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)

1. The fatigue in rat anterior tibial (a.t.) motor units was studied and related to microphotometric determinations of succinate dehydrogenase (SDH) activity of the motor unit muscle fibres. 2. Anterior tibial contains fast-twitch type II fibre units with an average contraction time of 11 msec and about 5% slow-twitch type I fibre units with an average contraction time of 20 msec. 3. In type II fibres stained for SDH, absorbance varied continuously from 0.046 to 0.569 and inversely to fibre size, except for the largest fibres. 4. Resistance to fatigue of fast motor units to 100 Hz intermittent stimulation varied continuously within a wide range in near linear relations to absorbance for SDH of unit fibres and inversely to tetanic tension, except for motor units with the largest fibres and the largest tetanic tension. 5. Neither resistance to fatigue nor SDH activity lent itself to any categorization of motor units or fibres into well demarcated functional or histochemical types, since both parameters varied continuously in the unit and fibre population of the muscle. 6. The direct relation between resistance to fatigue of fast-twitch motor units and SDH activity of unit fibres appeared valid for fatigue resistance of: (a) neuromuscular transmission, tested with 100 Hz intermittent stimulation which gave concomitant failure of electrical and mechanical response, (b) excitation--contraction coupling, demonstrated by post-stimulatory depression of twitch tension with preserved maximum tetanus tension and action potential, and (c) contractile mechanism; excitation--contraction coupling?, tested with low frequency stimulation which gave decline of twitch and maximum tetanus tension with preserved action potential. 7. It is suggested that the endurance of each link in the chain of events leading to contraction, including neuromuscular junction and the excitation--contraction coupling system, is under aerobic conditions matched to the contractile capacity of the fibre expressed by its oxidative enzyme activity.
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PMID:Transmission and contraction fatigue of rat motor units in relation to succinate dehydrogenase activity of motor unit fibres. 22 67

A study was made of various series of cholerogen on the cultures of human continuous cells of normal (F1, Rh) and tumour nature (HeLa). Cholerogen proved to produce a marked toxic action on the cultures of F1, Rh and HeLa cells causing a reduction of the number of living cells, depression of mitotic activity, a reduction of the intensity of staining on the sum total protein and RNA, a reduction of the activity in the cells of acid phosphatase and succinic dehydrogenase, and also a reduction of production of protein-polysaccharide layer. Different cholerogens produced a different toxic action on the cells of the same type.
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PMID:[Effect of cholerogen on tissue culture cells]. 96 Dec 65

The authors determined polarographically the intensity of oxygen consumption and the activity of succinic dehydrogenase of the HEp-2 cell culture infected with the association of the Cocksackie B3 with the RNA-asopositive and RNA-asonegative strains of E. coli O--111, in comparison with the uninfected and separately infected virus or control bacteria. The results were recorded 2, 6, 12, 18 and 24 hours after the infection of the cell cultures. Mixed virus-bacterial infection intensified the oxygen consumption and the activity of succinic dehydrogenase by the HEp-2 cells, followed by a profound respiratory depression. The same effect was produced by the infection of cells by the virus alone. Less pronounced was the action of bacterial component. A change in the cell repiration of the infected cultures was independent of the RNA-ase activity of bacteria. Under conditions of mixed infection the intensity of the changes in oxygen consumption and of the succinic dehydrogenase activity was determined by the viral component of the association.
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PMID:[Effect of a mixed E. coli O-111 (RNA-azopositive and RNA-azonegative strains) and Coxsackie B3 viral infection on oxygen demand and on the succinate dehydrogenase activity of an HEp-2 cell culture according to polarographic study data]. 110 26

