bluuebunny/crossref_metadata_2025 huggingface dataset:
THE INFLUENCE OF APPARENT DIGESTIBLE ENERGY AND APPARENT DIGESTIBLE NITROGEN IN THE DIET ON WEIGHT GAIN, FEED CONSUMPTION, AND NITROGEN RETENTION OF GROWING MINK
Authors: Sinclair D. G. , Evans E. V. , Sibbald I. R.
Published: December 2009

The influences of the apparent digestible energy (A.D.E.) and the apparent digestible nitrogen (A.D.N.) content of the diet on the food consumption, nitrogen retention, and growth of mink from weaning to pelting age have been determined. It was demonstrated with diets containing from 3.33 to 4.21 Cal of A.D.E. and 26.14 to 39.76 mg of A.D.N. per g of dry matter that increasing the available energy and nitrogen in the diet had a beneficial influence on the growth of mink from 6 to 26 weeks of age. A linear relationship existed between the weight of food consumed and the reciprocal of the A.D.E. content of the food, which indicated that food consumption was largely regulated by the digestible energy content of the diet. The percentage of digestible nitrogen retained was curvilinearly related to the A.D.E.:A.D.N. ratio and appeared to be maximal when the diet contained 140 Cal of digestible energy per g of digestible nitrogen.
HYPOCHOLESTEROLEMIC AGENTS DERIVED FROM STEROLS OF MARINE ALGAE
Authors: Reiner E. , Topliff J. , Wood J. D.
Published: December 2009

Sterols isolated from two species of marine brown algae, Fucus gardneri and Sargassum muticum, were fed to young Leghorn cockerels. Both sterols caused a significant diminution in plasma cholesterol level.
THE MECHANISM OF THE RESERPINE-INDUCED ANTIDIURESIS IN THE RAT
Authors: Chaudhury R. R. , Chaudhury M. Roy , Lu F. C.
Published: December 2009

The delay of diuresis caused by reserpine in hydrated rats was not consistently prevented by prior administration of dibenamine or a potent anti-5-hydroxytryptamine substance (Methysergide), to the rats at the time of hydration. Carotid blood from rats under ethanol anaesthesia did not contain detectable antidiuretic activity. After administration of an intravenous dose of reserpine (50 μg/100 g) carotid blood collected at the time of maximum antidiuresis contained a detectable amount of antidiuretic activity which, in four experiments out of five, was destroyed by sodium thioglycollate. This, together with the finding that reserpine prolongs the time to the maximum rate of excretion of urine in hydrated rats, suggests that reserpine releases antidiuretic hormone from the neurohypophysis.
DIFFERENTIAL ABSORPTION OF PLANT STEROLS IN THE DOG
Authors: Kuksis A. , Huang T. C.
Published: December 2009

Eight adult female dogs (8 to 10 kg) with thoracic duct fistula were fed 5 to 10% solutions of mixed plant sterols in oleic acid, corn oil, or butter. The lymph, which flowed at a rate of 20 to 50 ml per hour, was drained for 18 to 26 hours. Each 2-hour collection was analyzed separately for cholesterol and plant sterols. Under comparable conditions and following a single meal containing plant sterol, about 35 mg of this sterol was transferred to lymph in 24 hours when corn oil was fed and 130 mg in the case of butterfat. At the time of maximum sterol absorption (8 to 12 hours after feeding) as much as 15% of the total lymph sterol was contributed by the plant sterols. Significant absorption of both β- and γ-sitosterol was observed, the γ-isomer being assimilated some 4 to 5 times as readily as the β-isomer. About 50% of the total lymph cholesterol was esterified. Essentially all of the absorbed plant sterol was free.
AMINO ACID TRANSPORT IN BRAIN CORTEX SLICES: I. THE RELATION BETWEEN ENERGY PRODUCTION AND THE GLUCOSE-DEPENDENT TRANSPORT OF GLYCINE
Authors: Abadom P. N. , Scholefield P. G.
Published: December 2009

Incubation of rat brain cortex slices with glycine in the presence of glucose leads to an accumulation of glycine in the slice. The extent of the accumulation is proportional to the level of adenosine triphosphate in the slice under a wide variety of experimental conditions which lead to changes in this level. Such conditions include change in the glucose concentration in the incubation medium, the presence of metabolic inhibitors, addition of uncoupling agents, alteration of the ionic composition of the medium, incubation under anaerobic conditions, addition of glutamate, X-irradiation, the use of rats of various ages, and the presence of adenosine in the incubation medium. The proportionality is apparent from the constancy of a factor, termed the transport quotient, which is obtained by dividing the extent of uptake of glycine by the observed level of nucleotide pyrophosphate present in the slices.
INHIBITION DE LA PHOSPHATASE ALCALINE INTESTINALE
Authors: Lazdunski Michel , Ouellet Ludovic
Published: December 2009

not available
SITES OF VAGAL ACTION IN ADRENALINE-INDUCED CARDIAC ARRHYTHMIAS
Authors: Dresel Peter E.
Published: December 2009

Intact vagus nerves are necessary for consistent induction of ventricular arrhythmia by adrenaline in barbiturate-anesthetized dogs although sinus bradycardia does not necessarily precede ventricular pacemaker activity. We have found that the threshold dose of adrenaline is not affected by maintaining the atrial rate electrically. In driven hearts, arrhythmia is preceded by partial or complete atrioventricular (AV) nodal block. AV nodal block is also observed without emergence of the ventricular pacemaker. AV nodal block during "nodal rhythm" induced by adrenaline in normal hearts has been demonstrated. It is concluded that although ventricular slowing always precedes ventricular arrhythmia in these preparations, the action of the vagi on nodal conduction is sufficient to allow emergence of the ventricular pacemaker both in the presence and the absence of maintained atrial rates.
THE TOXICITY OF BENZYLPENICILLIN IN ANIMALS ON VITAMIN A DEFICIENT TEST DIET, U.S.P. XIV
Authors: Boyd Eldon M. , Mulrooney Dorothy A. , Sargeant Everett J.
Published: December 2009

