Effect of blood pressure on the progression rate of renal impairment in chronic glomerulonephritis

An effect of high blood pressure on the progression of renal functional deterioration was studied in 23 cases of chronic glomerulonephritis, which showed progressive renal functional impairments during the long-term follow-up period. The slope-of-regression line, which was obtained from the relation between reciprocal serum creatinine concentration (1/Cr) and observation time, was expressed as a progression rate and was evaluated on an association with blood pressure level. The progression rate was found to correlate significantly with the level of diastolic blood pressure (p less than 0.001). It is concluded that the elevation of blood pressure is one of the factors that contribute to the progression of renal functional impairment in chronic glomerulonephritis.

Role of renin angiotensin aldosterone on minimal change nephrotic syndrome

Plasma volume (PV), plasma renin activity (PRA) and plasma aldosterone (PA) were examined serially at the edema forming stage, the stage of diuresis, and the stage of remission in 11 patients. These patients were steroid responsive, minimal change nephrotic syndrome with normal kidney function. PV was expressed as a percentage of the normal reference value, which was obtained from PV and body height in 44 normal volunteers. PV decreased significantly at the edema-forming stage and increased at the stage of the diuresis. A significant inverse correlation was obtained between PV and PRA. PRA correlated significantly with PA. The amount of 24 hour urinary sodium excretion severely reduced at the edema-forming stage and increased at the stage of diuresis: thus showing a significant inverse correlation with PA. In conclusion, renin-angiotensin-aldosterone system plays a role as a compensatory mechanism to the intravascular volume status in minimal change nephrotic syndrome, but, its' contribution to the genesis of edema is unsusceptible.

Purification and mode of action of a microsomal endoribonuclease from rat liver

An endoribonuclease has been purified nearly to homogeneity from rat liver microsomes, and its mode of action and general properties were studied. The enzyme had an apparent molecular weight of 58 000, as estimated by both gel filtration and SDS-polyacrylamide gel electrophoresis and produced oligonucleotides from poly(A), poly(U) and poly(C). No mononucleotide was obtained by the enzymatic hydrolysis of the above substrates. The enzyme made endonucleolytic cleavages which generated 5'-phosphate-terminated oligonucleotides. It was suggested that the existence of at least (Ado5'P)2 residues at both sides of the cleavage bond was necessary for the action of the endoribonuclease. Divalent cations (Mg2+ or Mn2+) were required for the enzymatic activity, while K+ inhibited the enzyme. Spermine stimulated the enzymatic activity in the presence of 1 mM Mg2+.

Purification and mode of action of a microsomal exoribonuclease from rat liver

An exoribonuclease has been purified nearly to homogeneity from rat liver microsomes and its mode of action and general properties were studied. The molecular weight values for the enzyme, as estimated by gel filtration and SDS-polyacrylamide gel electrophoresis, were 88 000 and 92 000, respectively. The enzyme produced, via a processive mechanism Ado5'P as the only product from poly(A). The results of the hydrolysis of 4 S (Ado5'P)n and (Ado3'P)n by the exoribonuclease with or without alkaline phosphatase and the inhibition of the enzymatic activity by oligonucleotides having a 3'-phosphate group in the 3'-terminus suggested that the degradation proceeds in the 3' to 5' direction. These findings were confirmed by the analysis of hydrolyzed products of various oligoadenylates and Ado3'PUrdPGuo and by the comparison of the rates of hydrolysis of (Ado3'P)2Ado by the enzyme in the presence of varying amounts of (Ado3'P)3. Mg2+ was required for the enzymatic activity, and Mn2+ partially substituted for Mg2+. The activity of the enzyme was stimulated by K+ and spermine.

