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. Repetitive stimulation (10-20 Hz, 0.5-5 s duration) of the preganglionic nerves to ganglia on the surface of the urinary bladder of the cat produced a prolonged inhibition (duration, 30-65 s) of the postganglionic action potentials, elicited by low-frequency stimulation (0.25-1 Hz) of another preganglionic nerve to the same ganglion. 2. Intra-arterial administration of naloxone, an opiate antagonist (20-50 micrograms/kg), reduced the magnitude and duration of this heterosynaptic inhibition and also blocked the depression of ganglionic transmission elicited by the intra-arterial administration of leucine-enkephalin (0.1-10 micrograms/kg). 3. Naloxone did not alter adrenergic inhibition elicited by repetitive stimulation of the hypogastric nerve or exogenous noradrenaline. Naloxone did not alter the postganglionic firing elicited by single stimuli or trains of low-frequency (1-3 Hz) stimuli to the preganglionic nerves. 4. Heterosynaptic inhibition was not altered by the administration of antagonists for alpha-adrenergic (dihydroergotamine, prazosin, yohimbine), muscarinic (atropine), purinergic (theophylline) or GABAergic (picrotoxin) receptors. 5. A delta-selective opiate receptor agonist, DSLET (D-Ser2-leucine-enkephalin-Thr), inhibited parasympathetic ganglionic transmission in low doses (mean threshold dose, 0.02 microgram/kg, I.A.), whereas a mu-opiate receptor agonist, morphine sulphate, produced only a small depression in larger doses (mean threshold dose, 100 micrograms/kg, I.A.). Ethylketocyclazocine, which has an affinity for kappa-receptors did not alter transmission in relatively large doses (1 mg/kg, I.A.). 6. These findings coupled with previous immunocytochemical demonstrations of leucine-enkephalin-like immunoreactivity in preganglionic nerve terminals in bladder ganglia suggest that opioid peptides released endogenously from preganglionic nerves are involved in delta-receptor-mediated inhibitory mechanisms at cholinergic synapses in bladder ganglia.
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PMID:Enkephalinergic inhibition in parasympathetic ganglia of the urinary bladder of the cat. 260 Aug 44

Single-unit extracellular recording was carried out in rats to characterize the effects of dynorphin and several structurally related peptides on hippocampal pyramidal cell activity. Dynorphin, applied electrophoretically or by pneumatic pressure, produced a dose-dependent depression of both spontaneous and glutamate-evoked discharge in a majority (63%) of CA1 and CA3 cells tested. In addition, a small number of cells in both cellular fields responded to the peptide with a prolonged elevation in firing. The inhibitory effects of dynorphin were not blocked by naloxone. Moreover, administration of des-tyrosine-dynorphin depressed the firing of pyramidal cells in a manner similar to that of the parent compound. Ethylketocyclazocine produced a mixed pattern of excitatory and inhibitory effects, whereas naloxone-sensitive elevations in firing were most often observed with the application of dynorphin-(1-8). Application of [Leu5]enkephalin produced only facilitations in pyramidal cell firing. The possibility is raised that biologically significant non-opiate actions, in addition to potent opiate-mediated effects, may occur upon release of pro-dynorphin peptides in the hippocampus.
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PMID:Electrophysiological effects of dynorphin peptides on hippocampal pyramidal cells in rat. 285 95

An observational analysis of the effects of four kappa-opioid agonists on forward locomotion, rearing and grooming displayed by rats in a novel open field was undertaken. The doses of agonists used corresponded to those previously found to produce changes in food consumption. Ethylketocyclazocine (0.1 and 1 mg/kg), bremazocine (0.01 and 0.1 mg/kg) and tifluadom (0.3 and 3 mg/kg) exerted suppressant effects on all the activities monitored. Grooming behaviour appeared to be particularly sensitive to this action, being virtually abolished by the larger doses of these compounds. In contrast, the selective kappa agonist U-50,488H (0.1-3 mg/kg) only attenuated grooming at the two highest doses tested (1 and 3 mg/kg). None of the agonists tested produced stimulation of open field activity during the 1-h study. Reductions in activity occurred at doses previously found to increase and decrease food intake. It was therefore concluded that the hyperphagia induced by kappa agonists was not part of a more general behavioural activation, whilst reductions in food consumption probably result from a non-specific behavioural depression.
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PMID:Observational analysis of the effects of kappa opioid agonists an open field behaviour in the rat. 289 84