Young, adult albino mice and rats became more susceptible to the acute and chronic toxic effects of benzylpenicillin after they had been fed vitamin A deficient test diet, U.S.P. XIV, for about 1 month. At and after this interval, there occurred a significant increase in the percentage mortality from a single oral or subcutaneous LD50of benzylpenicillin in mice and the chronic toxicity of a daily oral 0.1 L-LD50of benzylpenicillin was augmented in rats. Replacement of vitamin A, in the deficient diet or by daily intramuscular injection, did not affect the increased susceptibility to benzylpenicillin toxicity. A dietary supplement containing nine other vitamins was also without effect. Change in diet alone was not a factor since rats did not become appreciably more susceptible to the toxic effects of a daily oral 0.1 L-LD50of benzylpenicillin when their diet was changed from a standard laboratory chow to a rachitogenic test diet. Some unknown factor or factors in vitamin A deficient test diet, U.S.P. XIV, therefore, made the animals more susceptible to the toxic effects of benzylpenicillin.
AN INCREASED RATE OF CHOLESTEROL BIOSYNTHESIS WITH MICROSOME FRACTIONS OF LIVER FROM KETOTIC GUINEA PIGS
Authors: Sauer F.
Published: December 2009

Cholesterol synthesis was studied in liver fractions obtained by differential centrifugation from young, adult, and ketotic guinea pigs. Both 10,000 × g and 105,000 × g sediment was required for maximum activity. Incubations were carried out in the presence of appropriate liver fractions from young guinea pigs in order to overcome the low rates of cholesterol synthesis in liver homogenates from adult guinea pigs. Microsome fractions from ketotic hyperlipemic guinea pigs actively promoted sterol synthesis when incubated with mitochondria plus supernatant from young guinea pigs, while microsome fractions from adult controls (fed or starved) decreased the rate of sterol synthesis in the same incubation system. The results of this investigation indicate that microsomes from hyperlipemic ketotic guinea pigs do not have a block in cholesterol synthesis characteristic of microsomes from starved animals, and that this microsome fraction has increased activity of HMG-CoA2reductase, one of the key enzymes of cholesterol synthesis.
THE ISOLATION AND IDENTIFICATION OF BOUND COUMARIN FROM MELILOTUS ALBA
Authors: Stoker J. R. , Bellis D. M.
Published: December 2009

A method is described for the isolation and purification of bound coumarin from seeds of Melilotus alba. Synthetic coumarinic acid β-glucoside has been prepared and its properties compared with those of bound coumarin. The results of these experiments confirm that bound coumarin and coumarinic acid β-glucoside are identical.
PURIFICATION OF THE GAMMA GLOBULIN CHARACTERISTIC OF CEREBROSPINAL FLUID
Authors: MacPherson Catherine F. C.
Published: December 2009

Experiments are described which have led to the standardization of a procedure for the purification of the γcglobulin characteristic of cerebrospinal fluid (CSF). The procedure involves the stepwise elution of three chromatographic fractions from a DEAE column by TRIS–HCl buffers at pH 8.5. The composition of the fractions will vary with the relative concentration of the γcglobulin in the CSF applied to the column. From an average CSF pool the first fraction, F1, eluted by 0.002 M TRIS–HCl will usually contain only the γcglobulin. The second fraction F2, eluted by 0.02 M TRIS-HCl, will contain a mixture of the γc, γs, and βcglobulins. The third fraction F3, eluted by 0.08 M TRIS–HCl, will contain chiefly γsglobulin as well as traces of the γcand βcglobulins. Most of the γcglobulin from pooled CSF may then be obtained in purified form by rechromatographing the F2's from several runs. Almost all of the γcglobulin applied will be found in F1. The γsand βcglobulins will be eluted in the other two fractions.
THE METABOLISM OF VALERATE-2-C14BY UREDOSPORES OF WHEAT STEM RUST
Authors: Reisener H. , Finlayson A. J. , McConnell W. B.
Published: December 2009

When uredospores of Puccinia graminis var. tritici race 15B were shaken in a medium containing M/30 phosphate buffer, pH 6.2, and valerate-2-C14, about 88% of the radioactivity was removed from the buffer solution in a period of 3 hours. About 40% of the carbon-14 taken from the buffer was found in a water-soluble extract of the spores and about 15% was respired as carbon dioxide. The result is compared with an earlier report that carbon 1 of valerate is more extensively released as carbon dioxide and less extensively incorporated into spore components. Glutamic acid, glutamine, γ-aminobutyric acid, and alanine of high specific activity were isolated. It was estimated from partial degradation that more than one-half of the carbon-14 of glutamic acid occurred in position 4 and that carbon 5 was very weakly labelled. Citric acid was also of high specific activity and was labelled predominantly in the internal carbons.It is concluded that respiring rust spores utilize externally supplied valerate by β-oxidation, which releases carbons 1 and 2 in a form which is metabolized as acetate by the tricarboxylic acid cycle.
VARIATIONS IN RATE OF HUMAN OSTEON FORMATION
Authors: Sedlin Elias D. , Frost Harold M.
Published: December 2009