Developmental changes in components of chick brain microtubule-associated protein-1 (MAP-1) and tau proteins

Microtubule proteins were purified from chick brains at various developmental stages from the 12-day embryo to adult. Three species of microtubule-associated protein-1 (MAP-1) and 5-7 molecular components of tau proteins were observed by SDS-polyacrylamide gel electrophoresis. The molecular compositions were observed to change during development of the chick brain.

gamma-Glutamyltranspeptidase from Proteus mirabilis: localization and activation by phospholipids

Antiserum was prepared against the purified gamma-glutamyltranspeptidase (EC 2.3.2.2) of Proteus mirabilis. The antiserum inactivated the gamma-glutamyltranspeptidase activities of both purified enzyme and intact cells. Native cells were agglutinated with the antibody. Immunocytochemical studies with indirect immunofluorescence and electron microscopy analysis suggested that gamma-glutamyltranspeptidase is localized on the surface of the cell. Its distribution in the cell wall or periplasmic space or both was also confirmed by the treatment of cells with lysozyme-EDTA. The purified enzyme was activated by the addition of membrane phospholipids isolated from the same bacterium. The hydrolysis activity was stimulated more than the transpeptidation activity by several phospholipids.

Purification and properties of gamma-glutamyltranspeptidase from Proteus mirabilis

gamma-Glutamyltranspeptidase was purified ca. 15,200-fold from cell-free extracts of Proteus mirabilis to electrophoretic homogeneity and then crystallized. The enzyme has an estimated molecular weight of 80,000 and consists of two different subunits with molecular weights of ca. 47,000 and 28,000. The purified enzyme catalyzed hydrolysis and transpeptidation of various gamma-glutamyl compounds, including the oxidized and reduced forms of glutathione, gamma-glutamyl compounds of L-phenylalanine, L-tyrosine, L-histidine, L-alpha-aminobutyrate, L-leucine, and p-nitroaniline. Glycylglycine, L-phenylalanine, L-methionine, L-histidine, L-tryptophan, and L-isoleucine were good acceptors of the gamma-glutamyl moiety in the transpeptidation reaction. Km values for gamma-glutamyl compounds were on the order of 10(-4) to 10(-5) M, and those for acceptor peptides and amino acids were on the order of 10(-2) to 10(-3) M. The enzyme was inhibited by L-serine plus borate and 6-diazo-5-oxo-L-norleucine, which are inhibitors of gamma-glutamyltranspeptidases isolated from mammals. Various amino acids alone were found to inhibit the transpeptidation competitively with a gamma-glutamyl donor. Kinetic analysis suggested that the reaction sequence of substrate binding and product release proceeds according to a ping pong bi bi mechanism.

Leakage of glutathione from bacterial cells caused by inhibition of gamma-glutamyltranspeptidase

Glutathione leaked from cells of Proteus mirabilis grown in medium containing an inhibitor of gamma-glutamyltranspeptidase. In medium containing 100 mM L-serine and borate, up to 300 microM glutathione accumulated. L-Serine in the medium was consumed during the logarithmic phase of growth, gamma-glutamyltranspeptidase activity was restored, and glutathione decreased in the medium. In the presence of 2 mM 6-diazo-5-oxo-L-norleucine, cells increased normally, gamma-glutamyltranspeptidase was inhibited completely, and the maximum concentration of glutathione which accumulated in the medium was 20 microM. The glutathione content of cells rose before leakage began. Glutathione leaked from intact cells of other bacteria, although to a lesser extent than was seen with P. mirabilis.

Worsening of anemia induced by long-term use of captopril in hemodialysis patients

During long-term captopril administration to hypertensive patients on maintenance hemodialysis, a decrease in hemoglobin, hematocrit, and red blood cell count was observed in 9 out of 12 cases. The maximum decrease in hemoglobin, on the average, was detected after 10.9 months of captopril treatment, when the average decrease was 20.5%. The average daily dose of the drug was 27.6 mg/day throughout the observation period. Mean corpuscular constants, reticulocyte count, serum iron, and total iron-binding capacity did not change significantly. Coombs' test was negative. Neither serum total protein nor body weight changed significantly. Fever, skin rashes, leukopenia, and eosinophilia were not observed. There was no significant correlation between the degree of decrease in hematological indices and the dose of captopril. After discontinuation of captopril administration, anemia improved to pretreatment levels. In 2 of the 3 patients who did not show worsening of anemia, an anabolic steroid was administered in association with captopril. It is suggested that captopril should be used with caution in hemodialysis patients.

