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Biomedical subjects

Y Satoh

Publications and source records attributed to Y Satoh.

At least 577 records · Page 32Linked to original sources
PubMed1984

Stability of receptor complexes in the rat ventral prostate and seminal vesicle bound to androgens: thermodynamic study.

To examine the behaviour of the receptor-acceptor system of androgen of different biopotencies, we compared the stability of receptor complexes of dihydrotestosterone (DHT), methyltrienolone (R1881) and testosterone (Test) in cytosols, nuclei and nuclear extracts from ventral prostate and seminal vesicle of rats. Liberation of ligand from receptor complexes bound to these ligands followed the first-order kinetics. The rate constant for ligand liberation at 25 degrees C varied with the ligand. The receptor complexes bound to Test were most labile, while the receptor complexes bound to DHT were relatively stable, and intermediate stability was observed in the receptor complexes bound to R1881 under the conditions employed in the present study. Thermodynamic characteristics of the stability of the complexes were also different in these three androgens. The Arrhenius plots of the rate constant for the liberation of ligand from R1881- and DHT-receptor complexes in cytosols and nuclei showed curvilinearities, but the plots for Test-receptor complexes were almost linear. In addition, the stabilizing effect of molybdate on R1881- and DHT-receptor complexes in cytosols was observed in the range of low temperature, while the effect on Test-receptor complexes was significant at the higher temperature. The differences observed in the present study seem to be related to the difference in the biological potency of these androgens.

Animals↗
PubMed1984

[Pharmacokinetics of human fibroblast interferon in rats].

Pharmacokinetic behaviors of human fibroblast interferon (HuIFN-beta) administered intravenously to rats were examined. After intravenous injection, plasma interferon level decreased in a biexponential fashion having the half-times of 15 min and 120 min respectively. Distribution levels of HuIFN-beta in the tissues at 30 min, though the actual concentrations were less than that of plasma, were observed according to the following order; kidney greater than adrenal greater than lung greater than spleen greater than liver greater than testis. Small amounts of HuIFN-beta were also detected in the thoracic lymph and bile but no HuIFN-beta was found in urine. The in vitro study indicated that the stability of HuIFN-beta was different in each tissue homogenates and body fluids. From the results obtained, we concluded that HuIFN-beta exhibited a low distributional character to the tissues when administered intravenously. It was also suggested that the kidney and the liver were the main catabolic sites of HuIFN-beta.

Animals↗
PubMed1983

Effect of zotepine and various drugs on apomorphine- and methamphetamine-induced rotational behaviour in rats with unilateral lesions of the substantia nigra.

The effect of zotepine (2-chloro-11-(2-dimethyl-aminoethoxy) dibenzo [b, f] thiepin), a new neuroleptic, and other neuroleptics, minor tranquilizers, antidepressants, anticholinergic drugs, antihistamine drugs, antiparkinsonian drugs, alpha-, beta-adrenergic blocking agents, hypnotics and central muscle relaxants on apomorphine (APM)- and methamphetamine (MAP)-induced rotational behaviour was investigated in rats with unilateral lesions of the substantia nigra. Only the neuroleptics dose-dependently depressed both rotational behaviours. The minor tranquilizers also depressed both behaviours, but their effect was non-specific. The neuroleptics could be divided into two groups according to their relative effect on the APM- and MAP-induced rotational behaviour. The high-ratio group (fluphenazine, haloperidol, perphenazine, pimozide and zotepine) depressed the MAP-induced rotational behaviour more strongly than the APM-induced one, whereas the depressive effect of the low-ratio group (chlorpromazine, levomepromazine, thioridazine and clozapine) was the reverse. Zotepine, while belonging to the high-ratio group, was markedly lower in ratio than the other neuroleptics in this group. The correlation between the different effect of the two groups of neuroleptics and their clinical effect is discussed.

Animals↗
PubMed1983

Receptor recycling: liberation of glucocorticoid receptors from liver nuclei in vitro.

Dynamics of the steroid receptors seems to be the consequence of receptor recycling. In the present study, as a clue to elucidate the mechanism of receptor recycling, factors which affect the rate of liberation of nuclear bound 3H-glucocorticoids were examined in vitro. Among the factors examined, NAD, NADPH, cAMP and p-nitrophenyl phosphate accelerated the liberation of radioactivity from nuclei in a temperature-dependent manner when added to the incubation mixture. The presence of a large amount of unlabeled dexamethasone (Dex) did not modify the rate of liberation. From these results, it was concluded that the metabolism of ligand bound to the receptor is not a necessary step in the liberation of receptor from nuclei. These agents did not influence the binding process of 3H-Dex-receptor complex to DNA-cellulose. Therefore the stimulation of receptor release does not seem to be mediated by reducing the binding affinity between nuclei and receptor complexes. The liberated radioactivity was eluted on a Sephadex G-100 column in the void volume and in macromolecule-unbound fractions. In both fractions, the majority of the radioactivity comigrated with authentic glucocorticoids on thin-layer chromatography.

Animals↗
PubMed1983

Cardiac involvement in mucolipidosis. Importance of non-invasive studies for detection of cardiac abnormalities.

