Adenosine Mono Research Articles

Infrared Spectroscopic Studies of the Interaction between Polyuridylic Acid and Adenosine mono- and oligonucleotides

Infrared Spectroscopic Studies of the Interaction between Polyuridylic Acid and Adenosine mono- and oligonucleotides

Adenosine‐sensitive adenylate cyclase in rat striatal homogenates

There is a good deal of evidence suggesting that adenosine and its phosphorylated derivatives (adenosine mono-, diand triphosphate) might act in the brain like a neurohumoral substances. These compounds can be taken up into brain slices [ 1,2] or synaptosomal fractions [3] through a specific uptake system. Furthermore they are released by electrical field stimulation and K’ [2,4,5] such release being Ca” dependent [3]. Adenosine and its phosphorylated derivatives inhibit the firing of Purkinje [6] and olfactory cortex neurones [7]. Like other well-known neurotransmitters, adenosine derivatives induce the accumulation of adenosine 3’,5’-monophosphate (cyclic AMP) in brain slices [ 1,7,1 l] and neuronal cell lines in culture [ 12,151. Two mechanisms may be involved in this effect. Adenosine can be converted into ATP in a pool accessible to adenylate cyclase, but this is unlikely, since prevention of adenosine uptake by dipyridamole does not inhibit cyclic AMP accumulation induced by adenosine [ 121. In addition, 2 chloro-adenosine, which is not converted into AT?, increases cyclic AMP production [ 161. Adenosine (and possibly its phosphorylated derivatives) could increase cyclic AMP production by actin extra cellularly on a specific membrane receptor coupled with an adenylate cyclase. The present report confirms this last hypothesis since we were able to demonstrate the presence of an adenosine-sensitive adenylate cyclase in striatum homogenates.

Zirconium-hydroxide-mediated alkaline hydrolysis of phosphate esters

Under mildly alkaline conditions (pH 7–9) the hydrolysis of phosphate monoesters such as 4-nitrophenyl phosphate, glucose 1-phosphate, and glycerol 1-phosphate proceeds slowly, if at all. However, in the presence of gelatinous zirconium hydroxide the rate of hydrolysis of 4-nitrophenyl phosphate is increased by a factor of ca. 30, although the rates of hydrolysis of a range of phosphate esters and related compounds such as adenosine mono- and tri-phosphates, nitrophenyl glycosides, and nitrophenyl sulphates and acetates are not altered. The effects of pH, zirconium hydroxide concentration, phosphate ion, and zirconium phosphate upon this catalysis are described. Titanium(IV) hydroxide exhibited only a slight catalytic effect. A mechanism for the selective catalytic reaction of the zirconium hydroxide is suggested.

The inhibitory effect of adenosine and related nucleotides on the release of acetylcholine

Isolated Auerbach's plexus-longitudinal muscle preparations from guinea-pig ileum and slices of the rat cerebral cortex have been used to study the effect of adenine nucleotides on the release of acetylcholine. The release of acetylcholine evoked by cholecystokinin was completely inhibited by adenosine. The effect of nucleotides on neuro-effector transmission of electrically stimulated longitudinal muscle strip was also studied. Adenosine and adenosine triphosphate reduced the release of acetylcholine provided a low frequency of stimulation was applied. While the three adenine nucleotides (adenosine mono-, di- and triphosphate) dose-dependently reduced neuro-effector transmission in Auerbach's plexus-longitudinal muscle preparation, adenine, guanosine triphosphate and dibutyryl-cyclic AMP had no effect. Theophylline, an adenosine receptor antagonist, prevented the inhibitory effect of the nucleotides. In addition, theophylline alone enhanced the release of acetylcholine both from Auerbach's plexus and from the nerve terminals of the cortical slice. This indicates that there might be a continuous control of ACh release by an adenine nucleotide. These results are discussed in relation to the release of adenosine triphosphate from purinergic nerves in the intestine and of adenosine from slices of cerebral cortex; the possibility is raised that adenine nucleotides released from nerves might act as a type of presynaptic inhibitory transmitter on cholinergic neurons. Furthermore, if some of the released nucleotide originates from the synaptic vesicles of cholinergic neurons, it might serve as a negative feed-back transmitter for acetylcholine release. The inhibitory effect of adenosine and related nucleotides on the cholecystokinin-induced release of acetylcholine from the gut might be of physiological importance since gastrointestinal polypeptides play a very important role in maintaining gastrointestinal motility.