Suppression of proteinuria by dipyridamole in rats with aminonucleoside nephropathy

Nephrosis was induced by single injections of puromycin of aminonucleoside to rats which were divided into two groups; the experimental group receiving dipyridamole in addition to aminonucleoside and the control group receiving aminonucleoside alone. 24-hour urinary albumin increased in rats of both groups after aminonucleoside injections. However, the experimental rats excreted significantly less albumin than controls. On the contrary, there was no significant difference in urinary IgG between the two groups. The stainings of anionic sites of glomerular basement membrane using ruthenium red revealed the reduction of anionic charge in the glomerular basement membrane of both groups, but the decrease of anionic charge was suppressed in lamina rara interna of the experimental rats. Considering the role of charge barrier in the glomerular basement membrane, it is concluded that the maintenance of anionic charge in experimental rats is causally related to the suppressed excretion of albumin.

Carcinogenicity of dipyrone in (C57BL/6 X C3H)F1 mice

The carcinogenicity of dipyrone (sulpyrin)--[(2,3-dihydro-1,5-dimethyl-3-oxo-2-phenyl-1H-pyrazol-4 -yl) methylamino]methanesulfonic acid sodium salt monohydrate--which is widely used as an antipyretic anodyne in Japan and in some European countries, was examined in 314 (C57BL/6 X C3H)F1 mice. Male animals were given 0.5% (group I-a) or 0.125% (group I-b) dipyrone in their drinking water for 78 weeks, and female animals were given 1.0% (group II-a) or 0.25% (group II-b) dipyrone in their drinking water for 78 weeks; both males and females were observed for 86 weeks. Twenty-seven of 48 (56%) group I-a animals and 36 of 44 (82%) group II-a animals developed hepatic tumors, and the tumors in group II-a mice developed earlier than those in the control animals. The tumor incidences were significantly higher than those of 8 of 44 (18%) and 3 of 51 (6%) in the respective control groups. The multiplicity of the hepatic tumors was also significantly increased in groups I-a, I-b, and II-a. Hepatic adenoma incidence was related to the dose of dipyrone in the males. These results show that dipyrone enhances the development of hepatic tumors in mice.

Purification and properties of an endoribonuclease existing as a complex with inhibitor in rat liver cytosol

An endoribonuclease existing as a complex with inhibitor in the cytosol of rat liver has been purified about 128,000-fold after inactivation of the inhibitor with CdCl2. The enzyme had a molecular weight of 16,000 and produced 3'-CMP via 2',3'-cyclic phosphate of cytidine from poly(C). The breakdown of poly(U) by the enzyme was less than 5% of poly(C) breakdown. Poly(A) was not hydrolyzed by the enzyme. The enzyme had a pH optimum of 7.5-8, was heat-stable and had a Km of 952 micrograms yeast RNA and a Km of 198 micrograms poly(C) per ml. The maximal velocities for yeast RNA and poly(C) degradation were 3,970 A260/min/mg protein and 1,890 A260/min/mg protein, respectively. The enzyme was slightly stimulated by polyamines or monovalent and divalent cations except Mn2+, but was inhibited by nucleoside triphosphate, poly(G) and rat liver RNase inhibitor. Inhibition of the enzyme by rat liver RNase inhibitor was not prevented by monovalent and divalent cations or polyamines, although inhibition by poly(G) was prevented by these ions.

A porcine brain protein (35 K protein) which bundles microtubules and its identification as glyceraldehyde 3-phosphate dehydrogenase

A protein which binds to both tubulin and tubulin polymer was isolated from porcine brains. This protein has a molecular weight of 35,000 on SDS-polyacrylamide gel electrophoresis (designated as 35 K protein). The 35 K protein was purified through several steps of purification including ammonium sulfate fractionation, Sephadex G-100 gel filtration column chromatography, microtubule protein-agarose gel affinity column chromatography and phosphocellulose column chromatography. The 35 K protein caused pronounced enhancement of the turbidity increase produced by tubulin polymerization in the presence of DMSO, but did not have the ability to initiate polymerization of pure tubulin in the absence of DMSO. It was demonstrated that 35 K protein co-sediments with tubulin polymer in a concentration-dependent manner. Electron microscopic observation revealed the formation of bundles of tubulin polymer. Since the effect of 35 K protein was coupled with tubulin polymerization, 35 K protein did not cause the turbidity increase under conditions where tubulin polymerization was inhibited by Ca2+ or colchicine. The 35 K protein adsorbed on tubulin-Sepharose 4B was eluted by the addition of 2 mM ATP. ATP was shown to inhibit the interaction of 35 K protein with tubulin dimer or polymer. The 35 K protein was finally identified as glyceraldehyde 3-phosphate dehydrogenase from properties such as mobility on SDS-polyacrylamide gel electrophoresis, cleavage pattern on limited proteolysis, ability to bind to tubulin, and so on.