The authors' method depends on labelling in vivo the zone of demarcation of actively forming osteons by tetracycline antibiotics. The drugs, thus deposited in bone, are visualized by fluorescence microscopy. The label is a circular or elliptical ring whose diameter indicates the degree of completeness of the osteon at the time of drug administration. A histogram of the ring diameters therefore classifies labelled osteons as regards stage of completion at the time of drug administration. If an average formation time is assigned to osteons measured, conclusions relative to the rate of formation of the average osteon can be derived.In a histogram plotted from more than 900 labelled osteons in bones of three patients, most of the labels were concentrated in the inner half of the osteon. The authors conclude that osteon formation is initially rapid both in terms of cubic microns of bone formed in a unit time and in terms of decrease in diameter of the Haversian canal; it decreases with passage of time, and it ends with a critical minimum diameter of the Haversian canal. A 2-week cyclic variation in rate may be superimposed on the overall plot.
FATTY ACID COMPOSITION AND GLYCERIDE STRUCTURE IN RATS FED RAPESEED OIL OR CORN OIL
Authors: Craig B. M. , Youngs C. G. , Beare Joyce L. , Campbell J. A.
Published: December 2009

The fatty acid compositions of liver, skin, abdominal fat, and residual degutted carcass from each of five rats fed diets containing corn or rapeseed oil for 21 weeks were determined by gas-liquid chromatography. Statistical analysis of the results showed no significant variations among rats or among cutaneous, abdominal, and carcass fats. In these fat depots, the proportions of fatty acids resembled those of the diet except for palmitic, palmitoleic, oleic, and erucic acids. Glyceride compositions of the body fats were in agreement with those predicted by Vander Wal's distribution theory.
THE DURATION OF THE EFFECT OF ISOLOGOUS PITUITARY IMPLANTS ON THE ESTROUS CYCLES IN THE INTACT MOUSE
Authors: Hagen E. Odette , Rawlinson H. E.
Published: December 2009

Implantations of pituitary isografts into intact female mice cause marked irregularity and lengthening in estrous cycles. This phenomenon can be produced by a single implantation of two pituitaries. The effect is still apparent 10 to 12 months later. It can be produced although in reduced degree by implantations into animals a year old. The basic mechanism is considered to be a more sustained production of prolactin by the graft. The effects of such transplants are maintained for several months.
UTILIZATION OF LIPIDS BY FISH: I. FATTY ACID OXIDATION BY TISSUE SLICES FROM DARK AND WHITE MUSCLE OF RAINBOW TROUT (SALMO GAIRDNERII)
Authors: Bilinski E.
Published: December 2009

The ability of the muscular tissue of fish to oxidize fatty acids has been studied on rainbow trout (Salmo gairdnerii). The rate of oxidation of Na hexanoate-1-C14, K octanoate-1-C14, and K myristate-1-C14by tissue slices from the lateral dark muscle and from the dorsal white muscle was determined at 25 °C by measuring the formation of C14O2. This transformation can be demonstrated in both the white and dark muscle; however, quantitatively a very pronounced difference exists between the two tissues, the dark muscle being more active.
METABOLIC EFFECTS OF DIETARY PROTEIN LEVEL WITH CALORIC RESTRICTION IN COLD-EXPOSED RATS
Authors: Beaton John R. , Orme T. , Turner A. , Laufer J.
Published: December 2009

Male albino rats were fed isocaloric diets (5%, 20%, and 40% protein and 10% corn oil by weight) in restricted amounts (6 g/rat per day) at environmental temperatures of 22 °C and 2 °C. Measurements were made of urinary excretion of nitrogen, potassium, sodium, phosphorus, and creatinine, of blood levels of glucose, urea, amino nitrogen, packed cell volume, and serum total proteins and of body contents of protein, moisture, and total crude fatty acids. Metabolic effects of food restriction were readily apparent at 22 °C and the diet appeared to play a role in modifying some of these effects in approximate proportion to the dietary protein level. With superimposition of cold exposure, metabolic differences among groups were decreased in degree with some suggestive evidence of a beneficial effect of increased dietary protein level and of a deleterious effect of decreased dietary protein (high carbohydrate) under these conditions.
PREVIOUS DIETARY PROTEIN LEVEL AND SURVIVAL OF STARVING RATS IN THE COLD
Authors: Beaton John R. , Orme T. , Turner A. , Laufer J.
Published: December 2009

The effect of the level of dietary protein (5%, 20%, 40% casein by weight) fed for 7 days in an environmental temperature of 22 °C, upon the survival of rats subsequently starved in an environmental temperature of 2 °C was studied. In these experiments ad libitum feeding, isocaloric feeding, and restricted feeding techniques were used, and the effects of thyroidectomy and thyroid feeding were investigated. In all cases, animals provided with the 5% protein diet survived for shorter periods than did those fed the 20% protein diet. In intact rats, but not in thyroidectomized rats, survival time appeared to be inversely related to rate of body weight loss in starvation. Differences in duration of survival among dietary groups are not explicable on the basis of differences in body weight, body composition, or total food intake prior to starvation. The results of experiments using thyroidectomized rats and thyroid feeding suggest that the effect of dietary protein level upon survival in subsequent starvation in the cold are not mediated through the thyroid gland.
EFFECT OF LYSINE AND WETTING AGENTS ON ACTIVATED PLASMINOGEN SOLUTIONS
Authors: Richard Maurel N. , Sanders Benjamin E.
Published: December 2009

The inclusion of lysine or of lysine with Emulphor 620 or Pluronics F68 increases the stability of a solution of streptokinase-activated plasminogen. Lysine plus Emulphor 620 greatly speeds up the development of caseinolytic activity in a solution of Cohn fraction III-3. Proteolytic activity thus produced may, within 5 hours, equal that produced by streptokinase. Where lysine and Emulphor 620 are present in the reaction mixture between Cohn fraction III-3 and streptokinase, higher fibrinolytic values appear than are produced by the same quantity of reactants without Emulphor and lysine.
THE REDUCTION OF CYTOCHROMEcBY HYDROQUINONE
Authors: Williams G. R.
Published: December 2009

