scholarly journals Nucleic acid metabolism in the ruminant

1971 ◽  
Vol 25 (1) ◽  
pp. 181-190 ◽  
Author(s):  
R. H. Smith ◽  
A. B. Mcallan
Keyword(s):  
Small Intestine ◽  
Polyethylene Glycol ◽  
Nucleic Acid ◽  
Acid Metabolism ◽  
Rumen Fluid ◽  
Nucleic Acid Metabolism ◽  
Total N ◽  
The Mean ◽  
Rna And Dna ◽  
Constant Percentage

1. Concentrations of nucleic acid nitrogen and other nitrogenous constituents were estimated in digesta taken from the proximal duodenum of calves which were given, either, one of a number of stall diets or pasture. These concentrations were compared, using polyethylene glycol (PEG) as a non-absorbed marker, with corresponding concentrations in rumen fluid and ileal contents.2. There was little net change in amounts of RNA or DNA between rumen and duodenum relative to PEG, but there was a marked increase in amounts of total-N. In duodenal digesta, for any one animal given most diets, nucleic acid-N formed a fairly constant percentage (8–11 for different animals) of the total non-ammonia-N. This value was lower (by about 3) than the corresponding percentage in rumen fluid. Comparison of nucleic acid-N: total-N ratios in duodenal contents and bacteria suggested that, for these diets, about 40–55% of the non-ammonia-N in duodenal contents was of microbial origin.3. During passage of digesta between the duodenum and ileum the mean percentage disappearances of total-N, RNA and DNA were estimated to be about 67, 85 and 75 respectively. There was evidence that these values varied with the amounts of the constituents entering the duodenum.4. Ammonia was absorbed in the omasum-abomasum only when concentrations in rumen fluid were high (40 mM), but even moderate concentrations of ammonia entering the duodenum (3 mM) were efficiently absorbed (about 90%) in the small intestine.

THE EFFECT OF ADRENOCORTICOTROPHIN ON THE NUCLEIC ACID METABOLISM OF THE RAT ADRENAL GLAND

1965 ◽  
Vol 32 (3) ◽  
pp. 303-312 ◽  
Author(s):  
R. C. IMRIE ◽  
T. R. RAMAIAH ◽  
F. ANTONI ◽  
W. C. HUTCHISON
Keyword(s):  
Nucleic Acid ◽  
Adrenal Gland ◽  
Dna Content ◽  
Adrenal Glands ◽  
Acid Metabolism ◽  
Female Rats ◽  
Nucleic Acid Metabolism ◽  
Prolonged Administration ◽  
Total Rna ◽  
Rna And Dna

SUMMARY Treatment of female rats with adrenocorticotrophin (ACTH) increased the RNA content of the adrenal glands progressively during a period of 3 days, the DNA content increased only after prolonged administration. By contrast, ACTH caused a decrease in the uptake of [32P]orthophosphate into the total RNA of the gland and into most of the RNA fractions of the subcellular components. A method of analysis for RNA and DNA based on the Schmidt-Thannhauser procedure has been evolved which eliminates extraction of nucleic acid by lipid solvents.

scholarly journals The degradation of nucleic acids in, and the removal of breakdown products from the small intestines of steers

1980 ◽  
Vol 44 (1) ◽  
pp. 99-112 ◽  
Author(s):  
A. B. McAllan
Keyword(s):  
Uric Acid ◽  
Small Intestine ◽  
Polyethylene Glycol ◽  
Nucleic Acid ◽  
Nucleic Acids ◽  
Terminal Ileum ◽  
Pyrimidine Nucleosides ◽  
Small Intestines ◽  
Rna And Dna ◽  
Serum And Urine

