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1.
Cyclic adenosine monophosphate stimulation of axonal elongation   总被引：11，自引：0，他引：11  
Elevated concentrations of adenosine 3',5'-monophosphate induce a variety of cell movements. The role of adenosine 3',5'-monophosphate in promoting those movements associated with growth prompted our study of in vitro microtubule-dependent axonal elongation. Ganglia treated with adenosine 5'-monophosphate show no enhancement over controls; treatment with adenosine 3', 5'monophosphate or its dibutyryl derivative significantly enhances elongation, as measured by increases in both axonal numbers and length. Our study suggests that adenosine 3',5'-monophosphate promotes elongation by stimulation of microtubule assembly.  相似文献   

2.
Osmotic release of beta-glucuronidase from polymorphonuclear leukocyte lysosomes is inhibited by catecholamines and adenosine 3',5'-monophosphate, and accelerated by cholinergic agents and guanosine 3',5'-monophosphate. These actions are specific for the sympathetic and parasympathetic neurotransmitters and for the two cyclic nucleotides, as phenylephrine, tyramine, choline, adenosine 5'-monophosphate and guanosine 5'-monophosphate do not inodify lysosomal enzyme release.  相似文献   

3.
Adenosine 3',5'-monophosphate stimulated production of carbon dioxide and lipid from glucose, whereas its dibutyryl derivative inhibited this conversion. Addition of the dibutyryl derivative to the isolated fat cell further stimulated lipolysis induced by adrenocorticotropic hormone, whereas addition of adenosine 3',5'-monophosphate inhibited this lipolysis. Hence, measured by these two parameters, the biologic properties of adenosine 3',5'-monophosphate and its dibutyryl derivative are distinctly different.  相似文献   

4.
Treatment of cultured rat pineal glands with norepinephrine or dibutyryl adenosine 3',5'-monophosphate causes a six- to tenfold stimulation of N-acetyltransferase. This enzyme converts serotonin to N-acetylserotonin, the immediate precursor of melatonin. The increased synthesis of melatonin caused by norepinephrine treatment appears to be the result of stimulation of N-acetyltransferase by an adenosine 3',5'-monophosphate mechanism.  相似文献   

5.
The acellular slime mold Physarum polycephalum releases a soluble adenosine 3', 5'-monophosphate phosphodiesterase into the growth medium. Although this enzyme resembles the particulate diesterase of the same organism in kinetic properties and in inhibition by methyl purines, its greater stability, its insensitivity to stimulation by imidazole and to inhibition by adenosine triphosphate,- and its selective release into the medium indicate a specific function, perhaps protection against exogenous cyclic nucleotide, for the soluble enzyme.  相似文献   

6.
Two positional isomers (9 and 11) of trans octadecenoates did not support growth on glucose of an Escherichia coli mutant that requires unsaturated fatty acids. However, the trans fatty acids provided sufficient fluidity to produce much higher cell yields when the concentration of adenosine 3',5'-monophosphate was raised. The effectiveness of the trans acids rose from 0 to 1 cell per femtomole to 15 to 20 cells per femtomole as the concentration of adenosine 3',5'-monophosphate was increased. The corresponding cis positional isomers supported high yields (35 to 40 cells per femtomole) independent of supplementation. The enhanced growth with adenosine 3',5'-monophosphate supplementation is not due to an increased uptake and incorporation of the trans isomers relative to the cis isomers, since the 9-trans isomer was incorporated more rapidly than the 9-cis isomer into the membrane phospholipids under all growth conditions and represented 21 +/- 2 mole percent of the acids. The finding that cells growing with trans fatty acid isomers have a higher requirement for adenosine 3',5'-monophosphate may indicate that some fatty acids can alter the metabolic regulation normally exerted by the cyclic nucleotide.  相似文献   

7.
Inhibition of cell growth in vitro by adenosine 3',5'-monophosphate   总被引：18，自引：0，他引：18  
Adenosine 3',5'-monophosphate, at a concentration of 40 micrograms per milliliter, inhibits the growth of HeLa and strain L cells in culture. The inhibition becomes progressively greater during the incubation of the cells. Adenosine 5'-monophosphate and adenosine, metabolites of adenosine 3',5'-monophosphate, do not affect the growth of either cell culture. This suggests that 3',5'-monophosphate enters the cell without alteration. Dibutyryl-adenosine 3',5'-monophosphate, reported to have a greater activity than adenosine 3'5'-monophosphate on several tissues, inhibited the growth of the cells much less.  相似文献   

8.
The synthesis of a highly fluorescent analog of adenosine 3',5'-monophosphate, namely, 1,N(6)-ethenoadenosine 3',5'-monophosphate, has provided a powerful probe for systems involving adenosine 3',5'-monophosphate. The potential utility of this analog is indicated by its long fluorescent lifetime, detectability at low concentration, and relatively long wavelength of excitation (300 nanometers). In protein kinase systems it is a highly acceptable substitute for adenosine 3',5'-monophosphate.  相似文献   

9.
Human neutrophilic leukocytes release neutral protease and beta-glucuronidase during cell contact with, and phagocytosis of, zymosan particles treated with rheumatoid arthritic serum. Release of lysosomal enzymes is inhibited by epinephrine and adenosine 3',5'-monophosphate (cyclic AMP), but not by phenylephrine or adenosine 5'-monophosphate. Inhibition of enzyme release by epinephrine may be mediated by cyclic AMP because the cyclic AMP in the neutrophils is increased by epinephrine treatment at the time when enzyme release is reduced.  相似文献   