Mechanism of starch-sugar interconversion in Solanum tuberosum

The changes in glucose-1-phosphate, glucose-6-phosphate, fructose-6-phosphate, dihydroxyacetone phosphate, 3-phosphoglycerate, 2-phospho-glycerate, phosphoenol-pyruvate, pyruvate, adenosine mono-, di- and tri-phosphates, NAD and NADH, sugars and respiration of mature potato tubers (variety King Edward) caused by transfer from + 10° to + 2° and back to + 10° were followed throughout 4–8 weeks of storage. The results obtained showed a characteristic two phase pattern. In the case of the transfer from + 10° to + 2° a number of the phosphate esters showed wide individual variations in concentration during the first phase but only slow changes during the second phase when most of the phosphate esters tended to follow a common pattern. In the first phase the sugar concentration remained roughly constant, but in the second a considerable increase in both sucrose and respiration occurred. In the case of potatoes transferred from + 2° to + 10° the two phase character of the results was not so marked. In the case of potatoes transferred from + 10° to + 2° the changes in the phosphate esters in the first phase did not appear to be related to the conversion of starch to sucrose which only occurred to a significant extent in the second phase. Electron micrographs of potato tubers which had been stored at + 2° for 38 days (sugar content 2.4%) showed that the starch grains were still enclosed in a double membrane (amyloplast membrane). Analysis of starch grains prepared by a non-aqueous method from potato tubers stored at + 10° and + 2° indicated that a large part of the K, Na, Cl, citrate and glucose-6-phosphate was inside the amyloplast but that the sugar (storage at + 2°) was outside; sweetening therefore involved the transport of metabolites through the amyloplast membrane. Comparison with other treatments (anaerobiosis, cyanide, ethylene chlorhydrin) which cause sweetening suggested that the regulation of the starch-sugar interconversion was effected at the amyloplast membrane and possibly involved electron transfer. In the case of potatoes which sweetened due to senescence, electron micrographs showed that the amyloplast membranes were disintegrating.

Sweet clover Weevil: Adenosine as a Feeding Stimulant12

Adult Sitona cylindrirollis Fahraeus responded to adenosine in bioassays for feeding-stimulant activity. The molar concentration of adenosine which elicited maximum feeding in the bioassay was less than 1/10 of the sucrose concentration required for maximum feeding. Various purines, pyrimidines, nucleosides, nucleotides, and related compounds were compared with adenosine in bioassays for weevil-feeding stimulant activity. Of all compounds tested, only adenosine triphosphate and adenosine mono phosphate appeared to act as feeding stimulants; at the concentrations used, their activities were substantially lower than that of adenosine. Free adenosine was isolated from leaf extracts of weevil-susceptible Mclilotus officinalis (L.) Lam. by ion-exchange and paper chromatography and was identified by spectrophotometric and paper chromatographic techniques. The quantity of adenosine present, ca. 12 ¼g/leaflet, was sufficient to indicate that this compound probably influences feeding of the weevil on M. officinalis plants.

Hormone-stimulated lipolysis in isolated fat cells from “young” and “old” rats

The biphasic nature of the lipolytic dose-response curve of epinephrine in fat cells from "young" rats (40-45 days) was confirmed. The first phase (Lipolysis I) occurred at concentrations of from 10(-7) m to 3 x 10(-6) m. The second phase (Lipolysis II) occurred at concentrations of from 10(-5) m to 3 x 10(-4) m. Insulin (0.1 mU/ml) abolished Lipolysis I and slightly augmented Lipolysis II. Higher concentrations of insulin (1.0 mU/ml) augmented Lipolysis II even further. These results may help to explain some of the conflicting reports in the literature concerning the effects of insulin on lipolysis. The dose-response curve of epinephrine using fat cells from "old" rats (14-16 months) was monophasic. Based on results with propranolol, K(+)-free media, and insulin, it was concluded that the lipolytic response in tissue from older animals corresponds to Lipolysis II in tissue from younger rats. The lipolytic response to ACTH was greatly reduced in the cells from the older rats, but the response to theophylline was unaltered.

