Deoxypentose Nucleic Acid Research Articles

Synthesis of deoxypentose nucleic acid in liver cell of rat following plasmopheresis.

Synthesis of deoxypentose nucleic acid in liver cell of rat following plasmopheresis.

Changes in the concentration of nucleic acids in the aorta of rats in relation to body weight

Summary Pentose nucleic acid phosphorus (PNA-P) and deoxypentose nucleic acid phosphorus (DNA-P) have been determined in the aorta and the diaphragmatic muscle of male rats. Animals weighing between 60 and 290 g were studied. The aortic con centration of both nucleic acids increased with body weight while the P/D ratio decreased. No modifications were observed in the diaphragm. The water content was similar in the aorta as well as in the diaphragm throughout this range of body weight. Histologic findings suggest that the changes observed in the aorta may be totally or partially explained through lymphocytic infiltration of the inner avdentitia. The possible significance of these observations is discussed.

DNA, PNA AND PROTEIN CONTENTS IN A RAPIDLY DIFFERENTIATING SYSTEM, THE RAT TAPEWORM (HYMENOLEPIS DIMINUTA).

THE role of the nucleic acids, deoxypentosenucleic acid (DNA) and pentosenucleic acid (PNA), in the growth and differentiation of organisms has been thoroughly examined and characterized. Rapidly growing tissues usually display rapid synthesis of DNA, PNA and protein. The synthetic rate of these constituents in a given tissue may be estimated by the relative amount of each present. Most of the systems that have been investigated in this regard have required the use of several different individual preparations at different stages of development. Tapeworms, such as Hymenolepis diminuta, should be ideal organisms for the examination of certain principles of growth and differentiation, for along the length of the strobila is a gradient of developmental stages, all within the same individual. The experiments reported in this communication were designed to test the usefulness of the tapeworm in a typical examination of growth and development.

EFFECT OF ETHAMBUTOL ON CYTOLOGY OF MYCOBACTERIUM SMEGMATIS.

Gale, Glen R. (Veterans Administration Hospital, Durham, N.C.) and Helen H. McLain. Effect of ethambutol on cytology of Mycobacterium smegmatis. J. Bacteriol. 86:749-756. 1963.-Electron microscopy showed the effects of the antimycobacterial drug, ethambutol [d-2,2'-(ethylenediimino)-di-1-butanol], on the cytology of Mycobacterium smegmatis. After 10 hr of exposure to the drug, cells no longer contained material which, in control cells, was closely associated with cellular division, possibly genetic substance. No marked changes were observed in other cellular structures. It was concluded that the drug may block one or more steps in the synthesis of pentose nucleic acid or deoxypentose nucleic acid, ultimately causing cessation of cellular division and loss of viability. These cytological findings were compatible with results of other investigators on the mode of action of this drug.

Changes in the aortic concentration of nucleic acids induced by gonadectomy in rats

Summary Nucleic acids were determined as pentose nucleic acid phosphorus (PNA-P) and deoxypentose nucleic acid phosphorus (DNA-P) in the aorta, liver and diaphragmatic muscle of rats. Intact and gonadectomized, male and female animals were studied. Testosterone and estradiol respectively were given to half of the gonadectomized rats. Castration brought about the following changes. In aorta, PNA-P was decreased in male and female animals while DNA-P increased in males and decreased in females; the P/D ratio was lowered in males and elevated in females. In liver, PNA-P was not significantly affected in either sex while DNA-P was elevated in both; nevertheless the P/D ratio was increased in males and depressed in females. In diaphragmatic muscle, both nucleic acid levels were depressed in males and unaffected in females; the P/D ratio showed no changes. These changes show that gonadal hormones have a regulating action on aortic metabolism, and that the action is different from that on other organs.

THE INFLUENCE OF ESTRADIOL ON THE COMPOSITION AND RESPIRATION OF OVIDUCT TISSUE IN THE IMMATURE CHICK

Estrogen administration to the immature fowl, to give oviduct growth rates comparable to those found in the pullet prior to the onset of egg-laying was studied. In a preliminary experiment the level of estradiol required to induce such a growth response in six-week-old chicks was found to be more than 2 mg. administered over a 10-day period. Maximal growth response was produced by 10 mg. estradiol. Two experiments are described in which two levels of estradiol giving growth responses dependent on dose level, i.e. 0.75 mg. and 1.5 mg., are compared with a level of 10 mg. giving maximal response. Oviduct tissues from these experiments were examined for their respiration rate, moisture, protein, fat, pentosenucleic acid and deoxypentosenucleic acid contents, and alkaline phosphatase activity. Moisture content of the tissue decreased with increasing hormone treatment. Fat content increased and on a fresh tissue basis so did protein content. Hypertrophy resulting from 10 mg. estradiol increased the ratio of pe...

