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)

The mechanism of anti-nicotinic actions of hexamethonium, mecamylamine and adenosine was investigated in guinea pig isolated ileum. Mecamylamine shifted the dose-response curves for nicotine to the right with a gradual depression. On the other hand, hexamethonium shifted the curves to the right without a depression and adenosine made only a gradual depression, suggesting the different modes of their antinicotinic actions. The transmurally-stimulated twitch response was unaffected, partially inhibited and abolis hed by hexamethonium, mecamylamine and adenosine, respectively. These three compounds also had little effect on direct muscle response to acetylcholine and on the acetylcholinesterase activity of the ileum. From these results, it is suggested that the antagonism to the effect of nicotine shown by mecamylamine does not appear to be a simple competitive blockade of ganglionic receptors as is the case with hexamethonium and that adenosine may antagonize the effect of nicotine non-competitively. The mechanism by which mecamylamine and adenosine showed anti-nicotinic action is discussed.
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PMID:Comparative studies on anti-nicotinic action of hexamethonium, mecamylamine and adenosine in the guinea pig isolated ileum. 59 56

Acute toxicity studies in 24 newborn calves and 12 two-year-old steers were conducted with a microencapsulated formulation of diazinon (O-O-diethyl O-(2-isopropyl-6-methyl-4-yrimidinyl) phosphorioate) after dermal applications. For calves, the maximum safe dosages of a diazinon wettable powder formulation were identical with those of the new formulation (0.05% concentration); for older cattle, safe dosages were 0.25% concentration. Thus, because of the slow release and absorption of diazinon, the safety factor for mature cattle is fourfold. In the present study, there was cholinesterase depression in calves at the toxic concentrations of 0.1% and in steers at concentrations of 2.0%. As determined by the mean cholinesterase depression activity, the dose-response relationship was true in the 4 treatment groups of older cattle, but was erratic in the 6 groups of calves. The use of modified and improved insecticidal formulations, such as the encapsulated type, is recommended. Their use may prolong acaracidal activity due to effective residues, eliminate the need for repeated applications at shorter intervals of time, and possibly allow increased dosages to mature cattle, without toxicity, and thus reduce acquired resistance of ticks and other insects.
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PMID:Toxicologic evaluation of microencapsulated formulation of diazinon applied dermally to cattle. 67 43

Acetyl- and butyryl-cholinesterase activities have been measured biochemically in normal brain tissue, in senile dementia of Alzheimer type and in mental disorders without Alzheimer-type abnormalities. Acetylcholinesterase was significantly reduced and butyrylcholinesterase significantly increased, compared with the normal, in the hippocampus and temporal cortex of the Alzheimer cases. No significant enzyme changes were seen in the other diseases investigated including multi-infarct dementia, schizophrenia and depression. There was no correlation between age and acetylcholinesterase activity, but a significant positive correlation between the butyrylcholinesterase activities with increasing age (60-90 years) was found in the hippocampus. The possible connection between cholinergic system pathology and these cholinesterase abnormalities in Alzheimer dementia is discussed.
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PMID:Changes in brain cholinesterases in senile dementia of Alzheimer type. 70 27

Necropsy brain tissue from normal (control) patients and patients with depression and dementia was examined for activities of various cholinergic components, and these related to the degree of senile plaque formation and extent of intellectual impairment. Choline acetyltransferase and acetylcholinesterase activities decreased significantly as the mean plaque count rose, and in depressed and demented subjects the reduction in choline acetyltransferase activity correlated with the extent of intellectual impairment as measured by a memory information test; muscarinic cholinergic receptor binding activity remained unchanged with increasing senile plaque formation but butyrylcholinesterase activity increased. The results suggest a close relation between changes in the cholinergic system and Alzheimer's dementia, but the precise role of the system in this disease remains to be elucidated.
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PMID:Correlation of cholinergic abnormalities with senile plaques and mental test scores in senile dementia. 71 62

During the last 4 years, 225 patients have been referred to the Danish Cholinesterase Research Unit following an episode of prolonged apnoea after suxamethonium. Fourteen patients (6.2%) were found to have a low serum cholinesterase activity due to an acquired deficiency (for instance, liver disease, chronic debilitating disease or carcinoma). One hundred and forty-eight patients (65.8%) had an inherited abnormal serum cholinesterase, and 105 of these patients (46.7%) were homozygous for the atypical enzyme (E1 Ea1). The mean period of apnoea in this latter group was 92 min (range: 25--240). Seventeen patients (7.6%) were heterozygous for the normal and the atypical enzyme (Eu1 Ea1), with a mean apnoea period of 25 min (range: 7--60 min). Twelve patients were found to be heterozygous for the atypical and the silent gene (E(a)1 E(s)1). The mean period of apnoea was 126 min (range: 45--210 min). Fourteen patients had other rare genotypes. The longest mean period of apnoea (170 min, range: 70--330) was found in patients homozygous for the silent gene (Es1 Es1). The silent gene and the fluoride-resistant gene were found in 8.9% and 2.7% of the patients, respectively. In 63 patients (28.1%) both the type and quantity of serum cholinesterase were normal. In 34 of these patients (15.2%), the prolonged apnoea was due to other causes; for example, suxamethonium overdose, hyperventilation and central as well as peripheral respiratory depression. However, in the other 29 patients (12.9%), the reason for the prolonged apnoea could not be established. The possibility therefore exists that these cases represent unknown genotypes.
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PMID:Prolonged apnoea after suxamethonium: an analysis of the first 225 cases reported to the Danish Cholinesterase Research Unit. 72 55

