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Biomedical subjects

Y Abe

Publications and source records attributed to Y Abe.

At least 1,207 records · Page 67Linked to original sources
PubMed1976

Purification and properties of an alkaline ribonuclease from the hepatic cytosol fraction of bullfrog, Rana catesbeiana.

In the hepatic cytosol fraction of bullfrog, Rana catesbeiana, an alkaline RNase [EC 3.1.4.22] exists in two forms. One is the free form of RNase, which elutes from a carboxymethyl-cellulose column at a concentration of 0.2 M NaC1. The other is a masked or latent form (RNase-RNase inhibitor complex) which is not adsorbed on the carboxymethyl-cellulose column and which can be converted to the free form of RNase by the addition of p-chloromercuribenzoate. Electrophoretically pure RNase was obtained by the following procedure. The unadsorbed fraction of hepatic cytosol on a column of carboxymethyl-cellulose was treated with p-chloromercuribenzoate and then applied to a second carboxymethyl-cellulose column. The molar weight of RNase was determined to be approximately 12,000 by gel filtration and polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. From the results of gel filtration, the molecular weight of the RNase-RNase inhibitor complex was 130,000. The RNase hydrolyzed poly C, poly U, and poly I, but not poly A or poly G. When poly C was used as a substrate, 2',3'-cyclic CMP as an intermediate and 3'-CMP as a final product were identified. The results of amino acid analysis indicated the presence of an unusual component. The general properties of the RNase and the RNase-RNase inhibitor complex are also reported.

Amino Acids↗
PubMed1976

Effect of angiotensin II antagonist infusion on autoregulation of renal blood flow.

The role of the renin-angiotensin system in the autoregulation of renal blood flow was examined in the anesthetized dog. The angiotensin II antagonist, [1-sarcosine, 8-isoleucine]angiotensin II, was continuously infused into the renal artery at rates of 1 and 3 mug/min, and renin secretion rate and intrarenal distribution of blood flow as well as total renal blood flow were measured during acute reductions in renal perfusion pressure within and below the range of autoregulation. Renal autoregulation and redistribution of blood flow by pressure reduction were not disturbed by the angiotensin II antagonist. This result does not provide any evidence for a primary role of the renin-angiotensin system in renal autoregulation. Redistribution of blood flow by pressure reduction occurred independently of the renin-angiotensin system. It might depend on the differences in the resting tone among the zones.

Angiotensin II↗
PubMed1976

Presence of TSH receptor in thyroid neoplasms.

The nature of the TSH receptor in adenoma and carcinoma of the thyroid gland was studied using a radioreceptor assay technique. A membrane fraction of tissue homogenate was obtained by discontinuous sucrose gradient ultracentrifugation, and 125I-TSH, labelled by a lactoperoxidase method, was purified with a receptor adsorption method. Both the capacities and the association constants of high affinity receptors (4 x 10(9) M-1) and of low affinity receptors (0.073 x 10(9) M-1) observed in the normal thyroid were almost identical to those of the thyroid of Graves' disease and those of thyroid adenoma. Although the two papillary carcinomas examined were found to have two kinds of TSH receptors, one of the carcinomas showed decreased association constants for both high affinity and low affinity receptors.

Adenoma↗
PubMed1976

Relationship between intrarenal distribution of blood flow and renin secretion during ureteral occlusion.

The present study was undertaken to evaluate the relationship between renin secretion from the denervated kidney and intrarenal distribution of blood flow during reductions in renal perfusion pressure by partial constriction of the aorta with and without ureteral occlusion in the anesthetized dog. In addition, renin contents in different zones of the kidney were measured. A reduction in renal arterial pressure from normal pressure (125-135 mmHg) to 77 mm Hg resulted in significant increase in renin secretion and redistribution of cortical blood flow. A further reduction of renal arterial pressure to 51 mmHg produced a marked increase in renin secretion rate (RSR) without further changes in the intrarenal distribution pattern of blood flow. The pressure reductions during ureteral occlusion increased RSR without any change in the distribution pattern of blood flow, and a decrease in the amounts of extractable renin was found in the outer cortex of the experimental kidney. These findings suggest that renin release occurs mainly in the outer cortex, and this process may be stimulated when the mechanism of autoregulation fails as the perfusion presure approaches to the lower range of autoregulation in the outer cortex.

Animals↗
PubMed1976

Relationship between renin secretion and renal autoregulation in the dogs.

The present investigation examined the relationship between renin release and renal autoregulation of blood flow in the anesthetized dogs. A reduction in renal arterial pressure from control pressure to 100mmHg changed neither the flow rates of all cortex zones nor renin secretion. Further reductions of renal arterial pressure to 70mmHg and 50mmHg resulted in a significant increase of renin secretion and a decrease of blood flow in the outer cortex. Intrarenal arterial infusion of acethylcholine abolished an autoregulation of blood flow and pressure reduction to 100mmHg during acetylcholine infusion resulted in a marked increase of renin secretion without any further change in afferent arteriolar resistance. Intrarenal arterial infusion of norepinephrine at a control pressure increased a renin release. However, norepinephrine infusion at reduced pressure suppressed the renin release with recovery a vascular resistance to the control level. These results suggest that the changes in the degree of blood flow and pressure in the renal afferent arterioles are not essential for the renin release, but renin release by the pressure reduction might be related to the autoregulatory capapcity of afferent arterioles in the outer cortex.

Acetylcholine↗
PubMed1976

[Conditioning of emotional behavior caused by hypothalamic stimulation (4). Effects of drugs on conditioned avoidance and escape behavior].