ROLE OF SULFUR IN THE CELL DIVISION OF <italic>CHLORELLA</italic>, WITH SPECIAL REFERENCE TO THE SULFUR COMPOUNDS APPEARING DURING THE PROCESS OF CELL DIVISION. I.

The role of sulfur in the cell division of Chlorella was studied by following the fate of the sulfur supplied to the sulfur-deficient cells using 35S as a tracer. The sulfur-deficient cells which were unable to perform cell division were made capable of division by the provision of 36S-labeled sulfate under non-photosynthesizing conditions. Soon after the provision of sulfate the labeled sulfur went rapidly into the cold perchloric acid (PCA)-soluble fraction of algal cells, almost entirely in the form of sulfate and/or some other inorganic sulfur substance (s). With the lapse of time, more or less remarkable changes occurred in the pattern of 35S-distribution in different fractions of cell material. It was noticed that, at the onset of cell division, a sulfur-containing peptide-nucleotide compound(s) (SPN), which has been reported earlier, appeared in a large quantity in the cold PCA-soluble fraction, and that its quantity decreased gradually during the subsequent process of cell division, suggesting that the compound was transformed into some other substance (s), presumably with its nucleotide moiety going into nucleic acids and the peptide moiety going into some essential proteins. Another noteworthy phenomenon observed during the process of cell division was the incorporation of 36S in a group of hot PCA-soluble substances. These sulfur substances were revealed to be sulfur-containing nucleotidic compounds, which might possibly be some essential components of, or substances in close relation to, deoxypentose nucleic acid (DNA).

Effect of S-(dichlorovinyl)-L-cysteine on incorporation of precursors into deoxypentose nucleic acid of leukocytes.

Summary1. When sodium P32-phosphate was injected intravenously into calves, there was an early labeling of leukocyte DNA. 2. DCVC decreased but did not abolish this uptake of P32 when given concurrently with P32 or when calves were pre-treated with DCVC for 2 or 4 days. 3. When normal calf blood was incubated in presence of H3-thymidine, there was a rapid nuclear uptake by mononuclear leukocytes. 4. DCVC did not inhibit incorporation of H3-thymidine in either blood from DCVC-treated calves or in normal blood incubated in presence of DCVC. 5. Abolishment of DNA synthesis in leukocytes or leukopoietic tissue does not appear to be a primary biochemical lesion through which DCVC induces fatal blood dyscrasia in calves.

Partial chromatographic separation of pentose- and deoxypentosenucleic acids.

From a mixture of tobacco mosaic virus pentosenucleic acid (RNA) and calf thymus deoxypentosenucleic acid (DNA) (2 mg each), 73 percent of the RNA was separated free of DNA by discontinuous elution chromatography with phosphate buffers at pH 6.7 on columns of calcium phosphate.

Studies on nucleoproteins VI. The deoxyribonucleoprotein and the deoxyribonucleic acid of bovine tubercle bacilli (BCG)

The preparation of a deoxyribonucleoprotein from the BCG variant of bovine type tubercle bacilli is described. The principal steps involved precipitation at pH 4.2, removal of contaminating materials at half-saturation with ammonium sulfate, and fractionation with ethanol at a low temperature. The purified product was shown to contain about 0.4 amino acid residue for one nucleotide residue. An approximate estimation of the principal amino acids contained in the nucleo-protein revealed a preponderance of dicarboxylic over basic amino acids. The deoxyribonucleic acid was freed of its protein component by tryptic digestion and examined with respect to the distribution of purines and pyrimidines. It belongs to the extreme “GC type”. More detailed aspects of the arrangement of nucleotides in the nucleic acid chain were studied through the application of the method of differential distribution analysis, making use of the results of the stepwise acid hydrolysis. The sugar moiety of the deoxypentose nucleic acid was identified tentatively as deoxyribose. The nucleotide composition of the pentose nucleic acid of BCG also was determined.