An enzyme system in rat brain nuclei incorporating AMP into polyadenylate.

Abstract— The presence of an ATP polymerizing system has been demonstrated in rat brain nuclei. The enzymic activity was not dependent on DNA, and poly A itself primed the incorporation of AMP into polyadenylate. Poly U did not prime the incorporation of AMP. The incorporation obtained in the presence of ribosomal RNA from rat brain as primer was mainly attributable to terminal attachment of AMP. Actinomycin and inorganic ortho‐phosphate had no effect on the enzymic activity, however, inorganic pyrophosphate, ammonium sulphate and nucleoside triphosphates (GTP, CTP and UTP) were inhibitory. The same nuclear extract of brain, used for the synthetic reaction producing poly A, also degraded the polynucleotide to yield adenosine mono, di and triphosphates.

Acceleration of lipid synthesis in cultured aortic cells by adenosine phosphates.

Effects of adenosine phosphates on lipid synthesis were studied in singular aortic cell culture system, in which a linear relation was shown between the 14C-acetate incorporation and incubation time over 6 hours. Adenosine triphosphate promoted 14C-acetate incorporation into cultured chick aortic intimal cells. The incorporation rate was greater in neutral fat and sterol fraction than in phospholipid fraction. Adenosine mono- and diphosphates as well as adenosine triphosphate accelerated lipid synthesis to the same extent in the aortic cell culture environment.

The Effect of Aldosterone on Glycolysis in the Urinary Bladder of the Toad

Prolonged incubation with aldosterone causes an increase in the rate of sodium transport and in the rate of glycolysis in the urinary bladder of the toad (Bufo marinus) in vitro. When sodium transport was inhibited by ouabain after the effect of aldosterone was manifest, the rate of sodium transport as well as the rate of glycolysis fell to the same low value in aldosterone-treated tissue and in paired control tissue that had been incubated without hormone. When bladders were made anaerobic after the aldosterone effect was manifest, short circuit current fell in both preparations, but remained significantly higher in aldosterone-treated tissue than in paired control tissue. During anaerobiosis, the rate of lactate production was higher in aldosterone-treated tissue than in paired anaerobic control tissue. Thus the effect of aldosterone on glycolysis appears to be related to its effect on sodium transport and does not depend entirely upon oxidative metabolism. Measurement of the concentration of glycolytic intermediates and cofactors in tissue incubated with aldosterone indicated activation of phosphofructokinase and pyruvate kinase. There was no change in the concentration of adenosine mono-, di-, or triphosphate, or inorganic phosphate, but there was a fall in creatine phosphate and a rise in the concentration of creatine in aldosterone-treated tissue. This pattern is interpreted as indicating that the stimulation of sodium transport by aldosterone (or an aldosterone-induced protein) is a direct effect on sodium transport and not secondary to an effect of the hormone on energy production.

Studies of Raman Spectra of Water Solutions of Adenosine Tri-, Di-, and Monophosphate and Some Related Compounds

Using a He-Ne CW laser source together with a digital photon counting system, we have obtained well resolved Raman spectra for adenosine mono-, di-, and triphosphate (AMP, ADP, ATP) in aqueous solution. Spectra of these compounds were studied as a function of pH from pH = 0.5 to 13.5 and between 550 and 1700 cm(-1). It was found possible to distinguish spectroscopically between the three phosphates over the pH range studied. A qualitative analysis of vibrational modes responsible for various spectral lines is given. Lines at about 960 and 1100 cm(-1) were found to be good indications of the degree of ionization of the terminal phosphate group.