Excitatory junction potentials (e.j.p.s) evoked by nerve stimulation were recorded from muscle cells of the rabbit isolated mesenteric artery. At 0.03 Hz the e.j.p. amplitudes were stable. When a train of fifteen pulses was applied at 0.25 Hz or at higher frequencies (0.5, 1 and 2 Hz), e.j.p.s showed an initial facilitation followed by depression. [Met5]enkephalin 0.1 and 1 mumol/l, [D-Ala2,D-Leu5]enkephalin 0.1 and 1, but not 0.01 mumol/l, and [D-Pen2, L-Pen5]enkephalin 3 mumol/l all depressed the e.j.p.s evoked by trains of fifteen pulses at 1 Hz. When more than one concentration was used ([Met5]enkephalin, [D-Ala2,D-Leu5]enkephalin), the inhibition was concentration dependent. It was always greater for the first few e.j.p.s than for the later ones in a train. [Met5]enkephalin 1 mumol/l reduced the first e.j.p. at 1 Hz and the e.j.p.s evoked by 0.03 Hz to a similar extent. The inhibitory effect of [Met5]enkephalin 1 mumol/l on e.j.p.s persisted in the presence of yohimbine 0.3 mumol/l. Naloxone 1 mumol/l did not interfere with the effect of [Met5]enkephalin 1 mumol/l. Naloxone 10 mumol/l depressed some e.j.p.s and prevented the inhibition by [Met5]enkephalin 1 mumol/l. Neither ICI 154129 10 mumol/l nor ICI 174864 0.3 mumol/l had any effect of their own and both compounds antagonized the action of [Met5]enkephalin 1 mumol/l. Normorphine 10 mumol/l, fentanyl 1 mumol/l, ethylketocyclazocine 0.1 mumol/l, and dynorphin A(1-13) 1 mumol/l were all ineffective. Ethylketocyclazocine 1 mumol/l did not change the e.j.p.s either, but antagonized [Met5]enkephalin 1 mumol/l. [Met5]enkephalin 1 mumol/l failed to influence both the resting membrane potential of the muscle cells and the depolarizing effect of noradrenaline 3 and 30 mumol/l. We suggest that the axon terminals of post-ganglionic sympathetic neurones in the rabbit mesenteric artery possess opioid delta-, but not mu- or kappa-receptors. The activation of presynaptic delta-receptors inhibits the release of the neuroeffector transmitter. There is no evidence for any effect of co-released endogenous opioid peptides under our experimental conditions.
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PMID:Presynaptic opioid delta-receptors in the rabbit mesenteric artery. 303 Dec 83

The mechanisms for the biphasic response of unrestrained cats to centrally administered pentazocine were examined by injecting 1 mg pentazocine into the third cerebral ventricle at various ambient temperatures (TaS). The initial phase was hyperthermia at Ta = 34 degrees C, but at Ta = 22 degrees C hypothermia, which was enhanced at Ta = 0 degrees C, developed. The second phase was an increase in body temperature that occurred at all three TaS. No evidence was seen of compensatory thermoregulatory effector activity during development of either phase. The first phase can be attributed to general depression of thermoregulation whereas the second phase was likely due to an increase in the level about which body temperature was regulated. Ethylketocyclazocine (250-1000 micrograms) caused a very similar, dose-related change in temperature, neither phase of which, as reported previously for pentazocine, was reduced by a large dose of nalaxone. Thus both agonists appear to act on the same receptors to alter thermoregulation in the cat. These receptors are distinct from the naloxone-sensitive receptors stimulated by morphine.
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PMID:Effects of centrally administered pentazocine and ethylketocyclazocine on thermoregulation in the cat. 742 58