PHOSPHORUS METABOLISM IN YEAST ACCOMPANYING AN INHIBITION OF CELL DIVISION BY X-RAYS

The phosphorus and nitrogen content of continuously irradiated and nonirradiated yeast cultures was measured at 0, 2, 4, and 6 hr as the cultures grew rapidly for most of this time. Division was completely stopped at a 3.9 kr/ hr X-radiation dose, but not at a 2 kr/hr dose, while growth was reduced relatively little. A striking change in irradiated cells was an increase in acid insoluble polyphosphate at 2 hr. Pentosenucleic acid phosphorus and protein nitrogen on a dry weight basis also increased in irradiated cells as compared to nonirradiated cells. Amounts of phos phorus and nitrogen in the trichloracetic acid extract decreased, as did the phosphorus of the lipid extract. Apparently no reduction in deoxypentosenucleic acid formation had occurred at 2 hr, and thus a effect on this material did not appear responsible for the inhibition of cell division. It is conceivable that the polyphosphate increase was related to the inhibition of this cell function. (auth)

Hormonal influence on the nucleic acid and protein contents of the human myometrium

The protein and nucleic acid contents in human myometrium from women in the post-menopausal period, from non-pregnant women with ovarian function and from pregnant women at different stages of pregnancy have been determined. The deoxypentose nucleic acid content per mg dry weight is very high in the post-menopausal group, reflecting a considerable nuclear density per unit tissue in this state. Ovarian hormone activity causes a moderate decrease in the density in the non-pregnant group and a considerable reduction during pregnancy. Concomitant and reversely proportional to these changes are the findings of small amounts of protein per tissue unit in the post-menopausal uteri, moderately increasing values in the non-pregnant state and relatively very high values during pregnancy. The pentose nucleic acid content per tissue unit is very low in the post-menopausal group, increases under the influence of ovarian hormones and exhibits very high values during pregnancy. The relative increase during the first 20 weeks of pregnancy is more pronounced than after this period. This finding indicates that the main accumulation of PNA in the cell coincides with the period of rapid growth as judged from the weight-increase of the human uterus. During the normal process of hormone-induced growth, represented by this material, the relative increase in protein and PNA per tissue unit is approximately the same, being about 15 times for the protein and 12 times for the PNA.

Interaction between deoxypentosenucleic acid and histone in strong saline

The interaction between DNA and histone in strong saline at neutrality was studied by viscometry and sedimentation measurements. The results obtained with calf thymus nucleohistone and with artificial mixtures of DNA and histone were in good agreement. Viscosity and sedimentation coefficient varied markedly with the sodium chloride concentration, but neither depolymerization nor aggregation of the DNA molecule appears to be involved. In relatively weak saline solution ( e.g., i M NaCl), a complex of DNA and histone I exists, which complex dissociates progressively with increase in salinity. Other strongly basic proteins studied thus far showed practically no interaction with DNA even in relatively weak saline solution, although the mixtures with DNA gave fibrous precipitates of “nucleoprotein” in physiological saline.

Protoplasts of E. coli as sources and acceptors of deoxypentose nucleic acid: rehabilitation of a deficient mutant.

Protoplasts of E. coli as sources and acceptors of deoxypentose nucleic acid: rehabilitation of a deficient mutant.

The expressible fluid of fish fillets. V.—Cell damage in fillets frozen from one side: The general picture

AbstractCell damage, as measured by the escape of deoxypentose nucleic acid (DNA) into the intercellular spaces, was studied in cod fillets frozen from one side at different speeds. Three distinct types of damage were revealed by peaks in the DNA/freezing time curves, at freezing times of about 27, 75 and greater than 125 minutes. Microphotographs of the muscle frozen in about 75 minutes showed that at this rate of freezing the changeover from intra‐ to extra‐cellular freezing was occurring. In fillets frozen from both sides it had previously been found that these conditions gave rise to much DNA escape. The other two types of damage are to be discussed later.

The role of the Krebs cycle in conjugation in Escherichia coli K-12.

SUMMARY: Zygote formation between strains of Escherichia coli K-12 is dependent on a supply of free energy made available by the oxidation of carbohydrate via the Krebs cycle reactions. The simultaneous addition of glucose and a dicarboxylic acid of the tricarboxylic acid cycle, or an immediate precursor, to mating cells markedly stimulates the number of zygotes formed. Reagents known to inhibit reactions of the Krebs cycle inhibit zygote formation. Evidence was obtained that synthesis of protein or either pentose or deoxypentose nucleic acid was not necessary for zygote formation.

