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Biomedical subjects

M Matsuzaki

Publications and source records attributed to M Matsuzaki.

At least 19 recordsLinked to original sources
PubMed1978

Comparative effects of cocaine and pseudococaine on EEG activities, cardiorespiratory functions, and self-administration behavior in the rhesus monkey.

The effects of cocaine and pseudococaine on the EEGs, heart and respiratory rates, and self-administration behavior were studied in rhesus monkeys. An intravenous injection of cocaine (2.5 and 4.0 mg/kg) in the monkey produced low-voltage fast waves (LVFWs) in the EEGs and behavioral hyperexcitation accompanied by marked increases in the heart and respiratory rates with mydriasis and excessive salivation. In contrast, pseudococaine produced high-voltage slow waves (HVSWs) in the EEGs and behavioral depression accompanied by the same symptoms of the autonomic functions as those produced by cocaine. Both isomers were self-administered by the monkeys. During cocaine self-administration sessions, the animals showed hyperexcitation in their overall behavior, while with pseudococaine they showed almost normal behavioral responses. These results suggest that cocaine produced excitatory effects and pseudococaine inhibitory effects on the EEGs and behavior. Both isomers stimulate the heart and respiratory rates, and were self-administered by the monkeys.

Animals↗
PubMed1978

Alteration in pattern of EEG activities and convulsant effect of cocaine following chronic adminsitration in the rhesus monkey.

The effects of chronic administration of high doses of cocaine were studied in monkeys (Ss) with electrodes implanted in the brain. The Ss were injected daily with cocaine at a minimal convulsant dose (MCD) during polygraphic recording of EEGs, eye movement, respiratory and heart rates. The initial cocaine MCDs ranged from 3.2 to 6.5 mg/kg i.v. in ten Ss and markedly increased on each successive day following repeated daily injection (75--100% increase within 5--12 days). The elevated daily cocaine MCD was maintained for 1.5--2 months, and thereafter it gradually decreased and stabilized at levels between 20 and 30% above baseline within 2 months. During this period, the duration of daily convulsions evoked by cocaine MCD markedly decreased and stabilized at a constant level (30--35 sec) along with the latency of convulsions. The pattern of daily convulsions evoked by cocaine MCD changed from multiple episodes of intermittent tonic-clonic convulsions, which occurred during the earlier stage (1--2 months) of chronic treatment, to a single episode of sustained tonic-clonic convulsion. The Ss became extremely placid and tame or were profoundly depressed in their overall behavior most of the time. Simultaneously, the Ss continuously showed persistent rhythmic slow waves (5--6 c/sec) predominantly in the neocortex and limbic system structures. The results strongly suggested that chronic cocaine administration at high doses caused relatively permanent alteration of EEGs and behavior in the Ss, and the limbic system structures played an important role in the effect.

Animals↗
PubMed1977

[Studies on the role of high pressure baroreceptors in vasopressin (ADH) secretion. Effect of occlusion of common carotid and vertebral arteries on blood ADH level (author's transl)].

The role of baroreceptors in common carotid and vertebral arteries and arteries in the thoracic cavity in vasopressin secretion was investigated in this study. Effects of bilateral occlusion of common carotid and vertebral arteries on blood ADH level as well as mean arterial pressure were studied in common carotid arterial plexus-denervated dogs, cervically vagotomized dogs and intact dogs. Blood ADH titers were determined by bioassay technic before and 5 minutes after the occlusion of the arteries and were compared with the changes of mean arterial pressure (MAP). The following results were obtained. (1) Blood ADH titers and MAP were elevated by the occlusion of the common carotid arteries in both intact and vagotomized dogs, while they were not significantly affected in denervated dogs. Elevation of blood ADH titers was more pronounced in vagotomized dogs than in intact dogs. (2) Blood ADH titers and MAP were elevated by the occlusion of vertebral arteries in all groups of dogs. However, the elevation of blood ADH titers in denervated dogs was more pronounced than in intact dogs, but less than in vagotomized dogs. (3) The effects of the occlusion of common carotid arteries on blood ADH titers and MPA were more pronounced than those of the occlusion of vertebral arteries. These results may suggest that: a. baroreceptors involved in vasopressin secretion are present in vertebral arteries as well, and that b. the intrathoracic baroreceptors are dominant in controlling vasopressin secretion, while those in common carotid arteries are secondly and those in vertebral arteries thirdly dominant.

