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S Kim

Publications and source records attributed to S Kim.

At least 1,261 records · Page 70Linked to original sources
PubMed1988

Multiple small molecular weight GTP-binding proteins in bovine brain cytosol. Purification and characterization of a 24KDa protein.

We have separated multiple small Mr GTP-binding proteins (G-proteins) from bovine brain crude membranes, purified a novel 24KDa G protein (smg p25A) to near homogeneity and characterized it. In this paper, we have studied these small Mr G proteins in the cytosol fraction of bovine brain. [35S]GTP gamma S-binding activity is detected in the cytosol fraction but this activity is one-sixth to one-eighth of that of the crude membrane fraction. When G proteins in the cytosol fraction are purified by successive chromatographies on DEAE-cellulose, Ultrogel AcA-44, hydroxyapatite and Mono Q HR5/5 columns, multiple small Mr G proteins are separated. One of these G proteins shows a Mr of about 24KDa. Its physical, immunological and kinetic properties are indistinguishable from smg p25A. These results indicate that there are also multiple small Mr G proteins in the cytosol fraction of bovine brain, and suggest that one of the cytosol G proteins is the soluble form of smg p25A.

Animals↗
PubMed1988

[Immunoreactive parathyroid hormones in the circulation and cerebrospinal fluid from patients with renal failure: possible restriction of parathyroid hormone by the blood-brain barrier].

There are reports that patients with renal failure have elevated circulating concentrations of parathyroid hormone (PTH), which is suspected to be a causal factor of the cerebral symptoms of these patients. A positive correlation between the circulating level of immunoreactive PTH and the extent of abnormality in the electroencephalogram (EEG) in humans has been reported. Moreover, in uremic dogs normalization of the EEG was observed after parathyroidectomy, and increased abnormality of the EEG was observed on infusion of PTH. If PTH is really a causal factor of uremic encephalopathy and abnormality of the EEG in patients with renal failure, the question arises as to whether PTH acts on the brain after penetrating through the blood-brain barrier or in some other way. In this work, we measured PTH by both C-terminal-specific RIA (C-PTH) and N-terminal-specific RIA (N-PTH) in the circulation and cerebrospinal fluid (CSF) of normal subjects and patients with renal failure. Blood and CSF samples were obtained from 7 normal volunteers (31 approximately 81 years old: 4 males and 3 females) and 22 patients with chronic renal failure (25 approximately 87 years old: 12 males and 10 females). No patients had a psychotic disease or endocrinopathy other than secondary hyperparathyroidism. Samples of venous blood were collected from the subjects after an overnight fast at the time of lumbar puncture for CSF sampling. C-terminal-specific RIA for measurement of the plasma and CSF concentrations of C-PTH was carried out using a commercially available RIA kit (Eiken Laboratory Inc., Tokyo, Japan).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Determination of methylated amino acids in human serum by high-performance liquid chromatography.

Employing high-performance liquid chromatography with isocratic elution using a two-column system (mu Bondapak C18 and mu Bondapak CN) and phenyl isothiocyanate as a fluorogenic reagent, NG-monomethylarginine (MMA). NG-dimethylarginines, and epsilon-N-trimethyllysine (TML) can be quatitatively separated from human serum samples. The recoveries of these amino acids were over 90%. It was observed that the serum concentrations of MMA, DMA and TML were significantly elevated in sera obtained from patients suffering from diabetes mellitus, hepatitis or hyperthyroidism, particularly the last condition.

Amino Acids↗
PubMed1988

Biphasic pulp blood-flow response to substance P in the dog as measured with a radiolabelled, microsphere injection method.

A dose of the vasoactive substance P (SP), affecting local circulation only (0.0001-0.001 micrograms/kg body weight) when given by a close injection into the maxillary artery, caused a biphasic flow response in pulpal blood flow (PBF), as measured by a radioisotope-labelled 15 micron microsphere injection technique. Immediately after the SP injection, PBF increased some 66 per cent (p less than 0.02) and vascular hindrance (Z) decreased to 40 per cent against control values (p less than 0.02), indicating vasodilation. Thirty seconds after the SP injection, PBF decreased by 53 per cent (p less than 0.05), and pulpal Z increased 139 per cent against control values (p less than 0.02), indicating decreased blood flow. This biphasic flow response may be due to the active vasodilation of arterioles by SP, which causes a compression of venules and hence a reduction of PBF in what is a low-compliance system.