1. Nucleic acids and breakdown products were estimated in digesta taken from different sites in the small intestines of slaughtered steers given different diets. Amounts passing different sites were compared using cellulose as a non-digestible marker. The validity of this marker was checked with chromic oxide in some experiments. In other experiments, nucleic acids or derivatives were infused into the proximal duodenum of steers receiving diets of approximately equal proportions of flaked maize and hay. The amounts disappearing during passage through the small intestine were estimated using polyethylene glycol (PEG) as a non- absorbable marker.2. In the slaughter experiments the amounts of nucleic acids entering the small intestine varied with the type of diet. RNA and DNA disappeared on average, to extents of 89% and 80% respectively between the abomasum and the terminal ileum, irrespective of the diet. RNA disappearance occurred almost entirely in the proximal quarter of the small intestine, whereas that of DNA extended further along the tract.3. Nucleic acid degradation in the upper small intestine was accompanied by the transient appearance of adenosine, guanosine and pyrimidine nucleosides. These products were in greatest concentration in digesta from the first quarter of the small intestine and had generally completely disappeared by the terminal ileum.4. Of the different substances infused into the small intestine, free nucleic acids were removed to extents greater than 97%, adenine, guanine and uracil had completely disappeared, thymine and xanthine to approximately 80% and 95% and hypoxanthine and cytosine to only 51% and 48% respectively. The nucleosides adenosine and cytidine were also completely removed in the small intestine but were replaced, in part, by the catabolic products inosine plus hypoxanthine or cytosine respectively. Other nucleosides were removed to approximately half the extent of the corresponding bases.5. Serum and urine allantoin and uric acid levels were related to the amounts of purines entering the small intestines in free or bound form.

scholarly journals GROWTH CHARACTERISTICS OF POLIOVIRUS IN HELA CELLS: NUCLEIC ACID METABOLISM

1957 ◽  
Vol 106 (5) ◽  
pp. 641-648 ◽  
Author(s):  
H. F. Maassab ◽  
Philip C. Loh ◽  
W. Wilbur Ackermann
Keyword(s):  
Nucleic Acid ◽  
Hela Cell ◽  
Hela Cells ◽  
Acid Metabolism ◽  
Growth Characteristics ◽  
Nucleic Acid Metabolism ◽  
Cytoplasmic Component ◽  
Dna Contents ◽  
Infectious Cycle ◽  
Rna And Dna

The RNA and DNA contents of the nucleus and cytoplasm of the HeLa cell were determined. The rates of incorporation of P32 into the various nucleic acid fractions were established for the ordinary HeLa cell maintained under a set of standard conditions. The changes in the rates of incorporation of P32 and in the amounts of RNA and DNA which occurred subsequent to infection with poliovirus were followed throughout the infectious cycle. These changes were correlated with the intracellular appearance of the newly formed virus. A net synthesis of RNA occurred in the cytoplasmic component of the cell. The increase was detectable 2 hours before the first appearance of demonstrable virus and reached a maximum (2.5 times normal) at 6 hours. Viral increase was not maximal before the 7th hour after infection.

scholarly journals Nucleic acid metabolism in the ruminant

1970 ◽  
Vol 24 (2) ◽  
pp. 545-556 ◽  
Author(s):  
R. H. Smith ◽  
A. B. Mcallan
Keyword(s):  
Nucleic Acid ◽  
Microbial Population ◽  
Acid Metabolism ◽  
Rumen Fluid ◽  
Ammonia Nitrogen ◽  
Nucleic Acid Metabolism ◽  
Microbial Origin ◽  
Microbial Nitrogen ◽  
Nitrogen Contents ◽  
Cyclic Fluctuation

1. Concentrations of nucleic acid nitrogen (NA-N) and other nitrogenous constituents were estimated in samples of rumen fluid taken from calves and cows which were either given stall diets of varying nitrogen content or were allowed to graze pasture. Concentrations of NA-N ranged from 1.5 to 27.5 mg/100 g water.2. Ratios of RNA: DNA in rumen fluid were similar to those in rumen bacteria and were not related to those in the diets. Pure nucleic acids added to the rumen were rapidly degraded. It was therefore concluded that NA-N in rumen fluid was largely of microbial origin and provided an index of total microbial nitrogen.3. In most experiments, with an individual animal consuming diets of various nitrogen contents, NA-N formed a fairly constant percentage (8-15 for different animals) of the total non-ammonia nitrogen in rumen fluid. This suggested that nitrogen entering the rumen fluid limited microbial growth. Consumption of a diet containing extracted decorticated groundnut meal (diet B), however, led to lower values for this percentage than did the other diets. Diet B was also exceptional in leading to marked diurnal variations in NA-N concentrations in rumen fluid, suggesting a cyclic fluctuation in the size of the microbial population.4. Comparison of NA-N:total nitrogen ratios in rumen fluid and bacteria suggested that, for all the diets except diet B, 55–80 and 40–50% of the non-ammonia nitrogen in rumen fluid was of microbial origin for the calves and cows respectively.