Increasingly widespread application of organophosphate pesticies has underscored the importance of studying their effects on human behavior. Clinical reports and laboratory investigations have generally supported the assumption that neurobehavioral manifestations of organophosphate toxicity are attributable to accumulation of acetylcholine at central and peripheral synapses as a result of cholinesterase inhibition. Despite methodologic shortcomings in many of the published studies, investigators generally agree on the presence of several behavioral sequelae of organophosphate poisoning: (a) impaired vigilance and reduced concentration, (b) slowing of information processing and psychomotor speed, (c) memory deficit, (d) linguistic disturbance, (e) depression, and (f) anxiety and irritability. The few studies of asymptomatic workers at risk for repeated exposure to organophosphate pesticides have produced only equivocal findings concerning the presence of less severe or latent forms of these behavioral abnormalities.
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PMID:Behavioral effects of organophosphate in man. 78 76

A field trial was set up to test the prophylactic properties of the organophosphorous drug metrifonate (Bilarcil Bayer AG). Subjects were rural African children living in an area of Rhodesia where Schistosoma haematobium and S. mansoni are highly endemic. The trial was conducted in three stages, a preliminary period of therapy followed by two six-month periods of prophylaxis. Parasitological and haematological tests were carried out monthly and major assessments (including clinical examinations) were carried out prior to the start of the trial and at the end of each of the three stages. Drug was given to the appropriate groups at a dose rate of 7-5 mg/kg once per fortnight for three doses during the therapy stage and four-weekly during the prophylaxis stage. Results with S. haematobium were very good. A 60% cure-rate was observed six weeks aection was obtained in those children continuing to receive the drug as a prophylactic, even during the season of highest transmission; intensities of infection in those who became infected were very low. Infection rates in the treated but unprotected group rose steadily from 40% at week 11 to 95% at week 70. There was a sigificant effect upon the intensity of S. mansoni infections only when pre- and post-trial data were compared. Apart from the anticipated (and previously reported) depression of plasma cholinesterase values no side effects were recorded. Drug tolerance and acceptibility were very high. It is likely that the costs of a year's protection against S. Haematobium using metrifonate will be significantly lower than protection by molluscicidal techniques or single courses of treatment with established drugs.
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PMID:Field trial of metrifonate in the treatment and prevention of schistosomiasis infection in man. 84 20

Clinical signs, pathologic changes and biochemical changes occurred in cattle with natural and experimental triaryl phosphate poisoning. Natural poisoning was caused by triaryl phosphates escaping from a gas pipeline compressor station. The clinical signs were posterior motor paralysis, dyspnea, diarrhea and agalactia. Experimental doses of 1/2-1 gm/kg body weight of these organophosphate compounds caused depression of cholinesterase and axonal degeneration in the spinal cord.
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PMID:Triaryl phosphate poisoning in cattle. 85 97

To acquire information regarding the potential hazard of pesticide-impregnated collars to dogs, 13 male Beagles were allotted to 2 groups; 8 of the dogs were fitted wtih propoxur-impregnated tick and flea collars and the other 5 were fitted with placebo collars. All dogs wore their collars for 42 consecutive days. The dogs wearing test collars had significant (P less than 0.01) depression of erythrocyte and plasma cholinesterase activities at day 1 after collar application; however, the enzyme activity values returned to the preexposure range within 3 days. Miosis, with decreased pupillary response, was noticed during the 1st week of exposure. Irritation of the skin of the neck was mild and transient in both the test and control groups from the 2nd week onward.
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PMID:Evaluation of a carbamate-impregnated flea and tick collar for dogs. 89 10

The effects of oral prednisone on plasma and red blood cell cholinesterases have been studied in human volunteers. While the activity of plasma pseudocholinesterase is depressed by glucocorticoid administration, the activity of red blood cell true cholinesterase is not affected. Cortisol administration to rats, intraperitoneal or subcutaneous, inhibited liver pseudocholinesterase activity, indicating a possible depression of the enzyme protein synthesis.
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PMID:Effect of glucocorticoids on liver and blood cholinesterases. 92 92


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