral and EEG effects of coixol (6-methoxybenzoxazolone), one of the components in Coix Lachryma-Jobi L. var. ma-yuen Stapf].

Coixol (6-methoxybenzoxazolone) contained in Coix Lachryma-Jobi L. var. ma-yuen Stapf was compared with chlorzoxazone with respect to behavioral and EEG effects in mice and rats. Coixol 50-100 mg/kg, i.p. decreased locomotor activities of both species and produced hypothermia in rats. These effects of coixol were the same in potency as chlorzoxazone given in the same dose. Coixol was approximately twice as potent as chlorzoxazone in potentiating thiopental-induced sleep. This compound attenuated the writhing syndrome induced by 1% acetic acid and increased the threshold to jumping response induced by foot shock, to the same degree as seen with chlorzoxazone. Coixol was equipotent to chlorzoxazone in preventing convulsions induced by maximal electro-shock, while it was about 1.5 times more potent than chlorzoxazone in suppressing pentylenetetrazol-induced convulsion. Coixol 20-100 mg/kg inhibited the lever pressing response of hypothalamic self-stimulation in rats. In rats with chronically implanted electrodes, coixol 50-100 mg/kg induced drowsy patterns on the spontaneous EEG. The EEG arousal response to the external auditory stimulation was inhibited by the same doses of coixol, whereas it failed to suppress the arousal response to the midbrain reticular stimulation. These results indicate that coixol has pharmacological properties qualitatively similar to chlorzoxazone and acts as a central muscle relaxant with an anti-convulsant effect.

Analgesics↗

[Behavioral and EEG effects of Zingiber mioga Roscoe (water soluble fraction) (author's transl)].

Behavioral and EEG effects of water soluble fraction extracted from Zingiber mioga Roscoe (Z. mioga) were investigated in mice, rats and rabbits. Z. mioga was dissolved in isotonic saline and given i.p. into mice and rats, and i.v. into rabbits, respectively. Z. mioga at doses of 50 approximately 400 mg/kf produced a marked reduction in locomotor activity of mice in the open-field test. The peak time of reduction was 30 min after the injection. In mice, Z. mioga at the same doses lowered significantly the rectal temperature and prolonged the sleeping time induced by thiopental-Na (40 mg/kg, i.v.). Z. mioga at a dose of 400 mg/kg had no anticonvulsant effects and it produced a slight muscle relaxation in mice. Z. mioga at doses of 50 approximately 200 mg/kg induced a significant inhibition of the active conditioned avoidance response of the rat in a shuttle box without affecting the unconditioned escape response. In the step-down method, however, the passive conditioned avoidance response was rarely affected by Z. mioga, but the response was suppressed by chlorpromazine. In rabbits with chronically implanted electrodes, Z. mioga at doses of 20--30 mg/kg induced a drowsy pattern of spontaneous EEG, ilel high voltage slow waves in the neocortex and amygdala, and desynchronization in the case of hippocampal theta waves. The EEG arousal response to the external auditory stimulation was inhibited by the same doses of Z. mioga, whereas it failed to suppress the arousal response to either the midbrain reticular or posterior hypothalamic stimulation, as with chlorpromazine. Neither the recruiting response nor the photic driving response were affected by Z. mioga. On the other hand, the limbic after-discharges to the hippocampal or amygdaloid stimulation were enhanced by Z. mioga as well as chlorpromazin, but they were inhibited by diazepam. The EEG effects of Z. mioga were qualitatively similar to chlorpromazine, but not to diazepam. These results indicate the similarity of behavioral and EEG effects of Z. mioga to those seen with neuroleptics such as chlorpromazine.

Animals↗

Effects of mechanical ventilation and spontaneous respiration on hemodynamics in calves with total artificial hearts.

The effects of respiration on hemodynamics were evaluated in four Holstein calves with total artificial hearts (TAH). The electrohydraulic actuated E4T-TAH has a continuously reciprocating actuator packaged between two alternately ejecting blood pumps that passively fill. The hemodynamic parameters (right atrial pressure [RAP], left atrial pressure [LAP], pulmonary artery pressure [PAP], aortic pressure [AoP]), and right and left pump filling (Rt% fill and Lt% fill) were measured when the animal was intubated and mechanically ventilated. These measurements were repeated with spontaneous respiration after the animal was extubated. With mechanical ventilation, LAP, PAP, and AoP were significantly higher during inspiration than during expiration. However, RAP during inspiration was slightly lower than that during expiration. The Rt% fill during inspiration was significantly lower than during expiration, but Lt% fill during inspiration was significantly higher than during expiration. During spontaneous respiration, these changes were opposite to those observed during mechanical ventilation. That mechanical ventilation generates positive intrathoracic pressure during inspiration, but spontaneous respiration generates negative pressure may explain these results. The change in venous return to the right atrium caused the change in RAP to be opposite in direction to that of the other pressures.

Animals↗