Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

NH4Cl was infused into the left renal artery of anesthetized dogs at 50-125 mum/kg/min for up to 110 min. Renal blood flow declined early then increased to supra-control levels during infusion. Kidneys perfused at 125 mum/kg/min for 90 min showed patchy to confluent mixtures of cortical necrosis and tubular necrosis. Experimental kidneys invariably showed lower urine osmolality than contralateral controls 48 h after perfusion. Kidneys with necrosis showed depressed creatinine clearance as well. Renal artery infusion of NH4 acetate or intravenous infusion of NaHCO3 during arterial infusion of NH4Cl prevented significant acidosis and caused minimal histological changes, but depression of urine osmolality was not prevented. It is concluded that renal ammonium concentrations up to 40 mum/liter for 90 min does not cause tubular necrosis but does impair urine concentration. Severe tissue damage followed renal exposure to high ammonium concentrations in the presence of metabolic or renal acidosis.
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PMID:Some effects of ammonium salts on renal histology and function in the dog. 0 Jun 32

The effect of ammonium on glutamine synthetase of fodder yeast Candida tropicalis was studied. Ammonium ions were found to repress the synthesis of glutamine synthetase of fodder yeast and to inhibit the enzyme in the cells. The substitution of glutamic acid for ammonium in the nutrient medium brought about depression of glutamine synthetase.
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PMID:[Regulation of glutamine synthetase of the fodder yeast Candida tropicalis by ammonium ions]. 0 35

Asparagine was a superior nitrogen source for clavine-alkaloid production in Claviceps purpurea. Its transport into the cell excedded the cell's biosynthetic need for this amino acid. Asparagine entered the cell without degradation. This disturbed the relative pool sizes of various amino acids resulting in a change in the genetically determined ratio at which amino acids were utilized for protein synthesis. Overproduction of alkaloids (4500 mug.ml-1) may be associated with increased availability of tryptophan because of the enhanced assimilation of asparagine-derived ammonia via glutamine synthetase (EC 6.3.1.2). However, ammonium salts in the fermentation broth led to a depression of the alkaloid yield. Partial replacement of the ammonium salt by aspartic acid elevated alkaloid production.
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PMID:The cellular role of nitrogen in the biosynthesis of alkaloids by submerged culture of Claviceps purpurea (Fr.) Tul. 1 58

Experiments on cats determined that ammonium acetate injected intravenously (2-4 mM/kg) supressed the processes of primary afferent depolarization (PAD) which are thought to be responsible for the presynaptic inhibition of spinal reflexes. The supression was transient and proceeded in paralle to depression of postsynaptic inhibition of monosynaptic reflexes. Ammonium acetate slightly decreased the amplitude of the negative postsynaptic potentials recorded form the dorsal surface of lumbar cord in response to stimulation of hind limb afferent nerves and increased polysynaptic reflex discharges in appropriate ventral roots. These findings make it unlikely that the ammonium depression of PAD is a result of impairment of interneuronal activity. A suggestion is made that ammonium depression of PAD results from diminition of the EMF for synaptic currents producing PAD.
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PMID:[Effect of ammonium acetate on depolarization processes in the central terminals of primary afferents]. 19 May 47

Myocardial levels of ammonia, glutamate, and glutamine and the release of glutamate and glutamine were studied in the isolated perfused rat heart during perfusion with ammonium chloride, epinephrine, and conditions of anoxia or ischaemia. Perfusion for 15 min with effective ammonium chloride concentrations of 0.53, 0.71, and 2.06 mmol/l resulted in glutamine production of 1.34, 0.95, and 4.41 mmol with 15 min-1/200 dry weight compatible with the presence of glutamine synthetase in rat myocardium. Myocardial ammonium content was unchanged by perfusion with 0.53 and 0.71 mmol/l ammonium chloride, but was increased by 1.36 mumol with 15 min-1/200 mg dry weight by perfusion with 2.06 mmol/l ammonium chloride. Increased myocardial contents of ammonia and glutamine were not accompanied by depression of left ventricular pressure. Perfusion with epinephrine (0.20 mug/ml) resulted in an increased myocardial content of glutamine. Anoxia or ischaemia resulted in no changes in ammonia content, and no changes in glutamine or glutamate production. The net release of glutamine into the perfusate was about 10 times the net release of glutamate.
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PMID:Glutamine production by the isolated perfused rat heart during ammonium chloride perfusion. 24 May 5

A specific inhibitory activity of in vitro proliferative responses of normal human lymphocytes to Candida metabolic antigen was found in the serum of 6 out of 23 children with chronic mucocutaneous candidiasis. In each of the six patients, the presence of an inhibitory activity was associated with Candida-specific cellular defects, characterized by a negative-skin test and a lack of in vitro lymphocyte proliferation. The presence of a circulating inhibitor was detected during relapses of the disease and disappeared under antifungal therapy. This inhibitory effect was not associated with any toxicity on tested lymphocytes. The factor was shown to be nondialysable, thermostable, nonprecipitable with ammonium sulfate and absorbable on anti-Candida antibodies or concanavalin A-coupled agarose columns. Altogether, these results suggest that the inhibitory factor is not an immunoglobulin, but rather a polysaccharidic antigen of Candida albicans. An inhibition of Candida-induced proliferative response of normal human lymphocytes was also obtained by addition of polysacharide antigens or purified mannans from C. albicans to cultures. Candida polysaccharidic antigens appeared, therefore, to be involved in specific depression of cellular functions observed in chronic candidiasis.
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PMID:Specific inhibition of in vitro Candida-induced lymphocyte proliferation by polysaccharidic antigens present in the serum of patients with chronic mucocutaneous candidiasis. 36 54

