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Biomedical subjects

S Takase

Publications and source records attributed to S Takase.

At least 235 records · Page 13Linked to original sources
PubMed1988

Neurotransmitter receptors of the rolling mouse Nagoya: a quantitative autoradiographic study.

The distribution of neurotransmitter and neuromodulator receptors was studied in the brain of the rolling mouse Nagoya (RMN) and in controls, using in vitro receptor autoradiography. Quantitative autoradiography was used to map adenosine A1 (labeled with [3H]cyclohexyladenosine), GABAA [( 3H]muscimol), opiate [( 3H]naloxone), L-glutamate [( 3H]L-glutamate), benzodiazepine [( 3H]flunitrazepam), and muscarinic cholinergic [( 3H]quinuclidinyl benzilate) receptors. In the cerebellar cortex, GABAA and adenosine A1 binding sites were significantly reduced in the RMN, whereas other transmitter binding sites were not significantly altered. Adenosine A1 binding sites were also reduced in the cerebral cortex and caudate-putamen. Benzodiazepine binding was significantly decreased in the cerebral cortex and increased in the CA1 subfield of the hippocampus. These results suggest that neurochemical alterations in the caudate-putamen as well as in the cerebellar cortex play important roles in the ataxia and motor dysfunction of the RMN.

Animals↗
PubMed1988

Desmin distinguishes cultured fat-storing cells from myofibroblasts, smooth muscle cells and fibroblasts in the rat.

To differentiate cultured rat liver myofibroblasts, fat-storing cells, aortic smooth muscle cells and skin fibroblasts from each other, desmin and vimentin stainings were undertaken by indirect immunofluorescence using monoclonal antibodies. In myofibroblasts, the reaction with antibodies to vimentin was positive but that with antibodies to desmin was virtually negative. In primary cultures as well as subsequent passage of fat-storing cells, reactions with antibodies to both desmin and vimentin were positive. In primary culture of smooth muscle cells, both reactions were positive, but in the first passage, smooth muscle cells lost the reactivity with antibodies to desmin. Fibroblasts showed a positive reaction with antibodies to vimentin and a negative one with antibodies to desmin. Thus, immunohistochemistry of intermediate filaments allows for the differentiation between fat-storing cells, which are desmin- and vimentin-positive, and myofibroblasts or fibroblasts, which are desmin-negative but vimentin-positive. Smooth muscle cells are also vimentin-positive and become desmin-negative after the first passage.

Adipose Tissue↗
PubMed1988

Hypothalamo-pituitary dopaminergic system in patients with myotonic dystrophy.

We studied the function of hypothalamo-pituitary dopaminergic system in 15 myotonic dystrophy (MyD) patients whose growth hormone (GH) responses to insulin or arginine had been normal. We obtained the following findings: (1) basal levels of plasma GH and prolactin (PRL) were normal, although the latter levels were slightly lower than controls, (2) both GH and PRL responses to L-dopa or bromocriptine were significantly blunted compared with controls, (3) PRL response to sulpiride was also significantly low compared with controls. These results indicate that hypothalamic dopaminergic neuron and its postsynaptic dopamine receptors relating to GH secretion might be impaired. It was also suggested that the dopamine receptors of pituitary PRL cells might be impaired and the PRL reserve of pituitary cells might be decreased in some case.

Adolescent↗
PubMed1988

Hydrolysis of alpha-D-glucopyranosyl-1,6-sorbitol and alpha-D-glucopyranosyl-1,6-mannitol by rat intestinal disaccharidases.