The kinetics of reduction of ferricytochrome c by hydroquinone have been studied. The reaction does not conform to a simple second-order rate equation and it is demonstrated that the deviations are brought about by the presence of p-quinone, one of the products of the reaction. The accelerating effect of p-quinone is explained tentatively on the basis of an involvement of the semi-quinone. The effects on the reaction of pH, ionic strength, and temperature are reported and used to suggest features of the reaction mechanism.
THE SEPARATION AND PURIFICATION OF VI AND O ANTIGENS OF S. TYPHI USING A COLUMN PRECIPITATION TECHNIQUE
Authors: Griffiths B. W. , Diena B. B. , Greenberg L.
Published: December 2009

Vi and O antigen fractions have been obtained in purified as well as separated forms from a crude extract of Salmonella typhi Ty-2 strain. The method applied the use of alcohol fractionation as well as salt fractionation of the material on an inorganic column bed. Alcohol fractionation alone neither separated nor purified the antigens significantly. When cetyl pyridinium chloride (CPC) was maintained in constant concentration in the elution solvents, the Vi and O serologically active materials could not be eluted by the usual alcohol–water solvents, but could be removed in separated and purified forms by salt solvents (MgCl2). The essential requirement of CPC in the fractionation is discussed.
CONVERSION OF METHIONINE AND THREONINE TO FATTY ACIDS BY ADIPOSE TISSUE
Authors: Feller D. D. , Feist E.
Published: December 2009

Epididymal adipose tissue was incubated with uniformly labelled (14C)-methionine, (2-14C)-methionine, and uniformly labelled (14C)-threonine. Each of these compounds is actively metabolized by adipose tissue, as evidenced by the generation of14CO2and (14C)-fatty acid. Evidence was gathered in regard to the intermediary pathways by which these amino acids are utilized by adipose tissue and the general conclusion is drawn that these pathways are similar to those postulated for other tissues. These experiments further emphasize the central role that propionate plays in adipose tissue lipogenesis.
EVALUATION OF PROTEIN IN FOODS VIII. INFLUENCE OF QUALITY AND QUANTITY OF DIETARY PROTEIN ON NET PROTEIN UTILIZATION
Authors: Morrison A. B. , Sabry Z. I. , Gridgeman N. T. , Campbell J. A.
Published: December 2009

The relation between the percentage of dietary Calories derived from protein (P) and the corresponding net protein utilization (N.P.U. or U) was studied with various proteins of different nutritional value. At P > 40 the experimental results (from rats) did not fit the Miller–Payne linear model. A semilogarithmic plot, however, accommodated all the data, ranging from P = 10 to P = 80. The new model yields, by extrapolation, values of maximum utilization that agree well with the protein (chemical) scores. A general prediction equation is given that enables N.P.U. to be calculated from a knowledge of P and of the chemical score of the protein or protein mixture at issue.
SIDEROCALGIPHYLACTIC SENSITIZATION TO MASTOCYTE DISCHARGERS
Authors: Selye Hans , Dieudonné Jean-Marie , Veilleux René
Published: December 2009

Experiments on rats indicate that, following so-called siderocalciphylactic sensitization with dihydrotachysterol (DHT) and ferric dextran (Fe-Dex), the subcutaneous injection of minute amounts of various mastocyte depleters produces local calcified skin wheals. The possible role of the mastocyte in the production of physiologic and pathologic calcium depositions is briefly discussed.
METABOLISM OF 6-PHOSPHOGLUCONIC ACID AND GLUCONIC ACID IN SALMO GAIRDNERII
Authors: Tarr H. L. A.
Published: December 2009

C14O2is formed 50 to 75 times as fast in Salmo gairdnerii (steelhead salmon) when UC14glucose is injected intraperitoneally or intramuscularly as when 6PG is similarly administered. The rate of C14O2formation is the same when fish are injected with C1C14-, C6C14-, or UC14-6PG. Intramuscular or intravenous injection of C6C14-6PG, UC14-6PG, or UC14-GA results in C14labelling of "dextrin", maltose, glucose, G6P, F6P, FDP, and GA. On the contrary, maltose, glucose, and the hexosephosphates remain either non-radioactive, or have extremely low SA, when fish are injected with C1C14-6PG. These facts are consistent with slow metabolism of 6PG via the HMP pathway in living fish. Since GA of fairly high SA is found in fishes injected with C14-6PGand radioactive hexosephosphates are found in fish injected with C14-GA, it is concluded that live fish can liberate orthophosphate from 6PG and phosphorylate GA. It is indicated that, at least until the rate of C14O2formation from radioactive 6PG has been studied with tissues known to utilize either the HMP or the EMP pathways in glucose metabolism, no quantitative interpretation can be placed on use of such compounds in attempts to assess the comparative contributions of these two pathways in carbohydrate metabolism.
FORMATION OF PHOSPHATIDES FROM C14-LABELLED PRECURSORS IN RAT BRAIN SLICES. EFFECT OF CHLORPROMAZINE
Authors: Pritchard E. T. , Rossiter R. J.
Published: December 2009

The addition of chlorpromazine (0.1 mM) to slices of rat brain respiring in a suitable medium caused an increase in the incorporation of radioactivity from glycerol-1-C14, glycine-2-C14, and serine-3-C14 into the phospholipids of the slices. There was no increase in the incorporation of radioactivity from choline-1,2-C14 or ethanolamine-1,2-C14. Examination of the individual phosphatides showed an increase in the incorporation of radioactivity from glycerol-1-C14 into phosphatidc acid and phosphatidyl serine, with no change for lecithin and phosphatidyl ethanolamine. Higher concentrations of chlorpromazine (1.0 mM) either inhibited (glycerol-1-C14, choline-1,2-C14), did not significantly alter (glycine-2-C14, ethanolamine-1,2-C14), or stimulated (serine-3-C14) the incorporation of radioactivity into phospholipids. These results are discussed in relation to previous experiments, in which it was found that the addition of chlorpromazine (0.1 mM) to slices of guinea pig brain caused an increase in the incorporation of inorganic P32 into phosphatidic acid, phosphatidyl inositol, phosphatidyl serine, but not into lecithin or phosphatidyl ethanolamine.
THE ACTION OF CLOSTRIDIUM PERFRINGENS PHOSPHATIDASE ON THE LIPOVITELLINS AND OTHER EGG YOLK CONSTITUENTS
Authors: Burley R. W. , Kushner D. J.
Published: December 2009

