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

Field trials were carried out during 1982-86 in two different ecotypes in central Zambia to determine the impact of tick control on the liveweight gain (LWG) of cattle. During the first 2 years of the trial a diamidide acaricide (Amitraz) sprayed at weekly intervals caused periodic depression in LWG in young animals. Thereafter a pyrethroid acaricide (cypermethrin) was used. During the 1984-85 tick season infestations of 50-120 adult Amblyomma variegatum Fabricius in untreated animals caused significant reductions in LWG. From the differences in LWG between treated and untreated cattle, the induced loss in LWG was estimated at 46-61 g per engorged female A.variegatum.
 ...
PMID:Effect of tick control on liveweight gain of cattle in central Zambia. 251 78

1. The force of the electrically driven rat right ventricle strip is increased by isoprenaline but not by procaterol, a beta 2-adrenoceptor agonist. The effects of some beta-adrenoreceptor antagonists on the responses of the strip to isoprenaline have been determined. 2. Metoprolol (a beta 1-adrenoreceptor-selective antagonist) at 3 x 10(-8)-3 x 10(-7) moll-1 and ICI 118,551 (a potent beta 2-adrenoreceptor-selective antagonist) at 10(-7)-10(-6) moll-1 had no effect on maximum responses to isoprenaline and caused parallel rightward shifts of the isoprenaline response curves. The pA2 values for metoprolol and ICI 118,551 were 7.86 and 7.40, respectively. Thus the isoprenaline responses of the rat right ventricle strip are due to stimulation of beta 1-adrenoreceptors. 3. Metoprolol at 10(-6) moll-1 acted as a dual antagonist of the responses of the ventricle strip to isoprenaline causing parallel rightward shifts of the concentration-response curves which was due to beta 1-adrenoreceptor antagonism and a depression of the maximum response to isoprenaline which was probably due to membrane stabilizing activity. 4. Low concentrations of (+/-)-pindolol (10(-8) moll-1), (+)-pindolol (10(-7) moll-1), (-)-pindolol (10(-8) moll-1) and mepindolol (10(-10) moll-1) had no effect on isoprenaline maximum responses and caused parallel rightward shifts of isoprenaline response curves. Both (+/-)- and (-)-pindolol at 10(-7) moll-1, mepindolol at 10(-9)-10(-7) moll-1 and bopindolol at 10(-9)-10(-7) moll-1 reduced the isoprenaline maximum responses and caused non-parallel rightward shifts of the isoprenaline response curves. 5. BAAM (an irreversible beta-adrenoreceptor antagonist) treatment (3 x 10(-6) moll-1) for 30 min followed by 60 min washout reduced the isoprenaline maximum responses and caused a non-parallel rightward shift of the isoprenaline response curve. The kA (dissociation constant) for isoprenaline was 1.10 x 10(-6) moll-1. Calculation of receptor occupancy demonstrated that in order to produce a maximal response of the rat right ventricle strip, isoprenaline had to occupy 73% of the beta 1-adrenoreceptors. 6. The use of the rat right ventricle strip, a tissue with a small beta 1-adrenoreceptor reserve for isoprenaline, allows a definitive characterization of reversible (e.g. metoprolol) and irreversible (e.g. BAAM) beta 1-adrenoreceptor antagonists. It is suggested that (+/-)- and (-)-pindolol, mepindolol and bopindolol may be slowly dissociating beta 1-adrenoreceptor antagonists.
 ...
PMID:The effects of beta-adrenoreceptor antagonists on the force responses of the electrically driven rat right ventricle strip to isoprenaline. 257 75

Intravenous amitraz caused significant hypotension and bradycardia in pentobarbitone anaesthetized guinea-pigs. Depression of blood pressure reached a plateau with a dose of 10 mg/kg but heart rate continued to fall in a dose-dependent manner, up to a fall of 90 beats per minute after a total of 160 mg/kg/min. Amitraz was then tested on spontaneously beating guinea-pig isolated atria. The maximum bath concentration approximated a blood concentration produced by 5 mg/kg amitraz in the guinea-pig (2.3 X 10(-4) M). Amitraz did not significantly shift the dose-response curve to isoprenaline or acetylcholine but antagonized histamine rate responses competitively in the presence of propranolol (2 X 10(-6) M). Propranolol unmasked a dose-dependent depressant effect of amitraz on atrial rate, an effect abolished with atropine (1 X 10(-5) M). Amitraz increased atrial force of contraction, an effect which was not seen when propranolol was present in the bath solution. Amitraz also depressed atrial rate directly, but this effect was minor in comparison to bradycardia seen in the guinea-pig. It is likely that the cardiovascular depression seen in the guinea-pig following amitraz i.v. is caused by an alteration in autonomic drive rather than a significant direct cardiac effect.
 ...
PMID:The cardiac effects of amitraz in the guinea-pig in vivo and in vitro. 287 7

Amitraz is a formamidine compound used as a topical acaricide mainly in dogs and cattle. In an initial attempt to explain some of its side-effects, the actions of amitraz were studied on the cardiovascular and respiratory systems in thiopentone/methoxyflurane-anaesthetized dogs. In separate experiments, amitraz, at doses of 1, 2 and 5 mg/kg i.v., dissolved in DMSO, increased blood pressure for 1 hour. Heart rate decreased initially then showed a dose-related return towards control values. Tidal volume, respiratory rate and respiratory minute volume all showed initial transient depression. Hyperventilation was a feature after high doses of amitraz. Cumulative doses of amitraz of 0.5, 1, 2, 5 and 10 mg/kg i.v., at intervals of 5 min, increased blood pressure. Heart rate decreased at lower doses but increased slightly after higher doses. Five minutes after injection, cardiac index had returned to control values while total peripheral resistance showed a dose-related increase. The mechanism of action of amitraz in dogs cannot be determined from these results; however, other reports have described an alpha 2-adrenoceptor agonist action of this formamidine compound.
 ...
PMID:Cardiovascular and respiratory effects of the acaricide amitraz. 361 41

