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S Suda

Publications and source records attributed to S Suda.

At least 91 records · Page 5Linked to original sources
PubMed1983

The effects of intravenous norepinephrine on the local coupling between glucose utilization and blood flow in the rat brain.

Norepinephrine was infused intravenously in two groups of normal, awake rats. In one group local cerebral glucose utilization (LCGU) was measured by the deoxyglucose method (Sokoloff et al. 1977b); in the other group local cerebral blood flow (LCBF) was determined by the iodoantipyrine method (Sakurada et al. 1978). The experiments were performed during a stable state in which the heart rate was reduced between 36% (LCGU experiments) and 27% (LCBF experiments). Norepinephrine infusion reduced LCGU in all 39 structures measured between - 18 and - 37% from control values obtained in a group of normal non-infused rats. The decrease in LCGU was significant (P less than 0.05) in 38 of the 39 structures tested. LCBF was increased but not statistically significantly in most of the structures examined. When the LCGU values of the various structures during norepinephrine infusion were correlated with their corresponding LCBF values, a tight correlation (r = 0.94) was found indicating a close coupling between LCGU and LCBF during norepinephrine infusion. When compared to the relationship between LCGU and LCBF in a normal, non-infused control group, the slope of the regression line was increased significantly (P less than 0.01) by the norepinephrine infusion, indicating a resetting of the coupling mechanism. This means that, at a given metabolic rate, a higher blood flow is needed to perfuse a brain structure during norepinephrine infusion than during control conditions.

Animals↗
PubMed1983

1 alpha,25-dihydroxyvitamin D3 promotes fusion of mouse alveolar macrophages both by a direct mechanism and by a spleen cell-mediated indirect mechanism.

Extensive fusion was induced in mouse alveolar macrophages by treatment with conditioned media obtained from spleen cell cultures treated with 15 micrograms of phytohemagglutinin or concanavalin A per ml or with 12 nM 1 alpha,25-dihydroxyvitamin D3 [1 alpha,25(OH)2D3]. The fusion rate was 80-90% on day 3. In addition, 1 alpha,25(OH)2D3 added directly to alveolar macrophages induced fusion of about 35% of the cells on day 3, whereas direct addition of phytohemagglutinin and concanavalin A did not enhance fusion at all. When conditioned media from spleen cell or T cell cultures treated with 12 nM 1 alpha,25(OH)2D3 were applied to a Sephadex G-100 column, a fusion factor (Mr 37,000-70,000) could be separated from 1 alpha,25(OH)2D3. 1 alpha,25(OH)2D3 induced fusion at 0.012-120 nM in a dose-dependent manner both by direct action and by spleen cell-mediated indirect action, but the fusion rate was always much greater in the latter than in the former at each concentration of the vitamin. Of the vitamin D3 derivatives tested, 1 alpha,25(OH)2D3 was the most potent, followed successively by 1 alpha,24R,25-trihydroxyvitamin D3, 1 alpha-hydroxyvitamin D3, 25-hydroxyvitamin D3, and 24R,25-dihydroxyvitamin D3. These results clearly indicate that 1 alpha,25(OH)2D3 induces fusion of mouse alveolar macrophages by both a direct and an indirect mechanism, the latter mediated by spleen cells, probably by T cells.

Animals↗
PubMed1981

Changes in protein synthesis underlying functional plasticity in immature monkey visual system.

Local rates of cerebral protein synthesis were determined in newborn rhesus monkeys subjected to either acute or chronic monocular visual deprivation. Chronic monocular deprivation resulted in decreased rates of protein synthesis in the laminae of the lateral geniculate nuclei innervated by the deprived eye whereas rates of protein synthesis were normal in geniculate laminae innervated by the functioning eye. Acute monocular deprivation produced no differential changes in rates of protein synthesis in any of the geniculate laminae.

Animals↗
PubMed1981

Local cerebral glucose utilization and blood flow during metabolic acidosis.

The relationship between local cerebral glucose utilization (LCGU) and local cerebral blood flow (LCBF) was studied in two groups of normal conscious rats. LCGU was measured by the [14C]deoxyglucose technique and LCBF by the [14C]iodoantipyrine technique. When the LCGU of 39 brain structures was correlated with their respective values of LCBF an excellent correlation (r = 0.96) was obtained between LCGU and LCBF, demonstrating a tight coupling at a local level. Chronic metabolic acidosis was induced in two other groups of rats by adding 0.35 M NH4Cl to the drinking water for 5-6 days. This resulted in a significant (P less than 0.01) reduction in overall cerebral glucose utilization (-29%) and a nonsignificant reduction in overall cerebral blood flow (-8%). This dissociation between the overall cerebral glucose utilization and blood flow during metabolic acidosis cannot be taken as an indicator of uncoupling because the values for LCGU were still well correlated (r = 0.95) with the values for LCBF, indicating a resetting of the coupling mechanism to a new level.

Acidosis↗
PubMed1980

Formation of indolyl-3-acetylaspartic acid in rats.

Indolyl-3-acetylaspartic acid (IAAsp) was detected in the urine of rats given indolyl-3-acetic acid (IAA) i.p. It was ascertained that the conversion of IAA into IAAsp could be carried out not only in plants but also in animals.

Animals↗
PubMed1970

Induction of pleomorphy and calcium ion deficiency in Lactobacillus bifidus.

The induction of pleomorphism of Lactobacillus bifidus by NaCl was completely inhibited by CaCl(2). When the organism was cultivated in calcium-free medium, growth of the bifid form was exclusively observed. Supplementation of calcium ion in the medium caused bacilloid growth. Chemical analyses indicated that calcium content of the bifid form organisms was significantly less than that of the bacilloid form; i.e., in the former type, there was an approximately 30% decrease of calcium in the whole cells, and an 82% decrease in the cell wall, as compared with the respective content of the latter. These results indicate a suppressing role of calcium ion in the induction of pleomorphism of L. bifidus. Besides calcium content, sugar and amino acid compositions were shown to be different between the bifid and bacilloid forms. In the cell wall especially, the content of glucose in the bifid form was larger than that in the bacilloid form. Methionine and phenylalanine were present in the bifid form, but not in the bacilloid form. Cell walls of the bifid form organisms lacked a larger molecular weight peptidoglycan (7.5S) which was clearly detected in the bacilloid form. Evidence has been given for the relationships of calcium ion and cell wall components to the pleomorphism in L. bifidus.

Amino Acids↗