Although mucolipidosis, a fatal metabolic storage disorder, is associated with cardiovascular abnormalities, detailed, non-invasive cardiac examinations have not been well documented. We studied 4 children with type II and type III mucolipidosis, 3 of whom had unequivocal evidence of aortic regurgitation characterized by phonocardiography and M-mode echocardiography. Two-dimensional echocardiography showed an aortic valve prolapse in 3, a mitral valve prolapse in 2 and a tricuspid valve prolapse in 1. The QT interval was prolonged in 2 cases. In 1 autopsy case, we found considerably thickened and retracted aortic, mitral, and tricuspid valves, and accumulation of the foam cells in the myocardium. Echocardiography revealed similar findings in another 3 cases. We conclude that cardiac manifestations in this disorder should be examined carefully particularly by the use of echocardiography which is an excellent technique for detecting cardiovascular abnormalities in mucolipidosis.

Adolescent↗
PubMed1983

Ultrastructure of the corpuscular nerve ending in the lymph heart of the turtle (Pseudemys scripta elegans).

Corpuscular nerve endings were found in the tunica externa of the lymph heart of a turtle (Pseudemys scripta elegans). They consisted of axon terminals and surrounding cellular lamellae. Serial thin sections of one such presumable sensory corpuscle were made and reconstructed for the three-dimensional analysis of the corpuscle, with special reference to the axon terminals. It was revealed that axon terminals ramified at several points within the corpuscle and formed varicosities of various sizes ranging from 1.0 to 3.0 microns in diameter in their courses. Such varicosities contained an abundance of mitochondria as well as clear and granular vesicles 500 to 800 A in diameter. Finger-like protrusions often projected from the axon terminals into the interlamellar spaces. The lamellae consisted of several thin cytoplasmic processes of modified Schwann cells. The corpuscle was enclosed in an incomplete capsule consisting of a thin layer of cellular processes. The corpuscular nerve endings may represent pressoreceptors in the wall of the lymph heart.

Animals↗
PubMed1983

Diurnal changes in lipolytic activity of isolated fat cells and their increased responsiveness to epinephrine and theophylline with meal feeding in rats.

Diurnal changes in glycogen stores of adipose tissues and in vitro lipolytic activity of isolated epididymal fat cells, and their lipolytic responsiveness to epinephrine and theophylline were examined in rats adapted to a 2-h daily meal feeding (20.00-22.00 h; darkness between 20.00-08.00 h) for 3 weeks and in control rats fed ad libitum. The fat cells from both groups of animals showed the peak of lipolytic activity at the mid-dark period (03.00 h), but the peak values and the average values at 6 or 7 time points examined within the 24-h feeding cycle were significantly higher (p less than 0.025) in meal-fed rats. Basal, epinephrine-stimulated, and epinephrine-induced lipolysis of fat cells from control rats showed diurnal changes, and the rhythms and their amplitude were affected by meal feeding. Changes in lipolytic activity of fat cells did not seem to relate directly to those of glycogen stores in adipose tissue. The over-all 24-h means of lipolytic activity of fat cells were significantly increased (p less than 0.001) with meal feeding. Mean cell size of epididymal fat pads was significantly smaller (p less than 0.001) in meal-fed rats, but lipolytic responsiveness to the graded concentrations of epinephrine and theophylline in the incubation medium was significantly greater (p less than 0.001) in meal-fed rats than in rats fed ad libitum. Thus, these findings suggest that lipolytic activity of the cAMP-hormone sensitive lipase system in fat cells might be increased with meal feeding in rats. Furthermore, the present results may give a new idea to consider the discrepancy that many workers have not been able to observe the increase in body fat deposition with meal feeding, which has been frequently reported to enhance lipogenesis in rats.

Adipose Tissue↗
PubMed1983

Effect of voluntary running exercise on hypertriacylglycerolemic effect of sucrose in relation to its feeding timing in rats.

The effect of voluntary wheel-running to modulate sucrose-induced hypertriacylglycerolemia was investigated on both sedentary and exercised rats in relation to the timing of sucrose feeding. The exercised group was allowed voluntary wheel-running between 21.00-08.00. Rats of both groups were daily meal-fed a 35% sucrose diet at 20.00-21.00 and a basal diet at 08.00-09.00, or inversely meal fed the two diets at the reversed time for 7 weeks each. At the end of the feeding period, plasma or serum triacylglycerol (TG) levels of exercised rats, as compared to sedentary rats, showed smaller diurnal changes regardless of the timing of sucrose feeding. Hepatic-intestinal TG secretion rates measured during both resting and physically active periods were lower in the exercised rats than in the sedentary control rats, whereas the cardiac and adipose tissue lipoprotein lipase activity of the two groups was not significantly different. These results suggest that voluntary wheel-running exercise may modulate the hypertriacylglycerolemic effect of sucrose in rats regardless of the timing of sucrose feeding, with decreased TG secretion.

Adipose Tissue↗
PubMed1983

An epidemic of non-A, non-B hepatitis in Japan.

An epidemic of viral hepatitis was studied in the Okitsu area of Shimizu city in Japan from April 1980 to November 1981. One hundred thirty-six serum samples from patients with viral hepatitis were tested for hepatitis B virus, hepatitis A virus, Epstein-Barr virus, and cytomegalovirus infection. Immunoserological data showed the outbreak of viral hepatitis to be non-A, non-B hepatitis. Epidemiological investigations revealed that the mode of the outbreak was from person to person by close contact and the incubation period was from about 2 to 5 months.

Adolescent↗