A study was made of the action of phosphatidase D (phospholipase D) from Clostridium perfringens (C. welchii) on five constituents of the yolk of hens' eggs (α- and β-lipovitellin, the low-density lipoprotein fraction, granules, and lecithin) in aqueous solution, in the absence and presence of chloroform. Although the untreated lipovitellins were little affected by the enzyme, after absorption of chloroform, a large proportion of their phospholipids was hydrolyzed. In this respect they resembled lecithin but differed from the low-density yolk lipoproteins, whose phospholipids were rapidly hydrolyzed by the enzyme in the presence or absence of chloroform. The mechanism of this type of chloroform activation is discussed.
NADPH AND NADH OXIDATION BY GUINEA PIG POLYMORPHONUCLEAR LEUCOCYTES
Authors: Iyer G. Y. N. , Quastel J. H.
Published: December 2009

A homogenate of guinea pig polymorphonuclear leucocytes contains an enzyme system capable of oxidizing, in presence of oxygen, NADPH and NADH with the formation of hydrogen peroxide. The enzyme is much more active towards NADPH than to NADH. The presence of manganese ions strongly enhances the oxidase activity. It is suggested that the release of the NADPH oxidase in the leucocytes, during phagocytosis, accounts for the stimulation of the hexose monophosphate pathway that occurs in phagocytosis.
EFFECTS OF ACETYLSALICYLATE AND 2,4-DINITROPHENOL ON METABOLISM AND TRANSPORT IN RAT BRAIN CORTEX IN VITRO
Authors: Gonda O. , Quastel J. H.
Published: December 2009

The effects of acetylsalicylate and of 2,4-dinitrophenol on the metabolism and transport processes of rat brain cortex slices incubated at 37° in glucose–Ringer media under various conditions have been investigated. The following processes are suppressed by acetylsalicylate (5 mM) or dinitrophenol (0.05 mM) to a much greater extent in media containing 105 mM KCl or 10 mM NH4Cl (which stimulate brain respiration) than in normal media:(a) respiration;(b) incorporation of phosphate into ATP and ADP;(c) conversion of creatine to phosphocreatine;(d) uptake of glutamate or of creatine from the medium to the tissue.The two drugs increase the leakage of amino acids from rat brain cortex slices into the medium, the effects being greatest in the presence of 105 mM KCl or 5 mM glutamate or in the absence of glucose. They change the yields of labelled amino acids from labelled glucose or labelled glutamate.Labelled glutamate is converted to labelled aspartate, γ-aminobutyrate and glutamine in rat brain cortex slices, the addition of glucose bringing about increased yields of glutamine and γ-aminobutyrate and a decreased yield of aspartate. The formation of labelled glutamine from either labelled glutamate or from labelled glucose is suppressed by acetylsalicylate or dinitrophenol, the effects being greater in the presence of 105 mM KCl or 10 mM NH4Cl.The increased sensitivity of the stimulated tissue metabolism to the drugs, in the presence of high K+, or of NH4+or of glutamate, is probably explained by the fact that there is a fall, under these conditions, in the tissue phosphocreatine level. There is, therefore, less reserve phosphocreatine to maintain the level of ATP when neuronal oxidative phosphorylation is suppressed by the addition of acetylsalicylate or of dinitrophenol.
HYDROLYSIS OF CALF THYMUS DEOXYRIBONUCLEATE BY PANCREATIC DEOXYRIBONUCLEASE: I. A STUDY OF THE OLIGONUCLEOTIDES LIBERATED IN THE PRESENCE OF MAGNESIUM OR MANGANESE IONS
Authors: Hurst R. O. , Becking G. C.
Published: December 2009

The oligonucleotides obtained from deoxyribonucleic acid by the action of pancreatic deoxyribonuclease in the presence of magnesium ions or manganous ions have been analyzed by ion exchange chromatography and by determination of the relative amounts of purine and pyrimidine deoxynucleotides occupying the 5′-terminal position. Evidence of a difference in the specificity of action of the enzyme that is dependent upon the nature of the metal ion activator employed has been adduced.
EXPERIMENTS ON ATROPINE-RESISTANT VASODILATATION IN SALIVARY GLANDS
Authors: Strömblad B. C. R. , Dresel Peter E.
Published: December 2009

Vasodilatation induced by stimulation of the parasympathetic nerve supply to the submaxillary and the parotid glands has long been known to be resistant to the blocking effect of atropine. We have found that dichloroisoproterenol does not block this vasodilatation, that d-tubocurarine blocks it by interfering with ganglionic transmission, and that a hemicholinium, HC-3, blocks it gradually under conditions in which interference with ganglionic transmission is excluded. It is concluded that the mechanism of vasodilatation includes the action of cholinergic nerves.
THE EFFECT OF SUBLETHAL DOSES OF ARTIFICIAL SUNLIGHT ON ADAPTIVE ENZYME SYNTHESIS BY ESCHERICHIA COLI
Authors: Webb S. J.
Published: December 2009

