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)

This study examined the relationship between inhibition of cholinesterase activity (CA) and thermoregulatory response in the rat following exposure to the organophosphate (OP), diisopropyl fluorophosphate (DFP). Male Long-Evans rats were injected with DFP dissolved in peanut oil in doses ranging from 0 to 1.5 mg/kg (s.c.). Colonic (Tcol) and tail skin temperature (Ttail) were recorded at 0, 1, 2 and 3 h post-injection. At 3 h post-injection the rat was sacrificed and a blood sample was taken by cardiac puncture and analyzed for CA. There was a biphasic dose effect of DFP on Tcol with slight but significant elevation in Tcol in the dose range of 0.01-0.5 mg/kg and a significant depression in Tcol at doses of 1.0 and 1.5 mg/kg. There was a dose-dependent fall in CA with DFP administration in the erythrocyte, plasma, and whole blood fractions. Hypothermia was associated with 80-87% inhibition in CA, whereas the elevation in Tcol was associated with 20-70% inhibition in CA. DFP also elicited significant elevations in Ttail. Overall, the data fail to demonstrate any clear relationship between inhibition of blood CA and thermoregulatory response following exposure to DFP. However, the elevation in Tcol following relatively low doses of DFP may be of relevance to the frequently reported symptom of fever in humans exposed to OP agents.
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PMID:Relationship between cholinesterase inhibition and thermoregulation following exposure to diisopropyl fluorophosphate in the rat. 175 22

1. Azapirones, selective partial agonists at the 5-HT1A receptor subtype, induce hypothermia and corticotropin (ACTH)/cortisol release as specific functional correlates of central 5-HT1A receptor activation. 2. Compared to controls, hypothermic and ACTH/cortisol responses to the azapirone ipsapirone are attenuated in patients with unipolar depression and panic disorder but not in patients with obsessive-compulsive disorder. The impaired thermic and neuroendocrine responses are associated with increased basal cortisol secretion in depressed patients but not in patients with panic disorder. 3. Chronic treatment with the selective 5-HT reuptake inhibitor fluoxetine decreases 5-HT1A receptor-mediated responses in patients with obsessive-compulsive disorder, while long-term treatment with the tricyclic antidepressant amitriptyline further decreases hypothermia following ipsapirone but has no effect on ACTH/cortisol release. 4. Alteration of the 5-HT1A receptor and/or its signal transduction pathways may play a role in the pathophysiology and treatment of anxiety disorders and depression.
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PMID:5-HT1A receptor responsivity in anxiety disorders and depression. 176 90

In experiments on 123 male rats have been found that the combination of immobilizing and cold (4 degrees C) stresses during 6 hours results in the formation of 4.5 gastric mucosa ulcers in every rat, marked activation of lipoperoxidation and depression of antioxidant activity of myocardium, significant increase of relative mass of adrenal glands, decrease of spleen mass and death of 80% animals accompanied by the reduction of concentration of thyroid hormones in blood serum and hypothermia (to 28 degrees C). The prestress injection of small doses of thyroidine decreased of mucosa defect rate and the number of ulcers to 2.8, made less marked the changes of relative mass of adrenal glands and spleen and the changes of concentration of thyroid hormones in blood serum, significantly limited the activation of lipoperoxidation, depression of power in antioxidant systems of myocardium, hypothermia (to 32.5 degrees C) and significantly increased the survival rate (to 70%).
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PMID:[The enhancement of body resistance to combined exposure to immobilization and cold with thyroid hormones]. 176 34

Urethane-anesthetized rats were used to study the mechanism of cocaine-induced death. Continuous recording of the changes in five physiological parameters, including respiratory rate (RR), electroencephalogram (EEG), blood pressure (BP), electrocardiogram (ECG), and body temperature (BT), were conducted after intraperitoneal (IP) administration of a single dose of cocaine HCl (70 mg/kg). In the control group (normothermic with core body temperature 37.7 +/- 0.1 degree C and spontaneously breathing), the death rate was 88% (15/17), and the average time to respiratory arrest was 12.99 +/- 1.40 min (mean +/- SEM). The first set of experiments investigated the contribution of hypothermia to cocaine-induced death. The hypothermic group (core body temperature 33.9 +/- 0.3 degrees C and spontaneously breathing) had a death rate of 81.5% (22/27), and an average time to respiratory arrest of 16.70 +/- 1.24 min, which was significantly (p les than 0.05) prolonged. A substantial decrease in respiratory rate was seen in normothermic group, while all the other measured parameters remained relatively stable until respiratory arrest. Sequential arterial blood gas data in this group showed a decrease in PaO2 from 116.0 +/- 5.7 mmHg to 57.7 +/- 4.6 mmHg, an increase in PaCO2 from 27.7 +/- 2.2 mmHg to 42.7 +/- 3.0 mmHg, and a decrease in pH from 7.467 +/- 0.039 to 7.357 +/- 0.003. To confirm that respiratory depression was an important mechanism of cocaine-induced death in this model, ten normothermic rats underwent mechanical ventilation, and all survived cocaine exposure. This study points to the important role of respiratory depression as a cause of cocaine-induced death.
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PMID:Cocaine-induced respiratory depression in urethane-anesthetized rats: a possible mechanism of cocaine-induced death. 178 91

