Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.4 (ribonuclease)
 6,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Five ribonuclease activities, separable by polyacrylamide gel electrophoresis, have been detected in erythroid bone marrow cells from anaemic rabbits. Their intracellular distribution has been investigated and compared with that of the ribonucleases in reticulocytes. Both the acid and alkaline ribonuclease activities of reticulocytes are much lower (30--50 fold) than those of bone marrow erythroid cells. The most marked decrease in enzyme activity occurs in the fractions containing ribosomes and mitochondria plus lysosomes. In these subcellular organelles there was also a qualitative change in the ribonuclease electrophoretic pattern, whereas the cytosol enzymes of marrow erythroid cells and reticulocytes remained largely unchanged. Several ribonucleases released from reticulocyte membranes with urea were similar to those present in the lysosomal plus mitochondrial fraction, as shown by detection of enzyme activity after polyacrylamide gel electrophoresis. The decline in ribonuclease activity was found to begin in the orthochromatic cells, which have a highly condensed nucleus and are no longer active in DNA and RNA synthesis, and to coincide with a decrease in acid phosphatase activity and loss of lysosomes.
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PMID:Intracellular distribution of ribonuclease activity during erythroid cell development. 1 51

In an effort to develop a sensitive and specific method for detecting human prostatic cancer at early stages, we have studied the isoenzyme patterns of acid phosphatase in patients' sera as well as in benign hypertrophic and cancerous prostatic tissues using isoelectric focusing techniques. At least eight acid phosphatase isoenzymes at pI 4.1-5.5 could be observed. The sera with highly elevated acid phosphatase activity generally contained more isoenzymes with pI values of 4.5-5.0. The purified acid phosphatase isolated from benign hypertrophic and malignant prostatic tissues showed no qualitative difference in isoenzyme patterns although quantitative variations were observed. Malignant tissue contained more isoenzymes with pI values of 4.5-4.8. Patients' sera were found to contain isoenzymes of prostate origin. We have also investigated serum ribonuclease (RNase) activity in patients with prostatic cancer. The serum RNase activity of patients was significantly elevated. No significant correlation was observed between serum acid phosphatase and RNase activity. In some instances, where acid phosphatase activity was in the normal range, RNase activity was elevated. These data suggest that simultaneous measurements of RNase and acid phosphatase activities may be of value in the diagnosis of prostatic cancer. The purified RNase has been isolated from human prostatic tissue and its immunologic properties are being studied.
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PMID:Enzyme markers in human prostatic carcinoma. 6 22

The activity and sedimentation of acid phosphatase (APase), acid deoxyribonuclease (DNase), and acid ribonuclease (RNase) were investigated throughout growth and encystment in Acanthamoeba castellanii. The activities/mg protein of all 3 hydrolases are high in young cultures and decrease to constant levels in postlog cells. The RNase activity/ameba decreases 50% during growth, whereas the activity/cell of both APase and DNase remains constant. The percent sedimentation at 20,000 g of all 3 enzymes gradually increases from about 40% in midlog to a plateau of 80% in postlog cells. During encystment, the sedimentation behavior of RNase differs from that of APase and DNase. Encystment is characterized by a differential decrease in the activity/cell of the 3 hydrolases, with RNase decreasing most rapidly and APase least rapidly. APase is unique in that a transient increase of its specific activity is noted during encystment, even though its activity/cell is decreasing.
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PMID:Acid hydrolase activity during growth and encystment in Acanthamoeba castellanii. 18 46

The activity of certain enzymes of energy metabolism (cytochrome c oxidase, citrate synthase, malate dehydrogenase, and lactate dehydrogenase) and of lysosomes (beta-glucuronidase, beta-N-acetylglucosamindase, arylsuphatase, ribonuclease, deoxyribonuclease, acid phosphatase, and cathepsin D) was assayed from m. rectus femoris of mice trained 5 days per week, 1 hr per day for 4 weeks according to 4 different programmes: I. running speed 20 m/min, horizontal track, II. 25 m/min, horizontal track, III. 20 m/min 8 degrees uphill inclination, and IV. 25 m/min 8 degrees uphill inclination. Oxidative capacity increased and anaerobic capacity decreased without distinction between the different traning programmes. Of acid hydrolases assayed the activities of beta-glucuronidase and cathepsin D were increased independently of training intensity. Simultaneous histochemical observations on beta-glucuronidase and arylsulphatase activities in the contralateral m. rectus femoris showed more intense staining in red as compared to white muscle fibres. It is suggested that training affected the red fibres and that the applied level of loading was probably too low to cause major involvement of white fibres.
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PMID:Oxidative and lysosomal capacity in skeletal muscle of mice after endurance training of different intensities. 21 99

