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Biomedical subjects

R Yoneda

Publications and source records attributed to R Yoneda.

At least 73 records · Page 4Linked to original sources
PubMed1980

Experimental partial sympathicotonia, and effects of some drugs on it in restraint and water immersion stressed animals.

The contractile response to acetylcholine (ACh) of the isolated duodenum from the restraint and water immersion stressed (RWIS) mouse was found to be enhanced by the stress for 1 hr and reach a maximum in 3 hr stress followed by a decrease. It was clarified that this rise in the response is not due to the change in the affinity to ACh but due to the increase of the intrinsic activity. The contractile response to KC1 was augmented only when concentration of KC1 was high, While the response to BaCl2 was little enhanced in the stressed animal. The relaxing response to noradrenaline (NA) of the isolated duodenum from rat, on the other hand, was reduced by the stress. Such reduced response to NA was observed to be more marked than the enhanced response to ACh in the vas deferens isolated from the stressed animal. The pretreatment to the RWIS mouse with either antiadrenergic or cholinergic drugs resulted in the clear-cut blockade of the enhancement of response to ACh of the isolated duodenum from this animal. These results contrasted to the effects on the reduced response to ACh of the isolated duodenum from the SART stressed (repeated cold stressed) mouse. The pre-administration of psychotropic drugs showed marked suppression on the enhancement of response of the duodenum of the RWIS animal, though there was a quantitative difference between the RWIS and SART animals. The pretreatment with a neurosedative, Neurotropin (NSP) was also found to show similarly marked suppressive action. From these results, it was considered that the duodenum and the vas deferens of the RWIS animal are in the state of the sympathicotonia, namely partial sympathicotonia.

Acetylcholine↗
PubMed1976

[Central activity, antihypertensive action and antiulcerogenic effects of neurotropin].

Central activity, antihypertensive action and antiulcerogenic actions of Neurotropin (NSP), an extract isolated from vaccinia virus-innoculated skin or tissues of rabbits were investigated herein. When actions of NSP were examined in isolated muscle preparations by the Magnus-method, peristalsis and ACh-induced contraction in the small intestine isolated from crayfish were not influenced, peristalsis and ACh-induced contraction in the small intestine from mice were slightly accelerated, but adrenaline-induced relaxation in the small intestine from mice was not affected. Histamine-induced contraction in the small intestine and tracheal muscles isolated from guinea pigs was antagonized slightly, or not at all by NSP in a high concentration. NSP had no direct action nor anti-ACh action on abdominal muscles from frogs. NSP had no influence on E1-mice-convulsions. Both spontaneous motor activities and exploratory movements in mice were depressed. Sleeping time induced by hexobarbital-Na was prolonged in mice. Tremorine-induced tremor in mice was inhibited by NSP, while perphenazine-induced catalepsy in rats was not. Normal blood pressure in Wistar rats was not influenced, but high blood pressure in SHR (spontaneously hypertensive rats) decreased close to normal levels after NSP. NSP had antiulcerogenic effects on Takagi's restraint-plus-water-immersing ulcers in rats and histamine-induced duodenal ulcers in guinea pigs, but no influence on Shay ulcers in Wistar rats. From the data obtained herein, it may be concluded that NSP has many central depressant-like activities.

Acetylcholine↗
PubMed1976

[Analgesic effects of Neurotropin in mice, and a comparison with analgesic effect of other drugs in SART-stressmice].

Analgesic effects of a neuroleptica "Neurotropin" (NSP) were studied in mice while the analgesic effects of other agents were studied in SART-stress mice (specific stress caused by alterating rhythm in temperature) and the results compared with those in normal mice. NSP is an extract containing many conjugated polysaccarides isolated from the skin or tissues of rabbits which had been inoculated with the living cowpox virus. (a) NSP given alone to normal mice resulted in slight analgesic effects as observed with the application of the acetic acid-, phenylquinon-writhing method or the modified Randall-Selitto method. Little effect was seen when the D'Amour-Smith was used. (b) Synergism was evident when NSP and aminopyrine or NSP and morphine were given concomitantly and the acetic acid- or phenylquinon-writhing methods were applied. (c) Analgesic effects of morphine, levomepromazine, imidazole acetic acid and particularly NSP were greater in SART-stress mice than in normal mice. With the D'Amour-Smith method, only NSP had a greater effect in SART-stress mice than in normal mice.

Aminopyrine↗
PubMed1975

[Stress state caused by alteration of rhythms in environmental temperature, and the functional changes in mice and rats].