Perfusion of the central canal of the lumbar segment of the spinal cord with artificial cerebrospinal fluid (CSF) supplemented with ammonium ions induced in cats depression of slow negative electrotonic potentials of dorsal roots (PDR). PDR depression developed simultaneously with postsynaptic depression of the inhibition of monosynaptic reflexes, however it was not related to the depression of mono- or polysynaptic reflex discharges. Further perfusion of the central canal with normal CSF resulted in a complete restoration of the PDR as well as inhibition of control reflexes. It is suggested that PDR depression with ammonium ions could be the result of the blocking of the chloric pump acting the afferent terminals and creating electromotive power for outward transmembranous chloric current producing depolarization of the afferent fibres.
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PMID:[New evidence of depression of depolarization of primary afferents with ammonium ions]. 49 74

The effects of various cations on the water unit activity were studied by recording unitary discharges in the superior laryngeal nerve fibers of the rabbit. Chloride salts of Li+, Na+, K+, Cs+ depressed the water response, while sulfate salts of Li+, Na+, NH4+, K+ facilitated it. Cations were less effective in stimulating action than anions. The depression of the water response in the laryngeal nerve has been thought to be caused by permeation of the stimulating anions through the receptor membrane and/or by destruction of the water structure on the membrane surface induced by adsorbed anions (SHINGAI, 1977 a). In order to differentiate these two possible actions of anions, the effects of benzenesulfonate and trichloroacetate were examined, because these anions were expected to be impermeant through the receptor membrane and to have a water structure-breaking effect. These anions showed no effect on the water response in concentrations below 320 mM. Measurements of the viscosity and the density of the electrolyte solutions showed that benzenesulfonate had a strong water structure-breaking effect. These results suggested that impermeant anions having water structure-breaking actions do not influence the excitability of the water receptor and that the depression of the water response by anions in the stimulating solution is caused by a hyperpolarization generated by permeation of the anions through the receptor membrane.
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PMID:Physicochemical study of receptive mechanism of laryngeal water fibers in the rabbit. 53 47

We have devised an improved high pressure liquid chromatographic technique whereby serotonin, nucleosides, cyclic nucleotides, namely cAMP and cGMP, and 5'mono-, 5'di-, and 5'tri-nucleotides can be analyzed. The cyclic nucleotides have been measured in picomolar quantities. All nucleotides can be quantitated in a single step separation in 75 min using a 0.0015 M phosphoric acids vs. 1M pH 4.8 ammonium phosphate gradient. 5/10 ml of platelet-rich plasma furnishes an adequate sample for complete analysis. Nucleotide levels in platelets from 16 normal donors expressed in 10(11) platelets are as follows: cAMP, 6.32 (4.15) nanomoles and AMP, 0.32 (0.14); ADP, 2.48 (0.67); ATP 3.78 (0.68); GDP 0.38 (0.07) and GTP, 0.45 (0.07) micromoles. ADP and ATP values are lower than those previously published. However, the total nucleotide level approaches published values. Upon aggregation with thrombin, approximately 50% of ADP and 40% ATP is releaseed. Release is complete by 2 min. Thrombin is the most potent releasing agent with collagen and ADP occupying an intermediate role and epinephrine being the least effective. Upon aggregation cyclic AMP levels diminish along the other nucleotides. Patients with asthma showed depression of ADP, ATP, GDP and GTP levels.
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PMID:Measurement of nucleotide pools in platelets using high pressure liquid chromatography. 57

Changes in electrocardiograms, blood pressure, pH, and partial pressure of gases (Po2 and Pco2) in arterial blood were studied in goats poisoned by urea or ammonium compounds under spontaneous and artificial respiration and in nonconvulsive state. Abnormal electrocardiogram patterns, such as ventricular flutter, ventricular premature beat, atrioventricular dissociation, depression of ST-segment and sinus tachycardia, were all observed after the occurrence of tetanic convulsion. The electrocardiogram pattern seen at the respiratory arrest showed sinus or supraventricular tachycardia; respiratory arrest preceded cardiac arrest in all the goats, but one. Blood pressure was markedly elevated, accompanied with tetanic convulsion. Po2 decreased gradually and the level was below 30 mm Hg (37.0 degrees C) at respiratory arrest and the final opisthotonus. Artificial respiration starting at the final opisthotonus could delay the cardiac arrest. Under nonconvulsive urea-poisoning with gallamine triethiodide and with artificial respiration of air or a mixture of air and oxygen to elevate the Po2 level, changes of electrocardiogram, blood pressure, and Po2 were similar to those seen under convulsive urea-poisoning. The main cause of death was discussed and presumed to be respiratory and cardiovascular failure.
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PMID:Electrocardiographic observation on goats with urea-ammonia poisoning and a consideration on the main cause of death. 60 86


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