Studies on salivary gland ribonucleases. III. Purification and properties of three ribonucleases from bovine parotid gland

Three alkaline ribonucleases [EC 3.1.4.22] were purified 4,500- to 7,850-fold from bovine parotid gland by repeated CM-Sephadex C-25 chromatography and Sephadex G-50 gel filtration, with a total recovery of about 33%. They were designated as RNase BP1, BP2, and BP3, based on their order of elution from a CM-Sephadex C-25 column. The molecular weights of these enzymes were estimated by gel electrophoresis to be 18,500, 18,000, and 14,000, respectively. These enzymes are very similar to RNase A in that they are inhibited by heparin, show preferential hydrolysis of C5'-O-P linkages adjacent to a cytosine nucleotide rather than a uracil nucleotide, and in their antigenic properties. Spermine was found to stimulate the activities of these enzymes; the degree of stimulation was in the order of RNase BP3 greater than BP2 greater than BP1. The stimulation by spermine is mainly due to the increased cleavage of C5'-O-P linkages adjacent to cytosine nucleotides. From the results of amino acid analysis, glycosidase digestion and amino-terminal sequencing, it was suggested that the differences in molecular weights of RNase BP1, BP2, and BP3 are due to the differences in carbohydrate contents. In addition, it was suggested that RNase BP3 is identical with RNase A.

Long-term hemodynamic response to captopril (SQ 14,225) in hypertensive hemodialysis patients

The long-term effect of treatment with captopril was observed in 7 hypertensive patients on maintenance hemodialysis who had been refractory to combined antihypertensive therapy with propranolol and hydralazine. Captopril showed a potent hypotensive effect in all the subjects throughout the study period of 6 months. The blood-pressure reduction during treatment with captopril was associated with a decrease in total peripheral resistance. Cardiac index increased significantly due to a significant increment in heart rate at the 6th month. Plasma renin activity increased significantly at the 3rd month, whereas it decreased at the 6th month. No significant correlation was observed between the blood-pressure response and the pre-treatment level of plasma renin activity.

Perianal lesions of BALB/c mice induced by 1,2-dimethylhydrazine dihydrochloride and methylazoxymethanol-acetate: their classification and histogenesis

The histogenesis of perianal squamous cell carcinomas induced by subcutaneous and intraperitoneal injection of 1,2-dimethylhydrazine dihydrochloride (DMH) and painting of methylazoxymethanol (MAM)-acetate on the anal region was investigated in 212 female BALB/c mice. Painting of MAM-acetate and injection of DMH induced similar benign and malignant tumors and hyperplastic lesions in the anal region. In chronological studies on animals given DMH subcutaneously, cystic or solid squamous lesions, foci of immature sebocytes, sebaceous hyperplasias and sebaceous adenomas were identified. These lesions seemed to be precursors of carcinomas that developed in the same region, and originated from hair follicles or sebaceous glands of the pilosebaceous complexes, but not from the anal mucosa. In mice treated with DMH, the incidence of perianal carcinomas was high in groups with high incidences of colon carcinomas.