Exactly how the organic mechanism corresponds to variations of environmental temperature has not been clarified and for elucidation we reared mice and rats under the conditions of alterating rhythm in temperature (ART). Mice (or rats) were reared at a temperature of 24 degrees C and 8 degrees C (or -3 degrees C) every hour continuously from 10 a.m. to 5 p.m. and at 8 degrees C (or -3 C) from 5 p.m. to the following 10 a.m. Severe stress was evidenced in the animals and was termed specific ART-stress (SART-stress). In this type of stress, there was no apparent increase in body weight, respiration and heart rate were increased slightly and the QRS-time on the ECG was prolonged. ACh sensitivity of the isolated duodenum tested by the Magnus method in SART-stress mice was found to have declined considerably as compared to the normal. Histological observation of the SART-stress rats revealed that the wet weight of the spleen was lighter than that of the controls, while that of the lungs, heart, liver, stomach, kidneys and adrenal glands was close to that of control. Macroscopically, red brown spots of the lungs were visible. Ventricular hypertrophy, slight erosion and hyperemia were present in the interior of the stomach. On the galvanic skin response (GSR) test, electrical resistance of the skin of SART-stress rats was less than that of normal rats and the rate of increase of resistance caused by external stimulus was greater. Recovery time from change in GSR was shorter than in normal animals. Consequently, SART-stress appears to be a form of disease and sudden changes in temperature even in humans may contribute to this state.

Acetylcholine↗
PubMed1975

[Effect of neurotropin on SART stress (stress caused by alteration of rhythms in environmental temperature) in mice and rats].

We reported previously that by altering the rhythm of environmental temperature (ART) the physiological mechanism was changed to an abnormal state which we termed specific ART-stress (SART-stress). In the present report, the effects of neurotropin and other tranquilizers on this SART-stress state were investigated. Neurotropin is an extract containing many conjugated polysaccarides isolated from the skin or tissues of rabbits which had been inoculated with the living cowpox virus. Neurotropin prevented the decrease in body weight of both mice and rats caused by the SART-stress. However, there was no such prevention when an extract isolated from vaccinia virus-uninjured, healthy rabbit skin was given. Chlorpromazine (Cp), reserpine (Rp), diazepam (DZ), imipramine or diphenhydramine gave no protection against the decrease in body weight. Slight increase in number and variation of respirations in SART-stress animals was to some extent prevented by neurotropin. Prolongation of the QRS interval was restored to control with the administration of the above mentioned drugs. Decrease in ACh sensitivity of the isolated duodenum tested by the Magnus-method was prevented by neurotropin. In the galvanic skin response test in rats, decrease in electric resistance on the skin, increase in reactivity and shortening of reaction time caused by SART-stress was prevented to the greatest extent by neurotropin and also to a considerable degree by parenteral administration of DZ or beta-hydroxy gamma-aminobutyric acid (GABOB), the effective results of the drugs being: Neurotropin, DZ, GABOB in that order. Cp and Rp, major tranquilizers were found to be the least effective.

Acetylcholine↗
PubMed1975

Morphological and biochemical studies on the heart of the cardiomyopathic Syrian hamster.

Histological and ultrastructural observations of embryonic hearts and cultured cells from hamsters with inherited cardiomyopathy (BIO 14.6 line) showed a significant delay in maturation of the sarcomeric units in comparison with those of unrelated healthy control hamsters. Phase-contrast microscopic observation of the cultured cardiomyocytes revealed more rapid diminution of beating frequencies in the diseased hamsters than in the controls. Negatively stained ultrastructure and yield of the actomyosin extracted both from the cardiomyopathic and the control hamsters showed no fundamental differences. Disc electrophoresis of the erythrocyte ghosts revealed, at least, a quantitative difference in one of the composing proteins between these two groups.

Actomyosin↗
PubMed1975

[Application of group psychology of animals into pharmacological studies. 12. Specificities of actions of psychotropic drugs on emotional and exploratory behaviors of a single mouse or groups of 2 or 3 animals].

The exploratory movement recorder of Tokyo University of Education type was utilized to assess the exploratory motor activity of groups of 1, 2 and 3 mice of the dd-strain. As the animals were observed during 15 min periods to move spontaneously, psychotropic drugs were administered and the specific actions of these agents were determined. Each drug was given i.p. in a dose which proved non-effective in a single mouse. Observations were as follows: The ratio of exploratory motor activity of each pair of mice as compared to a single mouse was not always different from that of control animals. When a 3rd mouse was added to the pair, the motor activity either increased or decreased considerably. The rate of increase in motor activity was calculated 45 min after caffeine, pentetrazol, ephedrine and DL-amphetamine and was found to be less than in the control animals. After administration of chlordiazepoxide, diazepam, imipramine, chlorpromaxine or mescaline, the rate of increase in motor activity was considerably greater than in the controls. With dimorphoramine or hexobarbital, the rate was much the same as control. After beta-oxy gamma-aminobutyric acid, the rate was slightly increased and with diphenhydramine the rate was slightly less than control. Thus the exploratory motor activity of 3 mice as compared to that of 2, decreased considerably after administration of psychotropic stimulants, while after psychotropic depressants, an even greater increase was observed. We have already reported on the mutual relation of mice in fighting episodes and E1-mice convulsions. Those relations were, however, responses elicited by the physical stimulation. In contrast, the mutual relation in this paper is more of a natural nature. In view of observations in this paper, it is considered that CNS stimulants increase the mutual, emotional, checking behavior in groups of 3 animals while CNS depressants decrease the checking behavior. Such behavior is one example of the emotional conduct when a 3rd party is added to a 2 member group.

Animals↗