In the present study, effects of psychotropic drugs were analyzed by observing avoidance and escape behavior or rabbits under hypothalamic electrical stimulation. In avoidance behavior, chlorpromazine (CPZ) and diazepam (DZP) depressed avoidance response and extended avoidance response latency and head movement latency. Autonomic behavior such as opening of palpebral fissure and pupil size were also delayed. The locus of movement and count of head movement were depressed by the administration of each drug. On the other hand, unlike CPZ, DZP extended escape response latency. On escape behavior, effects of CPZ and DZP were apparently different. Unlike CPZ, DZP induced avoidance behavior and increased locus of movement. With methamphetamine, no avoidance behavior was observed, but under conditional stimulation, the behavior and the escape response latency were decreased. Chlordiazepoxide induced avoidance behavior.

Animals↗
PubMed1976

[Conditioning of emotional behavior caused by hypothalamic stimulation (3): The learned behavior caused by hypothalamic stimulation in rabbits].

In the present study, the learned behavior caused by hypothalamic electrical stimulation was examined in order to determine the effects of psychotropic drugs. Subjects were albino male rabbits with electrodes chronically implanted in the hypothalamic area. A shuttle box, which was adjusted for behavioral pharmacological estimation of drugs in rabbits, was used. A buzzer sound (85dB) and electrical stimulation of hypothalamus (100 HZ, 1 msec, 1.2-2.0V) were used as the conditional stimulation (CS) and unconditional stimulation (UCS), respectively. The same animal was trained in habituation to a buzzer sound as the CS. For avoidance conditioning in a two-compartment situation, the animal was placed in a shuttle box divided by a hurdle situated at the middle of two-compartments. After the CS was presented for 10 sec, the UCS was given. The animals were subjected to 15 conditioning trials per day. The avoidance and escape behavior model became as distinct by hypothalamic stimulation as by UCS. After termination of the experiments, extinction trials were carried out after which the animals were sacrificed, and localization of the stimulating electrodes was determined histologically.

Animals↗
PubMed1976

Possible retention of the estrogen-binding capacity after endocrine ablation therapy in the rat and human breast cancer.

The estrogen-binding capacity of the regrowing tumors after endocrine ablation surgery was estimated in the rat and human breast cancer. All of 4 tumors that had not had the estrogen receptor before oophorectomy did not show the estrogen-binding capacity after the procedure, in the mammary cancer in the Sprague-Dawley rat induced by 7,12-dimethylbenz[a]anthracene, whereas all the 4 tumors that had the receptor before the procedure showed the binding capacity after oophorectomy. In 4 patients who had been subjected to the major endocrine ablation therapy because of metastatic breast cancer with effective response, the secondary metastatic deposits of cancer showed the estrogen-binding capacity long after the endocrine ablation. The fact that regrowing tumors after complete or partial regression of initial tumors by endocrine ablation retain the estrogen receptor seems to be contradictory to the classical concept of autonomy in recurrence of the breast cancer after hormonal manipulation.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1976

[Conditioning of emotional behavior originating at the hypothalamus. (2) Effects of drugs on conflict-induced behavior models].

We attempted induction of the conflict behavior by the locus pattern, thumping and conditioning under hypothalamic stimulation in rabbits. Flight was classified as continuous and non-continuous. Thumping was elicited post stimulus. Conditioning responses were obtained during the autonomic-somatic responses, continuous run and non-continuous run. All drugs were administrated orally. Dosage of each drug used in this experiment was calculated by determining the dosage which caused the same degree of muscle relaxation and sedative action in mice (see, Fig. 1) or general behavior in rabbits. Diazepam 5 mg/kg, chlordiazepoxide 10 mg/kg and nitrazepam 1 mg/kg caused non-continuous flight in the smooth run, but chlorpromazine 5 mg/kg induced continuous run with snarling. Methamphethamine 5 mg/kg induced continuous run and autonomic-somatic tonus pattern, and phenobarbital-Na 30 mg/kg depressed the animal to the stage of flight. Diazepam, chlordiazepoxide and phenobarbital-Na inhibited thumping, while chlorpromazine, nitrazepam and methamphethamine increased the incidence of thumping. Chlorpromazine transformed the non-continuous run into autonomic-somatic responses of conditioning. Diazepam transformed the non-continuous run into a continuous one. Phenobarbital-Na transformed the non-continuous run into autonomic-somatic responses. Methamphethamine transformed the non-continuous run into a withdrawal response. It would thus appear that the non-continuous flight, thumping and the non-continuous run conditioning are forms of conflict in behavior which can be applied to study of emotional response with psychotropic drugs.

Animals↗
PubMed1976

[Participation of the hypothalamus in conditioning and emotional behavior. (1) Behavior model in rabbits and methods of its analysis].

An attempt was made to induce conflict behavior in rabbits by conditioning under hypothalamic electrical stimulation. Behavioral analysis was performed using our newly devised technique which employs the use of a vibration apparatus fixed to head and waist, and a recording of various behavior. Conditioning was carried out by sensory stimuli flight behavior. Reinforcement was as follows: the CS used was flickering light photic (10 Hz, 10 musec.,) and acoustic (250 Hz, 15 dB) and UCS electrical stimulation (100 Hz, 1 msec., not exceeding 2 v) in the medial hypothalamic area and peri-fornix. The restrained animals were placed on a table in an acoustically isolated room with a discrete monotonous background noise. CRs were obtained within a short time as were responses: (1) During the autonomicsomatic responses, (2) continuous run and (3) non-continuous run. Data obtained during the non-continuous run represent a conflict-induced type of behavior which may be applied in studies related to the psychopharmacological actions of drugs.

Animals↗