Animals↗
PubMed1988

Interrelationship between nuclear histone binding and cell proliferation.

1. Binding of non-enzymatically [methyl-14C]-labeled histone H3 to nuclei isolated from young and old rat livers, regenerating rat liver, and tumor cells has been investigated. 2. Scatchard plot analysis indicated that various cell types had different binding capacity and different dissociation constant (Kd). 3. Nuclei isolated from younger rats had fewer binding sites and lower Kd (or higher Ka) values for [methyl-14C]H3 than those from older rats. 4. Fewer binding sites and lower Kd values were also observed with nuclei isolated from the maximally regenerating liver (24 hr after partial hepatectomy) and the fast-growing ascites tumor and Novikoff hepatomas. 5. These results strongly suggest that the number of binding sites and affinity of histone H3 for nuclei appears to be correlated with the degree of cell proliferation. 6. Fractionation of the [methyl-14C]H3 bound nuclei into nuclear membrane and nucleoplasm demonstrates that approx. 94% of radioactivity is associated with the former in which less than 6% of DNA is found, whereas 94% of total DNA is found in nucleoplasm. 7. This suggests that the binding of [methyl-14C]H3 to nuclei is independent of DNA present in each fraction.

Aging↗
PubMed1988

Heterogeneity of glycosylation of circulating active and inactive renin.

Concanavalin A chromatography was used to examine rat plasma and the incubation medium of rat renal cortical slices, the objective being to assess the heterogeneity of glycosylation of active and inactive renin. Inactive renin was measured by activation with trypsin. Concanavalin A chromatography could separate both active and inactive renin in the plasma into three forms, including the unbound form, the loosely-bound form and the tightly-bound form, thereby suggesting the presence of differently glycosylated forms of active and inactive renin in the plasma. Rat renal cortical slices secreted all these three forms of active and inactive renin, hence these forms are mainly of renal origin. These results suggest that differently glycosylated forms of active and inactive renin are released from the kidney into the blood circulation.

Animals↗
PubMed1988

Planar and SPECT Tc-99m red blood cell imaging in hepatic cavernous hemangiomas and other hepatic lesions.

The utility of Tc-99m RBC imaging in the diagnosis of hepatic cavernous hemangiomas has been established. Of the 25 patients with various focal hepatic lesions evaluated, 16 were diagnosed as having hemangiomas: eight proven by surgery, two proven by angiography, and six proven by maintaining a stable clinical course ranging from 6 to 12 months with normal follow-up liver function tests. Although fourteen of these were detected by planar imaging, two were detected by SPECT only. Two patients with large hemangiomas had false-negative scans, whereas the remaining seven patients had other liver lesions.

Adult↗
PubMed1988

Effect of changes in sodium balance on renin, angiotensinogen and atrial natriuretic factor messenger RNA levels in rats.

The expression of messenger (m)RNA for renin, angiotensinogen and atrial natriuretic factor (ANF) was investigated in rats on different sodium intakes. Messenger RNA was measured by a radiodensitometric hybridization assay. In the high-sodium state, renal renin mRNA decreased, but it increased in the low-sodium state. A further increase in renin mRNA was seen in the low-sodium state after captopril administration. Angiotensinogen mRNA levels in the liver, kidney and brain were altered by varying sodium intake. In the high-sodium state angiotensinogen mRNA decreased, but in the low-sodium state it increased. After treatment with captopril, angiotensinogen mRNA levels decreased in the liver and kidney. Angiotensinogen mRNA showed tissue specificity for expression, especially in the brain. Atrial ANF mRNA levels changed slightly with different levels of sodium intake.

Angiotensinogen↗
PubMed1988

Differently glycosylated multiple forms of renin in the blood circulation of rats.