Animals↗
PubMed1977

Correlation between serum dopamine-beta-hydroxylase activity and dopamine-beta-hydroxylase and tyrosine hydroxylase activities in central and peripheral adrenergic neurons and adrenal glands.

Serum dopamine-beta-hydroxylase activity in spontaneously hypertensive rats and Wistar-Kyoto rats had a positive correlation with dopamine-beta-hydroxylase and tyrosine hydroxylase activities in mesenteric vessels, vas deferens, and adrenal glands at 14-16 weeks of age, a negative correlation with dopamine-beta-hydroxylase activity in locus coeruleus at 3 weeks and 14-16 weeks of age, and a positive correlation with tyrosine hydroxylase activity only at 3 weeks of age, but not at 14-16 weeks of age.

Adrenal Glands↗
PubMed1977

[Ototoxic effect of BB-K8 administered to pregnant guinea pigs on development of inner ear of intrauterine litters (author's transl)].

UNLABELLED: Transplacental ototoxic effects of BB-K8 on development of inner ear in intrauterine guinea pigs were evaluated by differential frequency pinna reflex test in range of 20 kHZ to 500 HZ and histopathological examination of spiral and vestibular organs in new born guinea pigs from pregnant ones given BB-K8 i.m. during gestation. MATERIALS AND METHODS: Twenty-five pregnant guinea pigs of the Hartley strain and 63 new-born guinea pigs from the pregnant ones were used in the study. Following antibiotics were given i.m. daily to the 20 pregnant guinea pigs from 7th day of gestation for 56 days. BB-K8 was given at the dose level of 100 mg/kg and 200 mg/kg, respectively. Kanamycin (KM) was administered at the dose level of 100 mg/kg and 200 mg/kg, respectively. Physiological saline solution (1.0 ml/kg) was given i.m. to the pregnant guinea pigs for 56 days. The differential frequency pinna reflex test was performed in the frequency range from 20 kHZ to 500 HZ to determine an extent of frequency of pinna reflex loss. The test was carried out before the start of administration of the antibiotics and once a week during the administration. After the last injection of the antibiotics, intravital perfusion fixation was carried out in the new born animals under anesthesia with nembutal. Histopathological examination was made in celloidin serial sections of the cochlea and vestibulum of the new born animals to observe an extent or degree of hair cell damage. RESULTS: (1) The differential frequency pinna reflex test revealed that new born guinea pigs from the pregnant ones given BB-K8 and KM respectively at the dose level of 100 mg/kg did not show occurrence of pinna reflex loss at any frequency tested. At the dose level of 200 mg/kg, BB-K8 did not result in transplacental hearing impairment in new born guinea pigs, but KM caused transplacental pinna reflex loss in the highest frequencies from 20 k to 15 kHZ in 3 of 10 animals. (2) Histopathological examination detected that unilateral incomplete loss of outer hair cells of the spiral organ confined to the basal end of cochlea was found in 3 of 13 new born guinea pigs from the pregnant ones treated with BB-K8 (100 mg/kg). In the animals, slight damage of hair cells in the vestibular organs occurred in 100%. These hair cell damages were enhanced slightly in the new born guinea pigs from the pregnant ones treated with BB-K8 (200 mg/kg) and much more in the new born ones from the pregnant ones treated with KM (100 mg/kg, 200 mg/kg). (3) These results suggest that BB-K8 has a mild potency to cause transplacental ototoxic damage in the inner ear of intrauterine guinea pigs within the pregnant ones treated for 56 days (normal gestation period approximately 70 days).

Amikacin↗
PubMed1976

Dehydrodicaffeic acid dilactone, an inhibitor of catechol-O-methyl transferase.

In the screening of catechol-O-methyltransferase inhibitors, three compounds were isolated from the culture filtrate of a mushroom, Inonotus sp. One was 3,4-dihydroxycinnamic acid (caffeic acid) which had been reported as an inhibitor of this enzyme. The others were the dextrorotatory 2,6-bis-(3',4'-dihydroxyphenyl)-3,7-dioxabicyclo-[3,3,0]-octane 4,8-dione (dehydrodicaffeic acid dilactone) andits antipode. These new compounds inhibited both dopamine beta-hydroxylase and dopa decarboxylase and showed hypotensive activity in the SH rat.

Animals↗