The hydrolyzing activities in rat small intestine for newly developed sugar substitutes, alpha-D-glucopyranosyl-1,6-sorbitol (GPS) and alpha-D-glucopyranosyl-1,6-mannitol (GPM), both of which are produced by hydrogenation of palatinose, were characterized. GPS and GPM were hydrolyzed in mucosal homogenate as well as in brush border membranes of rat small intestine at a slower rate than the rate of hydrolysis of palatinose (30%) and sucrose (6-7%). Gel filtration column chromatography of disaccharidases solubilized from brush border membranes revealed that GPS and GPM were hydrolyzed mainly by sucrase-isomaltase complex and its degradation product, i.e. isomaltase monomer. The isomaltase monomer, purified from small intestine of rats, possessed similar Km values for GPS (2.47 mM) and GPM (5.38 mM) as compared to those of purified sucrase-isomaltase complex. The Vmax values of isomaltase monomer for GPS and GPM were twice as high as those of sucrase-isomaltase, suggesting that GPS and GPM are hydrolyzed by the active site of isomaltase. On the other hand, a small amount (up to 17%) of GPS- and GPM-hydrolyzing activities was ascribed to glucoamylase, which possessed relatively high Km values for GPS (18.7 mM) and GPM (32.9 mM). To examine a physiological significance of GPS- and GPM-hydrolyzing activities, the transmural potential difference (delta PD) evoked by Na+-dependent active transport of glucose, produced by the hydrolysis of these disaccharide alcohols, was measured in everted segments of rat jejunum. The relative rates of absorption of glucose produced by the hydrolysis of GPS and GPM were 36% and 27% of that of palatinose, directly reflecting the hydrolyzing activities determined in jejunal homogenate. These results suggest that the process of hydrolysis is the rate limiting step in digestion-absorption process of palatinose, GPS and GPM in small intestine.

Animals↗
PubMed1988

Connective tissue components in cultured parenchymal and nonparenchymal cells of rat liver. Immunohistochemical studies.

Connective tissue components were detected immunohistochemically in cultured rat hepatocytes and sinusoidal lining cells. In the Ito and endothelial cells, the staining reactions to prolyl hydroxylase were strong. The reaction in the hepatocytes, however, was weaker, and there was no staining reaction to prolyl hydroxylase in the Kupffer cells. In the Ito cells, types III and IV collagen were clearly positive, whereas reactions to type I collagen were very weak. In the endothelial cells, type IV collagen stained clearly, whereas the reaction for type I collagen was very weak, and there was no reaction for III. Laminin was clearly positive in the Ito and endothelial cells. Connective tissue components were not detectable in the Kupffer cells. The hepatocytes were positive for types I, III, and IV collagen, but the staining reactions to type IV collagen were weak. Laminin staining was almost negative. These results suggest that type IV collagen is produced mainly by nonparenchymal cells and that types I and III collagen are produced by both parenchymal and nonparenchymal liver cells.

Animals↗
PubMed1987

Effects of malotilate on ethanol-inhibited hepatocyte regeneration in rats.

The effects of malotilate, a hepatotrophic drug, on the inhibition of hepatocyte regeneration induced by ethanol were studied in rats. Following acute ethanol administration, both DNA synthesis and commencement of the S phase of the cell cycle in hepatocytes after partial hepatectomy were delayed. Malotilate prevents this ethanol-induced delay. Upon chronic ethanol administration, DNA synthesis after partial hepatectomy was reduced and commencement of the S phase was retarded. Treatment with malotilate clearly lessened the reduction in DNA synthesis in the resected liver, and retardation of the cell cycle was partially inhibited. These results indicate that malotilate prevents the ethanol-induced inhibition of hepatocyte regeneration at the dose tested and that this drug may be effective for the treatment of alcoholic liver disease.

Animals↗
PubMed1987

Cellular vitamin A-binding proteins in the testis.

Vitamin A plays an important role in the testis, being essential for the maintenance of spermatogenesis. Studies on CRBP and CRABP suggest that both retinol and retinoic acid are involved in maintaining testicular function. The cellular location of the two proteins suggests that retinoic acid may be particularly involved in the later stages of germ cell differentiation, but retinol may be the form of vitamin A that the Sertoli cell receives initially. The requirement for vitamin A may be to regulate gene expression in the testis by direct interaction with the chromosomal material. Specific distinct binding sites for retinol and retinoic acid can be demonstrated in testicular nuclei and chromatin. These sites are only revealed when the two ligands are present in complex with their specific binding proteins, suggesting that these proteins may be required for the action of retinol and retinoic acid in some cells of the testis.

Animals↗
PubMed1987

Comparative studies on clinical features and CSF proteins of motor neuron disease patients.

Clinical features such as types of diseases, sex ratio, age of onset, sites of initial involvement, the appearance of bulbar signs, and duration of illness were studied in 52 patients with motor neuron disease (MND) with a special reference to immunoglobulin in cerebrospinal fluid (CSF) and serum. Although MND has been thought to be a degenerative disease of unknown cause, our data suggested there are some immunological abnormalities in this disease. The duration of illness and the abnormalities of CSF immunoglobulins appeared to be correlated with the type of disease and the site of initial involvement. However, whether or not these abnormalities in CSF immunoglobulins are directly related to the pathogenesis of MND remains unclear.