scholarly journals Nucleic acid metabolism in the ruminant

1969 ◽  
Vol 23 (3) ◽  
pp. 671-682 ◽  
Author(s):  
A. B. Mcallan ◽  
R. H. Smith
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Acid Solution ◽  
Perchloric Acid ◽  
Trichloroacetic Acid ◽  
Acid Metabolism ◽  
Nucleic Acid Metabolism ◽  
Trichloroacetic Acid Solution ◽  
Rna And Dna

1. Procedures, based on those of Schmidt & Thannhauser (1945) and Schneider (1945), for the extraction and estimation of nucleic acids in bovine digesta were examined in detail.2. Final methods which were suitable for routine determination of RNA and DNA were essentially as follows. Digesta samples were extracted in the cold, first with a solution of trichloroacetic acid in ethanol, then with aqueous trichloroacetic acid solution and finally with lipid solvents. The dried residue was hydrolysed with alkali, purified by passage through a Dowex resin, and the RNA, in the form of mononucleotides, determined by U.V. absorption. DNA was determined separately in hot perchloric acid extracts of the original dried residue by colorimetric estimation of the deoxyribose content.

Picloram Sensitivity and Nucleic Acids in Plants

Weed Science ◽  
1970 ◽  
Vol 18 (1) ◽  
pp. 1-4 ◽  
Author(s):  
S. S. Malhotra ◽  
J. B. Hanson
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Herbicide Resistance ◽  
Dna Content ◽  
Acid Metabolism ◽  
Nucleic Acid Metabolism ◽  
Sensitive Species ◽  
Total Rna ◽  
Resistant Species ◽  
Rna And Dna

The changes in the nucleic acid metabolism were studied in plants susceptible and resistant to 4-amino-3,5,6-trichloropicolinic acid (picloram). The total RNA and DNA content of the tissue correlated inversely with the herbicide resistance; the resistant plants were low in nucleic acids, whereas sensitive plants were high. The increase in the nucleic acids of the sensitive species 24 hr after picloram treatment appeared to be associated with lower levels of ribonuclease and deoxyribonuclease. The inability of the resistant species to make more RNA may be associated with high levels of nucleases in the tissue.

EFFECT OF PROLACTIN ON NUCLEIC ACID METABOLISM DURING LACTOGENESIS IN THE RABBIT

1971 ◽  
Vol 51 (2) ◽  
pp. 265-270 ◽  
Author(s):  
A. A. SIMPSON ◽  
G. H. SCHMIDT
Keyword(s):  
Nucleic Acid ◽  
Dna Synthesis ◽  
Ribosomal Rna ◽  
Rna Synthesis ◽  
Acid Metabolism ◽  
Nucleic Acid Metabolism ◽  
Specific Effects ◽  
Intraductal Injection ◽  
Rna And Dna Synthesis ◽  
Rna And Dna

SUMMARY Lactogenesis was initiated by intraductal injection of prolactin into individual lobes of rabbit mammary glands previously developed by injections of oestrogen and progesterone. Nucleic acid metabolism was assessed at various times after prolactin treatment. A systemic pulse of [3H]thymidine or [3H]uridine was used to determine the specific effects of prolactin treatment on RNA and DNA synthesis and metabolism. Prolactin increased the rate of RNA synthesis. It is suggested that prolactin enhanced both the rate of RNA movement from the nucleus, and its rate of metabolism in the cytoplasm. The greatest increase in the rate of synthesis occurred in non-ribosomal RNA. Subsequent to its effect on RNA, prolactin enhanced DNA synthesis. Total RNA per cell increased as indicated by an increased RNA:DNA ratio. These changes are considered to be specifically due to the local action of prolactin.

EFFECT OF L-CYSTEINE ON α-AMYLASE PRODUCTION AND NUCLEIC ACID METABOLISM IN BACILLUS SUBTILIS

1963 ◽  
Vol 9 (3) ◽  
pp. 337-341 ◽  
Author(s):  
MICHIO OISHI ◽  
SHIGERU KITAYAMA ◽  
HAJIME TAKAHASHI ◽  
BUNJI MARUO
Keyword(s):  
Bacillus Subtilis ◽  
Nucleic Acid ◽  
Acid Metabolism ◽  
Nucleic Acid Metabolism ◽  
Amylase Production
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