On the Stability of Deoxypentose Nucleic Acid Molecule DuringPurification.

On the Stability of Deoxypentose Nucleic Acid Molecule DuringPurification.

Nucleic Acid Changes in Rat Spleen after Localized X-Irradiation

In the previously reported investigation (1) the effect of whole-body X-radiation on the content and composition of rat tissue nucleic acids was described. When these experiments were undertaken, the possibility was considered that localized irradiation to the spleen might not produce the same effect as total-body exposure, since it has been demonstrated by a number of investigators (2-6) that lead shielding of various parts of the body affords protection against the effects of X-radiation. Histologic alterations in the spleen after localized X-radiation to this organ are considerably less severe than after an equivalent dose to the whole body (7). A parallel study was therefore begun in order to be able to compare the effect of localized irradiation to the spleen and whole-body exposure on the content and composition of rat spleen ribonucleic acid (RNA) and deoxypentosenucleic acid (DNA). While this work was in progress a report appeared by Petersen et al. (7) wherein it was found that the effect on rat spleen adenosinetriphosphatase (ATPase), 5-nucleotidase, and DNA content was considerably smaller after 800 r localized X-radiation to the spleen than after exposure of the whole body to the same dose of X-rays. The present report is concerned with the histological appearance, weight, nucleic acid content, and nucleic acid composition of rat spleen after 400 r X-radiation to the spleen only. Comparison is made with data on the spleen from the previous study (1); the changes observed were considerably smaller than after whole-body irradiation with the same dose of X-rays.

Changes in the amount of nucleic acids and free nucleotides during early embryonic development of sea urchins.

DURING the early embryonic period, the embryo of the sea urchin1,2, and also those of the frog3 and the chicken4, live upon deoxypentose nucleic acid, stored within the cytoplasm of the embryo; this reserve is used for the nuclei as they increase in number. Only after a certain period of development does the embryo start synthesizing deoxypentose nucleic acid itself. The time of appearance of this new synthesis is naturally different in animals belonging to different orders; but even within the same group of animals, closely related species start this synthesis at varied developmental stages. We have found this to be true for some species of sea urchins, Paracentrotus lividus from Roscoff, France, Psammechinus miliaris from Roscoff and from Kristineberg, Sweden, and Echinus esculentus from Kristineberg. The embryos of Paracentrotus and Psammechinus were reared at + 18° C. and those of Echinus at + 12° C. When cultivated at 12° C., Paracentrotus and Psammechinus showed almost the same rate of development as Echinus.

Nucleic Acid Changes in the Rat after Total-Body X-Irradiation

Among the observations made by the early investigators who studied cellular changes after X-irradiation was the effect on the chromosomes of the nucleus (1). These chromosome aberrations were subsequently related to the genetic mutations which frequently result from exposure to ionizing radiations. The more recently developed ideas of the close relationship and possible identity of deoxypentosenucleic acid (DNA) and genetic structure (2-6) and the general interest in the possible relation of ribonucleic acid (RNA) and DNA have stimulated investigations into the effect of radiation on the synthesis and breakdown of nucleic acids in a wide variety of organisms. A great deal of this work has been concerned with changes in the incorporation into RNA and DNA of isotopic tracers such as p32 and C14 in the form of simple nucleic acid precursors. Although some of this work is controversial, there is considerable agreement that subsequent to whole-body irradiation there is reduction in the synthesis of DNA, first demonstrated by Hevesy and co-workers (7) and later confirmed by many others (8-13). This is true even in mammalian liver (9), which is generally regarded as being radioresistant, at least with respect to histological alterations (14). Pelc and Howard (15) have recently suggested that the observed inhibition of DNA synthesis can be explained to a large extent on the basis of the arrest of mitosis in those cells which at the time of irradiation are in early interphase. One facet which has been largely overlooked in favor of isotope incorporation is the possibility of changes in the composition, and therefore possibly the structure, of the nucleic acids. With this in mind an investigation was undertaken to study the effect in vivo of X-rays on the composition of rat tissue nucleic acids. Shortly after this work was begun, a report appeared by Paigen and Kaufman (16), who studied