The effect of sublethal doses of artificial sunlight and individual wavebands of light on the ability of Escherichia coli to synthesize the enzymes concerned in lactose oxidation have been studied. It was found that direct sunlight completely inhibited enzyme synthesis but did not affect the action of preformed enzymes. Blue and yellow light were both active in preventing enzyme synthesis but the blue region of the spectrum was by far the most effective. No effect of red light could be demonstrated. Staining cells with yellow or red dyes reduced the action of blue light whereas staining the cells with a blue dye increased the effectiveness of yellow light.
IDENTIFICATION OF CHLOROGENIC ACID IN CASTOR BEAN AND ORANGES
Authors: Siddiqi Azra I. , Freedman Samuel O.
Published: December 2009

Chlorogenic acid was identified as a constituent of castor bean pomace and of orange pulp by paper chromatography, by infrared and ultraviolet spectrophotometry, and by an immunological cross-neutralization technique. A new extraction and concentration procedure is described which facilitates the identification of small amounts of chlorogenic acid in plant materials. The significance of the results is discussed in relation to the known allergenic activity of chlorogenic acid.
THE EFFECTS OF SIALIDASE ON PSEUDOCHOLINESTERASE TYPES
Authors: Ecobichon D. J. , Kalow W.
Published: December 2009

Hereditary variants of human serum cholinesterase were exposed to the action of sialidase. The removal of the sialic acid residues had no effect on the kinetic properties of the esterases but greatly affected the electrophoretic mobility. In starch gel, there were no differences between the pseudocholinesterase types whether sialidase-treated or untreated. This observation permits two conclusions: first, the differences between the esterase types must reside in the protein cores, and second, the different variants must possess equal amounts of sialic acid per protein molecule. According to Liddell et al. there is a charge difference between esterase molecules of different type; since this cannot be accounted for by sialic acid content, the distinguishing characteristics are likely due to differences of amino acid composition.
CALCIUM ACCUMULATION AND RESPIRATORY ACTIVITY OF THE SMALL INTESTINE OF THE RAT
Authors: Charnock J. S.
Published: December 2009

The possible dependence of calcium accumulation upon respiratory activity of the rat small intestine has been investigated in vitro. The oxygen consumption of this tissue was relatively insensitive to the concentration of calcium in the medium; and the accumulation of radioactive calcium was greatly dependent upon ambient calcium concentration. At low concentrations of the medium the ratio of tissue calcium to that in the medium greatly exceeded unity, indicating an accumulation of this ion against a concentration gradient. However, this effect was also seen when the tissues were incubated in a gas phase of nitrogen instead of oxygen, demonstrating the lack of dependence of this process on tissue respiration. The rate at which calcium accumulated at 0° also suggests that the accumulation of calcium by the small intestine is not a metabolically controlled process but rather is a binding phenomenon similar to that reported for salivary gland of the rat.
SIGNIFICANCE OF N15EXCESS IN NITROGENOUS COMPOUNDS OF BIOLOGICAL ORIGIN
Authors: Gaebler O. H. , Choitz Harold C. , Vitti Trieste G. , Vukmirovich Robert
Published: December 2009

The purpose of this study was to determine whether the small increase in abundance of N15normally found in nitrogenous compounds of biological origin is primarily due to mass discrimination in nitrogen metabolism, or to reproducible analytical errors.This problem was approached by repeatedly determining N15in the same series of nine amino acids, either purchased in chromatographically pure form or isolated from proteins of rat liver, dog serum, and six plant sources. Proteins and amino acids included in the study were selected on the premise that concentration or redistribution of N15might occur in such processes in urea formation, nitrogen transfer, or nitrogen fixation. Data for N15excess in a series of alkaloids were also secured.Standard deviations obtained in series of analyses were too small, and values for N15excess in the same amino acids isolated from different sources too variable, to permit interpreting the observed N15excess as a reproducible error. Distribution of N15in amino acids of the animal proteins studied resembled that observed when N15-labelled amino acids or ammonium compounds are given. Differences between results for amino acids of animal and plant origin also supported the idea that the small excess of N15normally found is metabolically as well as statistically significant. Results for N15in amide nitrogen likewise supported this view. The smallest excess of N15occurred in amino acids from proteins of legumes, which fix nitrogen. In synthetic amino acids, the concentration of N15was more often below than above normal abundance.
INCORPORATION OF INORGANIC P32INTO PHOSPHOLIPIDS OF BRAIN SLICES: EFFECT OF CERTAIN TRANQUILLIZING DRUGS
Authors: Magee W. L. , Rossiter R. J.
Published: December 2009

Promazine, promethazine, tetrameprazine, and WY 1172, four tranquillizing drugs that are derivatives of phenothiazine, resembled chlorpromazine in that when they were added in a concentration of 0.1 mM to slices of guinea pig brain respiring in a suitable medium they stimulated the incorporation of inorganic P32into the phospholipids of the slices. With one of the drugs, promethazine, this concentration of 0.1 mM was found to cause no significant increase in respiration, in aerobic glycolysis, or in the concentration of phosphocreatine. In higher concentrations (1.0 mM), all of the compounds inhibited the labelling of phospholipid. Promethazine caused a reduction in respiration and in the concentration of phosphocreatine, accompanied by an increase in aerobic glycolysis. Methylene blue, a derivative of phenothiazine with no reported tranquillizing properties, did not stimulate the labelling of phospholipid in brain slices. Azacyclonol, pipradrol, and mepazine, drugs that are derivatives of piperidine, also stimulated phospholipid labelling in low concentrations and inhibited the labelling at higher concentrations. Piperidine and benzhydrol, the two components from which azacyclonol is derived, did not stimulate phospholipid labelling at the concentration which was most effective for azacyclonol. Low concentrations of benzhydrol, however, caused a slight stimulation. Meprobamate and phenaglycodol, two other compounds with reputed tranquillizing action, had either little or no effect. Most of the substances tested inhibited phospholipid labelling when they were added in sufficiently high concentrations.
URINE TITRATABLE ACIDITY AND AMMONIA EXCRETION DURING HYPOTHERMIA
Authors: Kanter G. S. , Lubinski R. H. , Shimandle D.
Published: December 2009