The interaction between calmodulin and microtubule proteins. IV. Quantitative analysis of the binding between calmodulin and tubulin dimer

We reported previously that calmodulin binds to tubulin in a Ca2+-dependent manner, thereby inhibiting microtubule assembly. In this work, we quantitatively investigated the binding between calmodulin and tubulin by applying two analytical methods. One was the frontal analysis using affinity chromatography originally developed by Kasai and Ishii (J. Biochem. 84, 1061-1069, 1978). The use of tubulin-Sepharose columns gave a dissociation constant of 4.0 microM. The other was the equilibrium gel filtration developed by Hummel and Dreyer (Biochim. Biophys. Acta 63, 532-534, 1962). This method using a Sephadex G-100 column provided a dissociation constant of 3.5 microM under the same medium conditions as in the frontal analysis, and it was found that 2 mol calmodulin could bind to 1 mol tubulin. Furthermore, the frontal analysis method was convenient for studies on the effect of temperature and ionic strength on the binding. Upon elevating the temperature, the dissociation constant increased. Increase in the ionic strength also increased the dissociation constant.

Initial sites of insulin cleavage and stereospecificity of carboxyl proteinases from Aspergillus sojae and Pycnoporus coccineus

Initial cleavage sites of native insulin at a pH of about 3 and stereospecificity were investigated by fungal carboxyl proteinases (EC 3.4.23.6) from ASpergillus sojae, a species of fungi imperfecti, and Pycnoporus coccineus (formerly designated Trametes sanguinea), a wood deteriorating Basidiomycete, respectively. Fungal carboxyl proteinases were used as a model of vertebrate insulin degradation. A. sojae carboxyl proteinase I primarily hydrolyzed two peptide bonds located on the surface of native insulin monomer, the B16-B17 (Tyr-Leu) and B24-B25 (Phe-Phe) bonds, and secondarily the buried bonds, A15-A16 (Gln-Leu), B15-B16 (Leu-Tyr) and B14-B15 (ala-Leu), at pH 3.2 and 30 degree C. The initial cleavage sites of A. sojae carboxyl proteinases I towards native insulin were not identical with the initial cleavage sites towards the oxidized B chain of insulin. P. coccineus carboxyl proteinase Ia selectively hydrolyzed B14-B15 (Ala-Leu), B16-B17 (Tyr-Leu) and B24-B25 (Phe-Phe) bonds in the native insulin at pH 2.7. Based on these findings we suggest that the stereospecificity of the fungal carboxyl proteinases is similar to that of cathepsin D (EC 3.4.23.5), and that the synthesis and degradation of insulin may occur in microorganisms.

Diurnal variation of urinary potassium excretion in chronic renal insufficiency

Diurnal variation of urinary potassium excretion was examined on 10 adult patients with chronic renal insufficiency and 24 control subjects without cardiorenal functional disturbances. The daily cycle of potassium excretion, similar to that in controls, was present but less obvious in chronic renal insufficiency. In the controls, urinary potassium excretion reached a peak in the early morning (5.30 to 7.30) with a minimum in the night (21.00 to 5.30). The morning rise in potassium excretion was associated with increases in urinary sodium excretion, arterial blood pH, and plasma potassium and aldosterone concentrations. Creatinine clearance rate did not change significantly. In renal insufficiency, plasma potassium level and potassium excretion increased in the morning as compared with the night, whereas sodium excretion, the creatinine clearance rate, arterial blood pH and plasma aldosterone concentration did not change. 9 alpha-Fluorohydrocortisone gave rise to markedly enhanced potassium excretion. The findings suggest that the blunted cycle of potassium excretion in renal insufficiency is due, in part, to suppressed diurnal variations of sodium delivery to the distal tubule, acid-base balance and/or aldosterone secretion.

Tumors of the anal region induced in mice painted with methylazoxymethanol acetate

The carcinogenicity of methylazoxymethanol acetate (MAM acetate) was examined in 91 BALB/c mice by painting it on the anal region. Carcinomas and adenomas of the perianal sebaceous gland were induced in 23 of 24 male (96%) and 16 of 30 female (53%) mice and keratoacanthoma developed in one of 24 male mice within 30 weeks after treatment with MAM acetate. Vascular tumors of the liver and fat issue of the abdominal cavity also developed in 16 of 24 male (67%) and 3 of 30 female (10%) mice treated with this drug. Microscopic adenocarcinomas were found in the rectal mucosa of 3 of 24 male mice adjacent to the anorectal junction. The sex difference in the incidence of tumors is briefly discussed.