Adult↗
PubMed1987

Endocrinological abnormalities in myotonic dystrophy: consecutive studies of eight tolerance tests in 26 patients.

We studied endocrine functions of the hypothalamus, pituitary, thyroid, gonad, adrenal and pancreas in 26 patients with myotonic dystrophy. The following findings were obtained: (1) Hyporesponsivenesses of HGH to insulin, arginine and L-dopa test were observed in 25%, 45% and 54.5% of patients, respectively. To the administration of sulpiride and TRH, hypo- or hyperresponses of plasma PRL were observed in 4 or 2 patients, respectively. (2) Depressed plasma levels of testosterone were observed in 4 patients and those of estradiol were observed in 3 patients. Among these 7 patients, five were hypergonadotropic and the remaining two were hypogonadotropic. From the data of plasma cortisol and urinary 17-OHCS, the adrenal functions in patients with myotonic dystrophy were considered to be normal. The renin-angiotensin-aldosterone systems in these patients were considered to be grossly normal. (3) Basal levels of T3, T4 and free T4 were within the normal ranges, but 6 of 19 patients showed low levels of 131I-uptake and 11 of 24 patients showed reduced BMR values. (4) The basal level of plasma insulin was elevated in 5 patients. Insulin responses to oral glucose were exaggerated and delayed in 21 of 26 patients. From these results and the statistical evaluation of each laboratory and clinical data, we concluded that 1) the degrees of disturbances of endocrine functions are at random in each patient. 2) The measures of intellectual function obtained by WAIS were directly correlated with basal levels of TSH, but inversely with basal levels of somatostatin. No specific correlation was found between endocrinological disturbances and neurological severities. 3) Impairment of some endocrine functions, such as the gonadal, thyroid and somatotroph functions, was closely correlated with age and the duration of disease.

Adolescent↗
PubMed1987

Possible role of insulin status in the increased lipogenic enzyme activity by dietary medium-chain triglyceride in rat liver.

The possible role of insulin status in the increase in liver lipogenic enzyme activities upon feeding medium-chain triglyceride (MCT) was investigated with streptozotocin-induced diabetic rats and insulin-treated diabetic rats. Rats were fed synthetic diets that contained either 2% corn oil (control), fat free, 13% MCT +2% corn oil, or 13% lard +2% corn oil, respectively. Feeding the MCT diet for 3 days increased serum ketone bodies in both the normal and diabetic rats. Insulin levels of MCT-fed rats tended to be higher than in normal animals. MCT feeding caused an enhancement of fatty acid synthetase (FAS) and malic enzyme (ME) in the liver of normal rats, whereas diabetic rats failed to register an increase in those activities due to MCT feeding. Administration of insulin to diabetic rats resulted in a recovery of the level of those enzyme activities to about the same degree as in each of the normal rat groups. It was interesting that diabetic MCT-fed rats with insulin treatment maintained higher enzyme activities in comparison to the lard and control groups. These results suggest that the increase in lipogenic enzyme activities caused by dietary MCT is presumably dependent on differences in insulin status.

Animals↗
PubMed1986

Transfer of retinoic acid from its complex with cellular retinoic acid-binding protein to the nucleus.

Cellular retinoic acid-binding protein (CRABP), a potential mediator of retinoic acid action, enables retinoic acid to bind in a specific manner to nuclei and chromatin isolated from testes of control and vitamin A-deficient rats. The binding of retinoic acid was followed after complexing [3H]retinoic acid with CRABP purified from rat testes. The binding was specific, saturable, and temperature dependent. If CRABP charged with nonlabeled retinoic acid was included in the incubation, binding of radioactivity was diminished, whereas inclusion of free retinoic acid, or the complex of retinol with cellular retinol binding protein (CRBP) or serum retinol binding protein had no effect. Approximately 4.0 X 10(4) specific binding sites for retinoic acid were detected per nucleus from deficient animals. The number of binding sites observed was influenced by vitamin A status. Refeeding vitamin A-deficient rats (4 h) with retinoic acid lowered the amount of detectable binding sites in the nucleus. CRABP itself did not remain bound to these sites, indicating a transfer of retinoic acid from its complex with CRABP to the nuclear sites. Further, CRBP, the putative mediator of retinol action, was found to enable retinol to be bound to testicular nuclei, in an interaction similar to the binding of retinol to liver nuclei described previously.

Animals↗