Studies were undertaken on the turnover of ribosomal RNA and on ribonuclease activity in the liver of the pregnant rat in an attempt to explain the accumulation of liver RNA which occurs during the latter half of pregnancy. Between the 15th and 20th day of gestation the rate constant of degradation, biological half-life and daily rate of synthesis of ribosomal RNA were calculated to be 0.0887, 7.81 days and 6.21 mg per liver per 100g body weight respectively. Corresponding values in non-pregnant rats were 0.123, 5.68 days and 3.47 mg per liver per 100g body weight. The increase in RNA was therefore associated with an increase in its rate of synthesis and a decrease in its rate of breakdown. From the 14th day of pregnancy there was a decrease in alkaline ribonuclease activity and a marked increase in the level of alkaline ribonuclease inhibitor. The activity of acid ribonuclease was found to increase and that of acid phosphatase to decrease during this period.
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PMID:Ribosomal RNA turnover and the level of ribonuclease activity in the liver of the pregnant rat. 23 89

Cytochemical methods are used to examine the distribution and localization of acid phosphatase, non-specific esterase, ribonuclease and peroxidase activity in the walls of the spores of the heterosporous Marsileaceae before and during germination. In the quiescent spore, the principal activity is associated with the perine layer of the wall and the intine, with some activity in the outer, gelatinous wall layer, but none in the exine. The microspores of Marsilea and Pilularia have non-specific esterase activity concentrated in the intine inthe immediate vicinity of the germinal site; that is, above the position of the future male gametangia. The enzymes are not leached from the wall during hydration of the spores, although ribonuclease is redistributed during imbibition with a high concentration of activity remaining in or around the germinal site. The wall enzymes occur together with PAS-reactive and acidic carbohydrates, lipids, and in the microspore perine, beta-lectins. Following the enzyme pattern, the beta-lectins are found to be concentrated in the region of the germinal site. beta-Lectin activity is absent from the megaspore wall. Acidic carbohydrates are confined to the gelatinous wall layer and this layer also binds concanavalin A. In contrast to what has been found for other plant cells, the spore-wall beta-lectins are not water-labile; the activity is not significantly diminished after hydration. This surprising stability suggests that these molecules, together with the enzymes, may be retained in position in the wall by the waterproof overlay of lipid. From the evidence of preliminary developmental studies, it appears that the enzymes associated with the perine layer of the wall originate in the sporophytic tapetal periplasmodium and inclusion of the activity is concurrent with wall differentiation, while the activity associated with the intine is derived from the gametophyte. It is possible, however, in the megaspore at least, that the distribution of the activity may to some extent be influenced by a system of exine channels which communicates between the two domains of the wall during sporogenesis. No definite information is obtained concerning the utility of the enzymes and associated molecules in the life of the spore. Acting separately or in co-operation, their role could conceivably be connected with one or more of four processes; wall differentiation, gametophyte nutrition, gametophyte protection or reproduction. Each of these possibilities is discussed.
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PMID:Developmental mechanisms in heterospory: cytochemical demonstration of spore-wall enzymes associated with beta-lectins, polysaccharides and lipids in water ferns. 52 75

After inducing experimental ileus in albino rats, the authors found changed lysosome enzyme activities in liver homogenizate. In the same kind "free" activity of acid phosphatase and acid ribonuclease is elevated by strangulation ileus. According to literature, these alterations result from changed permeability of lysosome membranes, resp. from rupture of lysosomes. Ileus by obstruction causes no significant changes of the "free" lysosomes activities in liver homogenizate. Increase of acid phosphatase and ribonuclease in blood serum by strangulation or obstruction is equally considerable in both kinds of ileus. The results of these experiments suggest the developing of hepatic damage under both kinds of experimental ileus, the extent of which can be assessed by determination of lysosome enzyme activities.
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PMID:[Changes in the activity of lysosomal enzymes in experimental ileus]. 99 75