Hydrogen ion secretion by the kidneys of anesthetized hypothermic dogs was measured to ascertain if the hypothermic kidney helps to compensate for the acidosis which develops during exposure to cold. Artificial respiration was not used. Total hydrogen ion excretion was measured as the sum of total titratable acid and ammonia excreted. A constant saline infusion of 2 ml/min was employed to maintain a urine flow adequate for analysis procedures. Though anaerobic arterial pH, corrected to body temperature, fell significantly from 7.41 during control to 7.27 at 27 °C, urinary pH remained at control levels of approximately 6.8. Neither titratable acid nor ammonia excretion increased in response to the hypothermic acidosis as would have occurred during normothermia with a similar low pH. Total titratable acid excretion fell from a control value of 0.011 meq/min to 0.005 meq/min at 27 °C. Ammonia excretion, after a mild increase from a control value of 0.008 meq/min, fell to 0.006 meq/min at 27 °C. The failure of the hypothermic kidney to excrete additional hydrogen ions in the face of acidosis indicates that the renal acidification mechanism is temperature-dependent.
PENICILLAMINE AND VITAMIN B6INTERRELATIONSHIPS IN THE RAT
Authors: Heddle J. G. , McHenry E. W. , Beaton G. H.
Published: December 2009

DL-Penicillamine administered in the diet at the 0.25% level produced a marked lowering of food intake and body weight. Using blood transaminase activities as criteria, a definite antagonism to vitamin B6was demonstrated. The response of animals to the drug did not differ between sexes. Transaminase activity changes were apparent within 13 days of treatment. They were not the result of a reduced food intake. Administration of 800 μg of pyridoxine hydrochloride per 10 g of diet to animals receiving penicillamine approximated the maximal prevention of the effects of the drug upon food intake, body weight, and transaminase activity. The effects were not completely prevented by dosages of vitamin B6as high as 2000 μg per 10 g of diet. Attention is drawn to the possible significance of these studies in the treatment of patients (Wilson's disease) with penicillamine. On the basis of extrapolations from the present studies in rats, 50 mg of pyridoxine hydrochloride might be expected to give near-maximal protection against possible vitamin B6-antagonistic effects of 1.5 g of DL-penicillamine.
UNCOUPLING OF OXIDATIVE PHOSPHORYLATION BY IONIZING RADIATION: II. THE STABILITY OF MITOCHONDRIAL LIPIDS AND CYTOCHROMEc
Authors: Scaife J. F. , Hill B.
Published: December 2009

Mitochondria isolated from the thymus of rats or rabbits 4 hours after 800 rads of ionizing radiation show uncoupling of their oxidative phosphorylation. There are no significant differences in the contents of phospholipids, neutral lipids, or total fatty acids between normal and uncoupled mitochondria. There was no evidence of the formation of any lipid uncoupling factor in thymus mitochondria from irradiated animals.Heart or liver mitochondria isolated from animals irradiated up to 12 hours previously showed no uncoupling of oxidative phosphorylation although preparations in various media could be made with reduced cytochrome c contents. No effect of irradiation upon endogenous cytochrome c or its binding in these mitochondria could be detected.Thymus mitochondria would appear to contain very low quantities of cytochrome c (less than 0.2 μg per mg protein), yet still be tightly coupled. It is suggested that this low level may indicate a critical condition at which radiation damage could become manifest.
THE WHEAT LEAF PHOSPHATASES: VI. SOME PROPERTIES OF THE ENZYME SYSTEM HYDROLYZING ADENOSINE-5′-PHOSPHATE AND PHENOLPHTHALEIN DIPHOSPHATE IN CRUDE JUICE PREPARATIONS
Authors: Roberts D. W. A.
Published: December 2009

At least two enzymes are probably involved in the hydrolysis of mixtures of β-glycerophosphate, phenolphthalein diphosphate, and adenosine-5′-phosphate. One enzyme is primarily responsible for the hydrolysis of β-glycerophosphate whereas the other enzyme hydrolyzes adenosine-5′-phosphate and phenolphthalein diphosphate but has little activity on β-glycerophosphate.The liberation of orthophosphate from adenosine-5′-phosphate and phenolphthalein diphosphate by the enzyme in wheat leaf juice is inhibited by 0.005 M adenosine but not by 0.02 M phosphate. The inhibition of this enzyme by fluoride is markedly smaller than the inhibition of β-glycerophosphatase. The enzyme that hydrolyzes phenolphthalein diphosphate transfers phosphate from phenolphthalein diphosphate to adenosine to form adenosine-5′-phosphate.Experiments on the pH optimum for the enzymic hydrolysis of both adenosine-5′-phosphate and phenolphthalein diphosphate by undialyzed and dialyzed juice preparations with or without added Mg++suggest that there may be more than one enzyme with different pH optima acting on both adenosine-5′-phosphate and phenolphthalein diphosphate.
THE SINGLE BREATH DIFFUSING CAPACITY AND THE PERMEABILITY OF THE LUNGS OF NORMAL MAN
Authors: Rosenberg Edith
Published: December 2009