Chronic experiments were conducted on sexually mature rats; histochemical study of the activity of some redox enzymes (glutamic dehydrogenase, lactic dehydrogenase, glucoso-6-phosphoric dehydrogenase, glycerophosphoric dehydrogenase, and succinic dehydrogenase) was carried out in the ependymal cells of the floor of the third cerebral ventricle, the so called tanycytes, in case of an increased adrenocorticotrophic function of the hypophysis attained by bilaterial adrenalectomy, and in depression of this function as a result of chronic dexametasone administration. The activity of the enzymes under study decreased 2, 3 and 4 weeks after bilateral adrenalectomy. The activity of lactic dehydrogenase, glucerophosphoric dehydrogenase and succinic dehydrogenase increased in the tanycytes during administration of 5 gamma of dexametasone. Chronic administration of 100 gamma of dexametasone was accompanied by a toxic action of the preparation (a marked reduction in the weight of the adrenal glands, a negative body weight gain, and an aggravation of the animal's general condition). The results obtained pointed to the existence of a reverse correlation between the metabolic activity of tanicytes and the adrenocorticotrophic function of the hypophysis.
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PMID:[Histochemical study of tanycytes in connection with the adrenocorticotropic function of the hypophysis]. 114 24

Six different lipophilic (hydrophobic) organic cations, tetraethyl-, tetrapropyl, tetrabutyl-, tetrapentyl-, tetrahexyl-, and tetraheptylammonium bromide, depressed respiratory control in rat liver mitochondria. Evaluation of mitochondrial responses in terms of a quadratic equation in log P (an index of lipophilicity) indicated that the NADH dehydrogenase receptor site for inhibitor (diminution of control of glutamate, alpha-ketoglutarate, and beta-hydroxybutyrate respiration) was more lipophilic than receptor sites for flavin-linked substrates (reduction of control of succinate, choline and alpha-glycerophosphate respiration). The succinate dehydrogenase receptor site for inhibition by the tetraalkylammonium bromides was more hydrophillic (less lipophilic) than the choline or alpha-glycerophosphate dehydrogenase receptor sites. Depression of respiratory control may be a function of charge density and of lipophilicity at specific inner membranal sites and the susceptible site may differ for different respiratory substrates.
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PMID:Respiratory control depression by tetraalkylammonium bromides in rat liver mitochondria. 124 57

1. Transmitter release at neuromuscular junctions of extensor digitorum longus (EDL) muscle in mice was studied after 2-8 month periods of unforced running in wheels. 2. Intracellular recordings at 10 Hz stimulation revealed that the quantal content of endplate potentials (EPPs) in Mg(2+)-blocked preparations was larger by 30% in trained (mean number of quanta, m = 1.75 +/- 0.19, n = 7) than in untrained control EDL muscles (m = 1.35 +/- 0.35, n = 7). Similarly the amplitudes of the first, maximum and plateau EPPs during tetanic stimulation (100 Hz for 1 s or 400 ms) in curare-blocked preparations were increased by 28% each; muscle fibre diameters did not differ while other postsynaptic effects were not excluded. 3. Training effects became particularly evident in two pairs of monozygotic twins, in which the time courses of facilitation and depression were changed as well: at 100 Hz stimulation the maximum EPP amplitude was reached on average at 2.6 impulses in controls but at 2.0 impulses in runners, and the following decline below the value of the first EPP at 5.0 and 3.8 impulses respectively. 4. Block resistance, as monitored by isometric tension measurements in different presynaptic (Mg2+) and postsynaptic (curare) blocking solutions, was higher in trained than in control EDL muscles. Depression in a train of four nerve-evoked single twitches at 2 Hz was lower. 5. As expected from the unchanged fibre diameters (see above) isometric tetanic force was similar in trained and control EDL muscles. Muscle fatigue resistance was larger in trained animals and succinic dehydrogenase activity was higher in fibres of trained muscles indicating an endurance training of the EDL muscle. 6. It is concluded that besides changes in muscle fibre properties, prolonged elevated activity causes increased transmitter release in EDL muscles. As a consequence, the safety margin of transmission in trained EDL muscles is markedly elevated.
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PMID:Effects of enhanced activity on synaptic transmission in mouse extensor digitorum longus muscle. 164 30