10.
Extracellular histamine stimulates accumulation of adenosine 3',5'-monophosphate in human leukocytes and prevents antigenic release of histamine from cells of allergic donors. Both effects occur at histamine concentrations that can be achieved by antigenic release of the amine in vitro.  相似文献   

11.
Vasoactive intestinal peptide stimulated the synthesis of adenosine 3',5'-monophosphate in fractions of isolated carp horizontal cells. When applied extracellularly to isolated and cultured horizontal cells, the peptide also induced a slow depolarization (30 to 40 millivolts) accompanied by a decrease in membrane resistance. However, analogs of adenosine 3',5'-monophosphate applied extracellularly or intracellularly, and forscolin applied extracellularly, had no effect on the membrane potential of cultured horizontal cells, indicating that the induced depolarization was not related to the accumulation of adenosine 3',5'-monophosphate in these cells.  相似文献   

12.
Synaptic potentials and changes in resting membrane potentials of superior cervical ganglia of the rabbit were measured in the presence of adenosine 3',5'-monophosphate and agents that affect its metabolism. Adenosine 3',5'-monophosphate and its mono- and dibutyryl derivatives caused a hyperpolarization of the postganglionic neurons. Theophylline potentiated the slow inhibitory postsynaptic potential that follows synaptic transmission, as well as the hyperpolarization of postganglionic neurons caused by exogenous dopamine. Conversely, prostaglandin E(1) inhibited both the slow inhibitory postsynaptic potential and the dopamine-induced hyperpolarization. We hypothesize that the slow inhibitory postsynaptic potential as well as the dopamine-induced hyperpolarization result from increased amounts of adenosine 3'5'-monophosphate in the postganglionic neurons. The dibutyryl derivative of guanosine 3'5'-monophosphate caused a depolarization of the postganglionic neurons, which is consistent with the possibility that guanosine 3'5'-monophosphate mediates synaptic transmission at muscarinic cholinergic synapses.  相似文献   

13.
Nerve growth factor and N(6),O(2)' dibutyryl adenosine 3',5'-monophosphate both stimulate neurite elongation by explanted ganglia. However, the addition of nerve growth factor does not lead to increased amounts of adenosine 3',5'-monophosphate in intact ganglia, nor does it stimulate adenylate cyclase activity in broken ganglia cells.  相似文献   

14.
The concentrations of adenosine 3',5'-monophosphate and adenosine triphosphate and the activity of phosphodiesterase were determined in different regions of chick embryos at the head process stage. Adenosine 3',5'-monophosphate, adenosine triphosphate, and phosphodiesterase were estimated to be higher in the mesoderm-forming portions of the hypoblast than in portions that form neural structures from Hensen's node or the epiblast.  相似文献   

15.
Administration of adenosine 3',5'-monophosphate with theophylline produced testosterone-like induction of hexokinase, phosphofructokinase, pyruvate kinase, and glucose-6-phosphate dehydrogenase in the seminal vesicles of both orchidectomized and immature rats. The N(6)-O(2)'-dibutyryl analog of this cyclic nucleotide produced greater increases in vesicular enzyme activities than those induced by the parent compound. The observed enhancement of the key glycolytic enzymes and of hexose monophosphate shunt dehydrogenase was significantly inhibited by actinomycin D and cycloheximide. The evidence indicates that cyclic adenosine monophosphate may be involved as an intermediary in the action of androgenic hormones on male accessory sex organs.  相似文献   

16.
Intragastric administration of glucose inhibits the induction of serine dehydratase and tyrosine aminotransferase by glucagon in rat liver, but has no effect on the increase in hepatic adenosine 3',5'-monophosphate resulting from administration of glucagon. Thus, glucose repression in mammalian liver, unlike catabolite repression in microorganisms, appears to operate independently of the amounts of cyclic nucleotide in the cells.  相似文献   

17.
Bursting pacemaker activity in nerve cells can be modified for long periods by synaptic input of short duration. There is evidence that cyclic nucleotides may play a role in these modifications. The predominant effect of elevated levels of adenosine 3',5'-monophosphate in Aplysia neurons was an increased slope conductance to hyperpolarizing pulses, evident in voltage clamp records. A similar increase in slope conductance was seen as one component of maximum strength synaptic stimulation, which is consistent with the idea that cyclic nucleotides are important in the expression of synaptic alteration of bursting pacemaker activity.  相似文献   

18.
In organ cultures of intact rat pineal glands, N(6)O(2')-dibutyryl adenosine 3', 5'-monophosphate stimulates the conversion of tritiated trytophan to tritiated melatonin, as does L-norepinephrine. Potential sites of stimulation of melatonin production by dibutyryl cyclic adenosine monophosphate are discussed, based on observations that the dibutyryl analog also stimulates the conversion of serotonin labeled with carbon-14 to carbon-14-labeled melatonin without altering hydroxyin-dole-O-methyl transferase activity or intracellular accumulation of serotonin labeled with carbon-14.  相似文献   

19.
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20.
Adenosine 3',5'-monophosphate at a concentration of 5 x 10(-7) mole per liter causes a 400 percent increase in the rate of phosphorylation of histone catalyzed by a partially purified enzyme preparation from rabbit brain. The data provide the first direct evidence of a biochemical action of adenosine 3',5'-monophosphate in the brain.  相似文献   

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