The enzymes from the venom of Heterometrus scaber, the indole compounds present and the toxic protein of the venom have been studied. The venom contains acid phosphatase, ribonuclease, 5'-nucleotidase, hyaluronidase, acetylcholine esterase and phospholipase. A. The indole compounds present in the venom have been identified as 5-hydroxytryptophan, tryptophan, serotonin and tryptamine, along with two unidentified indole compounds. The venom produces hyperglycaemia in sublethal doses and this has been found to be due to increased adrenaline secretion. The toxic protein of the venom has been obtained in a pure form by (NH4)2SO4 fractionation, followed by fractional precipitation with acetone and chromatography over DEAE-Sephadex. The toxic fraction has been found to be homogeneous on acrylamide gel electrophoresis. It is a glycoprotein (molecular weight 15 000) containing 1.74% glucosamine, 0.87% galactosamine, 0.313% sialic acid, 3.25% fucose and 0.45% of an unidentified neutral sugar. It did not show any enzyme activities, haemolytic activity or inhibition of succinate dehydrogenase activity but it produced hyperglycaemia in sublethal doses. The toxic level (intravenous administration in rats) was found to be 0.72 mg/kg body weight.
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PMID:Investigations on the venom of the South Indian scorpion Heterometrus scaber. 111 82

Histological and histochemical aspects of the whole encephalic ventricular system of eight specimens of Bradypus tridactylus were studied. After anesthesia and perfusion, the encephalons were obtained by craniotomy. Transverse serial sections of the encephalon, stained according to Azan (Heidenhain's method) or Kluver-Barrera for nerve cells and myelinated nerve fibers; silver impregnation was carried out according to Cajal-De Castro's or Palmgren's methods. The following histochemical reactions were used: PAS (McManus), metachromasia, acid phosphatase (Gomori), Brachet's and Gomori's trichromic reaction (modified by Bargmann for neurosecretion). Histologically, different characteristics of the ependymal cells in different areas were observed, which would be related to functional peculiarities of each area of the encephalic ventricles. The ependymal cells showed discrete apical basophilia due to the presence of RNA which disappears after treatment with crystalline ribonuclease. The PAS reaction indicated the presence of a small quantity of PAS-positive substances in the apical zone of the ependymal cells and the subependymal tissue. These substances disappeared after the salivary amylase test, indicating the presence of glycogen. The acid phosphatase reaction was negative.
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PMID:Histological and histochemical study on the ependyma of Bradypus tridactylus. 116 4

Mediators released from injured human skin that initiate the inflammatory response have not been adequately identified. Organ culture of full-thickness skin explants enables us to do so, because injury to the skin can be made in vitro, eliminating the rapid leakage of serum and infiltration of leukocytes that occur in vivo. In our studies, the military vesicant sulfur mustard (SM) (10 microliters of a 0.01 to 1.0% dilution) was topically applied to injure the epidermis of the explant. Then, the explants were cultured in small Petri dishes, usually for 18 h at 36 degrees C, and the organ-culture fluids were assayed for various inflammatory mediators. We found that the culture fluids from SM-exposed and control explants contained similar amounts of angiotensin-converting enzyme, trypsin-like and chymotrypsin-like proteases, acid phosphatase, beta-glucuronidase, beta-galactosidase, lysozyme, deoxyribonuclease, ribonuclease, interleukin 1, and lactic dehydrogenase. However, the culture fluids from SM-exposed explants contained increased amounts of histamine and plasminogen-activating activity, and often prostaglandin E2, when compared to culture fluids from control explants. After 3 to 4 d in culture, full-thickness human skin explants, when exposed to 0.2% SM (but not when exposed to 1.0% SM), sometimes showed separation of the epidermis and increased collagenase activity (i.e., hydroxyproline release). Thus, histamine (from local mast cells), and prostaglandin E2 and plasminogen-activating activity (probably from both mast cells and epidermal cells) are apparently involved in early mediation of the inflammatory response.
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PMID:Mediators, initiating the inflammatory response, released in organ culture by full-thickness human skin explants exposed to the irritant, sulfur mustard. 171 Jun 39


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