Control of Glycogenolysis in the Toad's Urinary Bladder: THE EFFECT OF ANAEROBIOSIS, SODIUM TRANSPORT, AND ARGININE VASOTOCIN

Abstract The control of glycogenolysis in the urinary bladder of the toad (Bufo marinus) in vitro has been examined by measuring the concentration of glycogenolytic intermediates and cofactors in the tissue. When the rate of glycogenolysis was increased by anaerobiosis, metabolite levels indicated activation of phosphofructokinase and pyruvate kinase. The activation of phosphofructokinase was probably secondary to a fall in the concentration of adenosine triphosphate and a rise in the concentration of adenosine mono- and diphosphate and inorganic phosphate. Activation of pyruvate kinase may have been secondary to a fall in the concentration of adenosine triphosphate and a rise in adenosine diphosphate or the rise in the concentration of fructose 1,6-diphosphate or both. Incubation with arginine vasotocin in a Ringer's solution containing sodium stimulated glycogenolysis under aerobic or anaerobic conditions. The hormone caused activation of phosphorylase, phosphofructokinase, and pyruvate kinase without marked changes in the concentration of cofactors. Since arginine vasotocin affects the toad bladder by stimulating adenyl cyclase activity, it is speculated that adenosine 3',5'-monophosphate activates phosphorylase, resulting in a rise in the concentration of fructose 6-phosphate, which in turn activates phosphofructokinase, resulting in a rise in the concentration of fructose, 1,6-diphosphate, which may activate pyruvate kinase. When sodium transport was inhibited by incubating the bladder with ouabain or in a Ringer's solution in which tris(hydroxymethyl)aminomethane ions replaced all of the sodium ions, the rate of glycogenolysis fell as a result of inhibition at phosphofructokinase. There were no significant changes in the concentration of adenosine mono-, di-, or triphosphate or inorganic phosphate. In contrast to experiments in a Na+ Ringer's solution, arginine vasotocin did not stimulate glycogenolysis in bladders incubated in a Tris+ Ringer's solution. Metabolite levels indicated only slight activation of phosphorylase and no activation of phosphofructokinase or pyruvate kinase. Again, no change in the concentration of cofactors was detected. It is concluded that phosphorylase, phosphofructokinase, and pyruvate kinase are glycogenolytic control points in the toad bladder responding to changes in the concentration of cofactors In addition, it is apparent that the rate of sodium transport affects the activity of these enzymes through an unknown pathway.

Regulation of Metabolism in Working Muscle in Vivo: II. CONCENTRATIONS OF ADENINE NUCLEOTIDES, ARGININE PHOSPHATE, AND INORGANIC PHOSPHATE IN INSECT FLIGHT MUSCLE DURING FLIGHT

Abstract The concentrations of adenosine mono-, di-, and triphosphates, arginine phosphate, and inorganic phosphate in flight muscle of the blowfly, Phormia regina, were measured concurrently after periods of flight ranging from 5 sec to 1 hour. At the onset of contraction, the concentrations of ATP and arginine-P decreased, whereas those of ADP, Pi, and especially AMP, increased. The pattern of changes in these phosphates is in accord with the postulated mechanism of glycolytic regulation at the phosphofructokinase step. Possible oscillatory responses induced by the initiation of active contraction in vivo are suggested.

A histochemical and fine structure study of the developing rat choroid plexus.

1. A histochemical and fine structural study of the developing rat choroid plexus was made from 1–3 days before birth to the adult stage. 2. The maturation of the choroidal epithelium is associated with a loss of cytoplasmic glycogen, increasing surface area of the plasma membrane associated with the development of an apparent adenosine triphosphatase activity, and increasing numbers of mitochondria and prominence of the rough endoplasmic reticulum associated with increasing diaphorase and dehydrogenase activity. Following birth, thiamine pyrophosphatase and adenosine mono- and diphosphatase activity appear in the blood vessels. Structures associated with pinocytotic activity are most numerous in young rats. 3. It is suggested that the increased susceptibility of young rats to experimentally produced hydrocephalus is related to the potential of their choroid plexus for active transport.

Content of lactic acid and adenosine mono-, di- and tri-phosphates in anoxic-ischaemic rat brain.