The single breath diffusing capacity for CO, DL, and the permeability of the lungs, K, were measured in six male and two female medical students at various lung volumes. The subjects rested 15 minutes before each test and the expired alveolar volume as well as breath-holding time and inspired volume were recorded on a spirogram. The test gas used consisted of 0.3% CO, 0.3% SF6, 20% O2, and the balance N2. The sample of alveolar gas expired after breath-holding was analyzed for CO and SF6 on a vapor fractometer using a 2-meter molecular sieve column. DL varied with the surface area of the subjects as well as with the alveolar volume at which the test was performed. K, on the other hand, was independent of the size of the subjects and decreased towards a constant value as lung volume became large. K should, therefore, be more reproducible than DL. The average permeability of the eight subjects used in this study was 0.0715 ml CO per second per ml of alveolar volume. In every experiment, alveolar volumes were also calculated from the SF6 dilution. These values, VD, were compared to alveolar volumes calculated from the maximum lung volumes, VA. For the males there was no measurable difference between alveolar volumes calculated by these two methods when 2 liters or more of test gas were inspired. It is suggested that the replacement of the measurement of DL in pulmonary function laboratories by an evaluation of K and VD may transform the single breath diffusing capacity test into a useful diagnostic tool.
STUDIES ON WHEAT PLANTS USING CARBON-14 COMPOUNDS: XIX. OBSERVATIONS ON THE METABOLISM OF LYSINE-C14
Authors: Nigam S. N. , McConnell W. B.
Published: December 2009

When generally labelled lysine-C14or α-aminoadipic acid-6-C14was administered to wheat seedlings 48% and 57%, respectively, of the carbon-14 was recovered in water-soluble materials. An additional 39% of the lysine carbon-14 was found in the insoluble residue whereas with α-aminoadipic acid-6-C14only 11% of the carbon-14 was in the residue. When lysine-C14was administered, lysine, pipecolic acid, and α-aminoadipic acid had high specific activities while glutamic acid and some related substances contained significant amounts of carbon-14. By contrast, when α-aminoadipic acid-6-C14was used as tracer the lysine and pipecolic acid isolated were weakly labelled, although α-aminoadipic acid of very high specific activity was recovered from the tissues. Appreciable carbon-14 was also found in the glutamic acid, 63% of this being in position-5.The data are taken as evidence that α-aminoadipic acid and pipecolic acid are on the pathway of lysine metabolism, with acetate being a product of further degradation. The results provide no evidence that α-aminoadipic acid can serve as a precursor to lysine.
SOME OBSERVATIONS ON THE INOTROPIC ACTION OF ATP ON THE HEART OF THE FROG
Authors: Ottolenghi Paul
Published: December 2009

The action of ATP on the tension developed during the contraction of frog ventricles can be separated into two distinct phases: a short-lived inotropic effect (response I), and a second, more prolonged inotropic action which develops after the first response has subsided (response II). The sites upon which ATP acts to produce response I become blocked to further action of ATP once the response has been elicited, and they have to be reactivated (e.g. by washing) for them to become available again. Response I may be elicited without response II, by using low concentrations of ATP. Response II may be obtained by itself by first blocking response I with a low concentration of ATP.ADP is as active as ATP, but AMP alone or together with pyrophosphate is ineffective. Results with ITP and IDP suggest that the 6-amino group of the adenine of ATP and ADP is necessary for response I to be elicited, but not for response II.
OBSERVATIONS ON THE FUNCTION OF A TRANSPLANTED KIDNEY
Authors: Dossetor J. B. , Morgen R. O. , Beck J. C.
Published: December 2009

Several aspects of the function of a transplanted kidney are recorded. The transplanted kidney functioned well during the first 24 hours after implantation. During this time osmotic diuresis occurred, with concomitant excretion of sodium and chloride, in the presence of an antidiuretic stimulus.There was a delayed decrease in function of the transplanted kidney, occurring during the second and third days after the operation, followed by subsequent gradual improvement.The return of azotemia during the fourth week after operation was due to a high dietary nitrogen intake and, probably, a continuing low rate of protein anabolism. The azotemia caused osmotic diuresis with increased urine volume, sodium and chloride excretion, and rapid loss of weight.It is believed that the secondary hyperparathyroidism of chronic uremia was detected by the renal handling of phosphate by the transplanted kidney.Data relating to the diurnal rhythm of electrolyte excretion are presented.
HYDROLYSIS OF CALF THYMUS DEOXYRIBONUCLEATE BY PANCREATIC DEOXYRIBONUCLEASE: II. ISOLATION AND ANALYSIS OF THE MONONUCLEOTIDES AND DINUCLEOTIDES OBTAINED BY ENZYMIC DEGRADATION IN THE PRESENCE OF MANGANOUS IONS
Authors: Becking G. C. , Hurst R. O.
Published: December 2009

Analysis of the oligonucleotides produced by the exhaustive hydrolysis of calf thymus DNA by pancreatic DNAase in the presence of manganous ions at pH 6.6 shows an increase in the concentration of mononucleotides and dinucleotides which are found to comprise 5% and 49% of the total nucleotide phosphorus. The relative amounts of the isomeric dinucleotides formed during manganous ion activation of the enzyme differ from those obtained for magnesium ion activation. The results are interpreted as indicating a random attack by the enzyme at multiple points in an endonuclease action with certain linkages being more susceptible than others. The evidence suggests that the pPu–pPu linkage is stable and that the increased liberation of purine nucleotides occupying the 5′-terminal phosphate position is due to hydrolysis of pPy–pPu linkages.
INHIBITION AND ACTIVATION OF ADENYLOSUCCINIC SYNTHETASE BY 8-AZAGUANOSINE TRIPHOSPHATE
Authors: Cohen L. H. , Parks Jr. R. E.
Published: December 2009

8-Azaguanosine triphosphate can function in place of GTP in the reaction catalyzed by adenylosuccinic synthetase. The Michaelis constant and maximal velocity for the reaction obtained with the analogue are lower than those obtained with GTP. As a result, 8-azaGTP increases the reaction rate at low GTP concentrations and inhibits competitively at high GTP concentrations. It is suggested that this type of inhibition might be exploited in the development of chemo-therapeutic analogues specific for tissues containing high concentrations of a coenzyme or metabolite.