Many pesticides are formulated in organic solvents. An example is amitraz, one of the formamidine group of pesticidal chemicals. As a contingency against the possibility of poisoning cases occurring, the toxicity and pharmacology of amitraz were reviewed in order to recommend medical management procedures. Amitraz has pharmacological activity, including monoamine oxidase inhibition, alpha-adrenergic agonist activity and it inhibits prostaglandin synthesis. Extrapolating from acute studies in animals, the likely signs of poisoning in humans may include bradycardia, hypotension, hyperglycaemia, CNS depression, and hypothermia. Despite the presence of amitraz, it appears that the xylene is the more aggressive component in the formulation tested, and treatment for over-exposure by the oral route is generally as for xylene ingestion, but the presence of amitraz is an indication for gastric lavage. Few cases of poisoning have occurred and these are presented.
 ...
PMID:Extrapolation from safety data to management of poisoning with reference to amitraz (a formamidine pesticide) and xylene. 664 15

Amitraz poisoning is a rare disorder characterised by central nervous system and respiratory depression, bradycardia, hypotension, hypothermia, hyperglycemia, vomiting, convulsion and glycosuria. In this study, eight pediatric patients with amitraz poisoning were presented. This study revealed that clinical manifestations of poisoning by oral and dermal route emerged within 30-120 min and that central nervous system depression which is the most important sign resolved with 8-18 h and others 36-48 h. All cases were discharged as recovered after 48 h. To our knowledge only six cases have been reported in the literature. Because of the limited information in the literature, the cases were reported.
 ...
PMID:Amitraz poisoning in children: clinical and laboratory findings of eight cases. 942 71

Three-mo-old male Wistar rats were sprayed with 250, 500, 1000 and 2000 ppm amitraz 2 w apart or given single doses of 50, 100, or 250 mg/kg p.o, i.m. or i.p. No effects were observed in the amitraz-sprayed rats. Single doses of amitraz p.o, i.m. or i.p. was non-toxic at 50 mg/kg, toxic at 100 mg/kg and lethal at 250 mg/kg within 24 h of dosing. Survivors were killed 48 h post-dosing. Features of toxicity were depression, incoordination of movement, paresis of the limbs, hepatonephrotoxicity, muscular hemorrhage at site of injection and peritonitis following i.p. injection. These changes, accompanied by leucopenia, were correlated with alterations in serum AST and concentrations of serum constituents. Amitraz did not inhibit serum ChE activity.
 ...
PMID:Effects of amitraz given by different routes on rats. 1059 39

Amitraz is an acaricide and insecticide indicated for the treatment of generalized demodicosis in dogs and for the control of ticks and mites in cattle and sheep. There is little information available in the human literature about the toxicology of the product. In this study, the clinical and laboratory features of amitraz poisoning in 11 children are presented. The age range of the patients was 2-1/2 to 6 years. Accidental ingestion of an improperly stored liquid pesticide was determined in all patients. Unconsciousness (100%), drowsiness (100%), and myosis (84%) were the most common abnormal signs; 45%, 27%, and 18% of patients had bradycardia, respiratory insufficiency, and hypotension, respectively. All of the patients were treated with atropine, gastric lavage, activated charcoal, and supportive care. Although the patients had a prompt response to therapy, three patients required multiple doses of atropine during a 24-h period. This study revealed that clinical poisoning by oral route emerged within 30-90 min and that central nervous system (CNS) depression, which is the most important sign, resolved within 8-1/2-14 h. All cases were discharged.
 ...
PMID:Amitraz poisoning in children. 1112 12

Amitraz, an insecticide and veterinary medicine, has been available in many countries since 1974 but reports of poisoning with it have only become prominent in the last 7 years. The vast majority of cases have occurred in Turkey and have involved children. The data available, both human and animal, do not allow clear separation of the features of toxicity of amitraz from those of the hydrocarbon solvents in which it is commonly dissolved. Amitraz stimulates alpha 2-adrenoceptors resulting in impairment of consciousness, respiratory depression, convulsions, bradycardia, hypotension, hypothermia and hypoglycaemia. Even the most severely poisoned patients recover with nothing more than intensive care; only one possible death has been documented. Animal studies indicate that the alpha 2-adrenoceptor antagonists, yohimbine and atipamezole, can reverse amitraz-induced toxicity but they have not been assessed in poisoned humans.
 ...
PMID:Poisoning with amitraz. 1507 16

Amitraz is an insecticide/acaricide of formamidine pesticides used worldwide to control ectoparasites in animals. Amitraz poisoning is a rare disorder characterized by central nervous system (CNS) and respiratory depression, bradycardia, hypotension, hypothermia, hyperglycemia,nausea and vomiting. Poisoning may occur either by oral inhalation and dermal route. In this study, we present seven pediatric patients with amitraz poisoning. The initial symptoms were unconsciousness, dizziness and vomiting; and emerged within 30-150 minutes. The length of stay in the intensive care unit (ICU) was between 18-62 hours.
 ...
PMID:Amitraz poisoning: clinical and laboratory findings. 1518 Dec 99


1 2 Next >>