Saline extracts of burn eschar (CEBE) and normal skin (CENS) caused inhibition to mitochondrial respiration and inner membrane function. Ethyl acetate extracts from CEBE (D1) and CENS (D'1) caused depression of the Respiratory Control Ratio, (RCR), an inhibition of respiration rate in state 3 and stimulation to state 4 respiration. Excellent linear correlations exist between the degree of inhibition to state 3, rate of stimulation to state 4 respiration and the logarithm of doses of D1 and D'1. The effective dose ranges (0.75-0.25 mg/ml for D1 and 4-1 mg/ml for D'1) differ by one order of magnitude. The activity of NADH dehydrogenase and succinate dehydrogenase of mitochondria after incubation with the highest toxic dose of D1 or D'1 remained normal. Dinitrophenol (DNP)-stimulated respiration was moderately inhibited by D1 and D'1. No change of oligomycin-sensitive ATPase activity was demonstrated. Exogenous malondialdehyde (MDA) did not show any inhibitory effect. Preliminary studies show that D1 contains a family of free fatty acids (FFA). Incubation of normal mitochondria with D1 increased the content of saturated FFA and a decrease of unsaturated FFA. The role of other peroxidative products is under investigation.
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PMID:Inhibition of mitochondrial respiratory function by an organic solvent extractable component from an extract of burn eschar. 183 77

A reduction in exercise capacity is a common feature of congestive heart failure. We hypothesized that depressed aerobic enzyme activity of skeletal muscle may contribute to this exercise intolerance. Biopsy samples of vastus lateralis muscle were obtained from seven patients with severe chronic heart failure and analyzed for aerobic enzyme activity. Compared with normal laboratory controls, the patients with heart failure had a moderate reduction (greater than 60%) in skeletal muscle citrate synthase and a marked reduction (greater than 90%) in succinate dehydrogenase and cytochrome oxidase (all p less than 0.001). Depression of aerobic enzyme activity of skeletal muscle is associated with severe chronic heart failure and is likely one of the contributory factors for impaired exercise capacity seen in the advanced stages of this condition.
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PMID:Depressed aerobic enzyme activity of skeletal muscle in severe chronic heart failure. 185 Apr 46

To study the extent, duration, and localization of metabolic changes in vein-to-vein grafts in rats, the sequential changes in enzymatic activity of veno-venous grafts in rats were evaluated by histochemical demonstration of the activity of two oxidoreductases (lactate dehydrogenase and succinate dehydrogenase) and two hydrolytic enzymes (adenosine triphosphatase and alkaline phosphatase). All the enzymes studies showed a decrease in staining 1 day after transplantation, the change being most pronounced for AFOS in the subendothelial layer. The recovery of staining intensity was noted after 3 days, the enzyme activity reaching the pregrafting level at 1 week. Different from the previous observations on vein-to-artery grafts, these vein-to-vein grafts showed less depression of enzyme activity during the first days after transplantation, neither did they display a continuing strong activity later on, probably due to lack of a thickening intimal layer.
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PMID:Enzyme histochemical studies on veno-venous grafts in rats. 252 65

Functional and structural alterations of myocardial mitochondria were investigated after four conditions of myocardial ischaemia in guinea pig heart: (1) 45 min complete ischaemia, (2) 60 min low-flow anoxic perfusion (0.3 ml/g wet weight per minute) with a modified Tyrode solution, (3) as (2) with 0.4 mM palmitic acid added to the perfusate, and (4) as (2) with 0.4 mM oleic acid added. Under conditions (1) and (2) the loss of tissue ATP (20-30% of aerobic control) and the degree of mitochondrial injury were similar. But when fatty acids were present during low-flow anoxia, ATP loss and mitochondrial injury were more severe. Oleic acid caused greater injury than palmitic acid. The extent of mitochondrial injury corresponded to variations in mitochondrial long-chain acyl CoA content. Compared to aerobic control values, acyl CoA was increased 1.5 fold under condition (1), not significantly altered under condition (2), increased 3.2 fold under condition (3) and increased 4.3 fold under condition (4). In low-flow anoxia fatty acids enhanced the depression of oxidative phosphorylation, the loss of cytochromes, the inhibition of adenine nucleotide translocase and the reduction of mitochondrial Ca2+ sequestration. Fatty acid induced injury differed in quality from that of conditions (1) and (2): complex II dependent respiration was markedly affected, cytochrome b was lost extensively, and cytochrome oxidase activity was distinctly reduced. The results indicate that fatty acids, when administered to ischaemic myocardium, interfere with mitochondrial membranes at several sites, probably by their CoA esters. The more lipophilic oleyl moiety has a greater effect than the palmityl moiety.
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PMID:Detrimental actions of endogenous fatty acids and their derivatives. A study of ischaemic mitochondrial injury. 282 81


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