The Journal of Pathology and BacteriologyVolume 90, Issue 2 p. 533-541 Article Content of lactic acid and adenosine monodi- and tri-phosphates in anoxic-ischaemic rat brain R. G. Spector, R. G. Spector The Paediatric Research Unit, Guy's Hospital Medical School, LondonSearch for more papers by this author R. G. Spector, R. G. Spector The Paediatric Research Unit, Guy's Hospital Medical School, LondonSearch for more papers by this author First published: October 1965 https://doi.org/10.1002/path.1700900221Citations: 13AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume90, Issue2October 1965Pages 533-541 RelatedInformation

Fine structural localization of adenine nucleoside phosphatase activity in the sarcoplasmic reticulum and the T system of rat myocardium

Adenosine mono-, di-, and triphosphatase activities were studied in rat cardiac muscle fibers fixed in situ by perfusion of the coronary arteries with glutaraldehyde. Enzymes splitting ATP and ADP were present in the lateral elements of triads and in flattened cisterns found in relation to the intercalated disk and the free surface of the fiber. They are referred to as subsarcolemmal cisterns. With AMP as substrate, reaction product was found in the entire T system, but none was evident in the subsarcolemmal cisterns or in the lateral elements of triads. It is suggested for reasons discussed that the ATPase-containing structures play a role in the excitation-contraction coupling in cardiac muscle cells by energizing an ATP-driven calcium pump.

HISTOCHEMICAL DEMONSTRATION OF CATECHOLAMINE UPTAKE BY ADRENERGIC FIBERS.

Uptake of catecholamines by adrenergic fibers was tested in isolated rat irises using the histochemical formaldehyde condensation technique. Minimum concentration in medium for detectable uptake was 0.5 µg/ml for the naturally-occurring catecholamines norepinephrine, epinephrine and dopamine. Adenosine mono-, di-, or triphosphate in minimum concentration of 0.01 µg/ml was required for amine uptake. Parallel specific chemical analyses confirmed the uptake of norepinephrine and epinephrine shown histochemically.

Further observations on platelet aggregation induced by adenosine diphosphate thrombin and tri-ethyl tin

Aggregation induced by adenosine diphosphate is inhibited by adenosine as well as by adenosine mono- and triphosphate. Thrombin-induced aggregation is also inhibited by adenosine and the monophosphate, but the triphosphate at a similar concentration is not inhibitory. Aggregation induced by tri-ethyl tin is accelerated by a critical concentration of triphosphate and delayed by a higher concentration. The tri-ethyl tin effect is inhibited by 5-hydroxytryptamine and by tryptamine. Platelets from patients treated with reserpine respond normally to these last two substances. Incubated platelets lose first their ability to respond normally to tri-ethyl tin, then to thrombin, and lastly to adenosine diphosphate. These results are briefly discussed.

Local effect of adenosine mono-, di-, and triphosphate vessel resistance.

The local effects of adenosine mono-, di-, and triphosphate (AMP, ADP, and ATP) on resistance to blood flow through large and small vessels of the forelimb were studied in 14 anesthetized dogs. This was accomplished by holding blood flow constant to the forelimb while pressures in the brachial artery, cephalic vein, and a small artery and vein in the forepaw were recorded. Acute local elevation of plasma AMP, ADP, and ATP concentration greatly decreased resistance to blood flow in the small vessels over a wide dose range. It is concluded that AMP, ADP, and ATP act primarily on small vessels, and particularly arterioles, to produce active vasodilatation.

Biochemistry of the developing rat brain I. Soluble enzymes in isolated neonatal brain nuclei

A procedure is described for the isolation of neonatal rat-brain nuclei free of debris using a Triton X-100-sucrose medium for homogenization to facilitate removal of erythrocytes and cytoplasmic organelles. The isolated nuclei swell in water without rupture indicating that the nuclear membranes were intact. To rupture these nuclei it was necessary to use 1 M Tris buffer.Assays of the nuclear extracts established the presence of the glycolytic enzymes. Thus, generation of ATP from ADP occurs by the action of triose phosphate dehydrogenase and pyruvate kinase. Adenylate kinase and ATPase were also present in these extracts, which suggests that they act as a means for maintaining the required levels of adenosine mono- and polyphosphates in the nuclei.NADP-isocitric dehydrogenase and malic dehydrogenase were also found in the nuclear extracts, however, their role in nuclear metabolism is unknown.