Serial lectin chromatography of rat plasma on concanavalin A and lentil lectin columns separated plasma renin into differently glycosylated multiple forms. To study the role of glycosylation in the clearance of circulating renin, three different forms of glycosylated renin (renin A, B-1 and B-2) were highly purified from rat kidneys. Renin A and B-1 were loosely and tightly, respectively, bound to concanavalin A, but did not bind to lentil lectin. Renin B-2 was bound to both concanavalin A and lentil lectin. Each form of renal renin, labelled with 125I and intravenously given to rats, disappeared from the blood circulation at different rates, and distributed in the liver and kidney to different extents. Deglycosylation of renin B-1 with endoglycosidase F led to reduced metabolic clearance rates and to a significant decrease in uptake by the liver. These results show the heterogeneity in the fate of circulating renin due to the heterogeneity of glycosylation.

Animals↗
PubMed1988

Sodium balance effects on renin, angiotensinogen, and atrial natriuretic polypeptide mRNA levels.

The expressions of the renin, angiotensinogen, and atrial natriuretic polypeptide (ANP) genes were studied in rats with varying sodium intakes. mRNAs for angiotensinogen and renin were measured by a sensitive radiodensitometric hybridization assay. ANP mRNA was determined by a dot-blot hybridization assay. In the high-sodium state, plasma renin concentration (PRC), renal renin concentration (RRC), and renal renin mRNA decreased by 88, 90, and 75%, respectively. In the low-sodium state, PRC, RRC, and renin mRNA increased 17-fold, 2.5-fold, and 4.5-fold, respectively. With captopril treatment during sodium depletion, PRC and renin mRNA increased 144-fold and 17.1-fold, respectively, and RRC increased 4.2-fold. The angiotensinogen mRNA level in the liver and kidney decreased in the high-sodium and increased in the low-sodium state to similar extents. Captopril treatment decreased angiotensinogen mRNA in both organs by about half. Plasma ANP and ANP mRNA decreased in the low- compared with the high-sodium state, whereas atrial ANP content was unaltered in both low- and high-sodium states. These results demonstrate that sodium intake affects the expression of the renin and angiotensinogen genes and slightly alters the expression of ANP gene.

Aldosterone↗
PubMed1988

Importance of glycosylation for hepatic clearance of renal renin.

Three differently glycosylated forms of renin (renin A, B-1, and B-2) were highly purified from rat kidneys by pepstatin-aminohexyl-Sepharose affinity chromatography and by serial lectin affinity chromatography on concanavalin A (con A) and lentil lectin-Sepharose, and the role of glycosylation of renin was investigated. Renin A and renin B-1 were loosely and tightly bound to con A, respectively, but did not bind to lentil lectin. Renin B-2 bound to both con A and lentil lectin. These three forms of renin were all similar in their physicochemical characteristics, including molecular weight, isoelectric point, specific activity, Km, optimum pH, and antigenicity. Each form of renin, labeled with 125I and given intravenously to anesthetized rats, disappeared from the circulation at different rates (metabolic clearance rates of 5.05 +/- 1.02, 17.1 +/- 2.5, and 36.0 +/- 4.1 ml.min-1.kg-1 for renins A, B-1, and B-2, respectively). Labeled renin A distributed to a similar extent in the liver and kidney (21.2 +/- 0.2 and 15.2 +/- 0.8% of the injected dose, respectively), whereas renins B-1 and B-2 were distributed predominantly in the liver (56.3 +/- 1.2 and 72.3 +/- 3.7% of the injected dose, respectively) and to a lesser extent in the kidney (4.3 +/- 0.3 and 2.1 +/- 0.2%, respectively). Deglycosylation of renin B-1 with endoglycosidase F resulted in no loss of its enzymatic activity or antigenicity but greatly reduced the metabolic clearance rate to 18% (from 17.1 +/- 2.5 to 3.09 +/- 0.17 ml.min-1.kg-1). Deglycosylation of renin B-1 greatly decreased its uptake by the liver (from 56.3 +/- 1.2 to 3.3 +/- 0.2%) and increased its uptake by the kidney (from 4.3 +/- 0.3 to 23.9 +/- 0.9%). These studies indicate the importance of glycosylation of renin for its hepatic uptake and metabolic clearance rate.

Animals↗