Koichi Kondo

Pathophysiological role of endothelin in acute renal failure

In conscious rats, the i.v. injection of endothelin (ET) caused an increase in blood urea nitrogen (BUN), an index of renal dysfunction. In the model of acute renal failure which was induced by occlusion of the bilateral renal arteries of rats followed by reperfusion, ET-monoclonal antibody improved the renal function. In this model, ET-antibody also protected the kidneys from renal proximal tubular necrosis and suppressed Ca++-accumulation in necrotic tissues. Plasma ET level increased 5 min and 5 hr and renal ET content did 5 and 20 hr after reperfusion. BUN level increased 5 and 20 hr after reperfusion. These results strongly suggest that the endogenously increased ET may be one of the important deleterious mediators in the pathogenesis of ischemic acute renal failure.

Isolation of fatty acid amide as an angiogenic principle from bovine mesentery

Erucamide (13-docosenamide) was found to be the major bovine mesentery angiogenic lipid as assessed by chorioallantoic membrane (CAM) assay. Two micrograms of this lipid caused angiogenesis in the assay. Angiogenic activity of this naturally occurring lipid was also found by rat corneal micropocket and mouse dorsal air-sac assays. Specificity of the chemical structure which elicited activity was low, however. The mechanism of angiogenic activity is unknown and this lipid does not promote proliferation of endothelial cells or induce inflammatory effects.

Endothelin-induced mobilization of Ca2+ and the possible involvement of platelet activating factor and throm☐ane A2

Endothelin (ET) caused transient and sustained elevations of cytosolic free Ca2+ concentrations ([Ca2+]i) in cultured rat and rabbit vascular smooth muscle cells (VSMC). Specific platelet activating factor (PAF) antagonists (CV-6209 and WEB-2086) and arachidonic acid (AA) cascade blockers (chlorpromazine, indomethacin, CV-4151 and AA-2414) potently inhibited the ET-induced increase in [Ca2+]i. Additionally, these compounds inhibited the PAF-induced increase in [Ca2+]i. These results suggest that PAF and thromboxane A2 (TXA2) may be involved in the mechanism of ET-induced mobilization of Ca2+ in cultured rat and rabbit VSMC.

Increase in plasma atrial natriuretic polypeptide (ANP) following sodium load in anesthetized rats

Abstract To investigate the releasing mechanisms of atrial natriuretic polypeptide (ANP), identical amounts of 5% glucose solution, isotonic (0.9%) or hypertonic (5%) saline were infused intravenously for 5 min (2ml/min) in anesthetized rats. At the same time, plasma immunoreactive ANP (ir-ANP) was measured using a direct radioimmunoassay. Plasma ir-ANP increased after infusion of 5% glucose solution (P

Studies of antipyretic components in the Japanese earthworm

Abstract Antipyretic components in the Japanese earthworm ( Lumbricus Spencer, Perichaeta communishima, Goto and Hatai ) were investigated through a study of the antipyretic effect on rabbits having pyrogen-induced fevers caused by Esherichia coli pyrogen and Chromatographic separations. The main proven antipyretic components are considered to be all- cis -5,8,11,14-eicosatetraenoic acid and all- cis -5,8,11,14,17-eicosapentaenoic acid.

Level of Human Chorionic Gonadotrop in-Like Substance in Serum of Normal Subjects

Abstract The level of human chorionic gonadotropin (hCG)-like substance in normal serum was measured using 50 μl of serum specimen by a highly specific and sensitive sandwich enzyme immunoassay for hCG which did not significantly cross-react with hLH. The level was calculated using a standard hCG and expressed in mIU/ml as that of hCG. In normal male (20–59 years of age) and normal, non-pregnant female (20–42 years of age) adults, the level was below 0.6 mIU/ml with mean levels of 0.16 mIU/ml (n=209) and 0.14 mIU/ml (n=36), respectively. In older subjects, however, the level tended to rise. In normal male adults, aged 60–91 years, the level was mostly below 0.8 mIU/ml (mean=0.56 mIU/ml, n=99), but levels of 15 specimens out of 99 were 1.1–5.5 mIU/ml. In normal, non-pregnant female adults, aged 45–88 years, the level was widely distributed between 0.1 and 11.7 mIU/ml (mean=1.6 mIU/ml, n=141). In these older female adults, levels of hCG-like substance were not well correlated to either levels of hLH and hFS...

Establishment of monoclonal antibodies against human acidic fibroblast growth factor

Four kinds of hybridomas secreting monoclonal antibodies (MAbs) against human acidic fibroblast growth factor (haFGF) were established using recombinant haFGF as an immunogen. The recognition sites of four MAbs designated AF1-52, 81, 114 and 1C10 for the haFGF molecule were examined by binding studies with synthetic polypeptides and with amino-terminal truncated forms of haFGF. These experiments suggested that AF1-52, 114, and 1C10 MAbs recognize epitopes within the 1-5, 44-132 and 6-43 amino acid sequences, respectively. However, the epitope recognized by the AF1-81 MAb could not be determined. The sandwich EIA method constructed with these MAbs was sensitive to 1.5 pg/well of haFGF and had no cross-reactivity with human basic FGF, bovine aFGF or the hst-1 gene product.

Analytical studies of maridomycin II. Separation of 9-propionylmaridomycins by thin-layer chromatography

Priopionyl derivatives of maridomycins, 9-propionylmaridomycins (PMDMs), are sixteen-membered ring macrolide antibiotics of six analogous components: I, II, III, IV, V and VI. The present paper deals with the separation and quantitative analysis of these components. The analysis was performed by thin-layer chromatographic separation, addition reaction of gaseous iodine with PMDMs on the plate, extraction of the PMDM-iodine complexes, and subsequent analysis of the amount of reacted iodine, using an automatic analysis system. To ascertain the reaction product of this system, PMDM III-iodine complex was synthesized separately under a liquid-phase reaction and the ratio of PMDM III and iodine atoms was determined to be 1:3 on physicochemical examination.

Enzyme immunoassay of a β-adrenergic agent using β-galactosidase as label

Abstract Antisera against tetrahydronaphthalenols, which are conformationally rigid derivatives of adrenergic catecholamine, were produced in rabbits immunized with trans-5-amino-6-hydroxy-2-isopropylamino-1,2,3,4-tetrahydronaphthalene-1-ol (I) conjugated to succinylated bovine serum albumin at the C5 position on the tetralin ring. Antisera were screened by immunodiffusion and further characterized by passive hemagglutination assay using erythrocytes sensitized with trans-I-ovalbumin conjugate and by enzyme immunoassay using trans-I-β-galactosidase conjugate. Cross-reactivity studies indicated that the antiserum was highly specific for the tetralin structure and for substitution at the C2 position. The antiserum also selectively discriminated the stereoisomers about the C1C2 bond. The anti-trans-I serum was used to develop EIA for trans-5-hydroxymethyl-6-hydroxy-2-isopropylamino-1,2,3,4-tetrahydronaphthalene-1-ol (IIb), which exhibited strong β-stimulating activity fairly selective to tracheal muscle, since it recognized trans-IIb to the same degree as trans-I. The assay could detect as little as 100 pg of this compound. The mean recovery of trans-IIb added to plasma was 105%, and values for plasma trans-IIb determined by this immunoassay correlated well with those determined by gas chromatography-mass spectrometry.