The reaction of cells with micronuclei in respect of the induction of specific dicentric chromosomes with halogenated analogs of thymidine at various temperatures was studied. The positive correlation between the temperature and frequency of dicentrics was shown for all halogenated analogs of thymidine. The minimum frequency of dicentrics was found in the case when used 5-iododeoxyuridine and hypothermia (34 degrees C). The using of 5-bromodeoxyuridine at different temperatures displayed the intermediate results. The maximum level of dicentrics discovered under action of 5-chlorodeoxyuridine and hyperthermia (40 degrees C). In the former case the depression of mitotic chromosome condensation of micronuclei registered, in the latter one the chromosomes with portions of delayed spiralization were not found.
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PMID:[Telomeric chromosome fusion in cells with micronuclei under the combined action of hyperthermia and hypothermia and halogenated analogs of thymidine]. 179 64

The toxicity of Z-103 (catena-(S)-[mu-[N alpha-(3-aminopropionyl) histidinato(2-)-N1,N2,O:N tau]-zinc], CAS 107667-60-7) was evaluated in mice and rats after single administration. LD50 values in mice were 1269 mg/kg for males and 1331 mg/kg for females by the oral route, 220 mg/kg for males and 165 mg/kg for females by the intraperitoneal route, and 758 mg/kg for males and 874 mg/kg for females by the subcutaneous route. LD50 values in rats were 8441 mg/kg for males and 7375 mg/kg for females by the oral route, 405 mg/kg for males and 422 mg/kg for females by the intraperitoneal route and more than 5000 mg/kg for both sexes by the subcutaneous route. No sex differences were observed. A decrease in locomotor activity, ventral posture, crouching, hypothermia and respiratory depression were observed in both mice and rats as the main clinical signs. In addition to these changes, induration, swelling and crust formation were observed at the subcutaneous injection site.
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PMID:Single dose toxicity study on catena-(S)-[mu-[N alpha-(3-aminopropionyl) histidinato(2-)-N1,N2,O:N tau]-zinc] in mice and rats. 179 79

In order to minimize heat loss cold stress induces peripheral vasoconstriction via the sympathetic nervous system. This effect is most pronounced in the extremities. Vasoconstriction does not appear in the head-neck region--a fact of great importance in emergency situations. In order to compensate for heat loss shivering is an early event, where involuntary muscle contractions increase metabolic rate 2-6 fold. Early tachycardia and elevated blood-pressure, followed by progressive bradycardia and lowered pressure are common cardiovascular effects of hypothermia. Death due to ventricular fibrillation or asystole occurs between 28 degrees-25 degrees C. Cold stress causes an osmolal diuresis with sodium and chloride as the main constituents. The natriuresis is of tubular origin and could be due to impaired autoregulation in the kidney and/or depend on the natriuretic polypeptide. The augmented urine flow decreases blood volume, lowers physical working capacity and increases blood viscosity--all negative events in a hazardous situation. Sudden immersion initiates hyperventilation for 1-2 minutes with an increasing risk of drowning. Thereafter ventilation decreases to rates consistent with metabolic requirements. In severe hypothermia carbon dioxide retention causes respiratory and metabolic acidosis. Hypothermia induces progressive depression of mental functions starting with apathy and bizarre behaviour and ending in lethargy and coma often between 30 degrees-28 degrees C. The paradoxal feeling of heat with undressing in agony could depend on cerebral receptor disturbances.
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PMID:Human physiology under cold exposure. 181 74

The paradigm of long-term sleep deprivation was used as a model of chronic inescapable stress in rats. Several basic metabolic parameters (body weight changes, food and water intake, rectal temperature, serum glucose and creatinine), adrenal and thyroid secretion, norepinephrine and dopamine content and turnover in discrete brain regions, and open field behaviour were examined in the course of the exposure to experimental stress. Sleep deprivation over 7-9 days caused complete physical exhaustion of the animals. It was accompanied by hypothermia and hyperphagia. Adrenal activity was characterized by significant hypercorticism, but also by a relative decrease of the responsiveness to ACTH. A gradual decrease in the thyroid secretion was observed. Sleep deprivation elicited a depletion of norepinephrine in the hypothalamus and decreased its turnover, whereas hippocampal norepinephrine content decreased without considerable turnover alterations. Striatal dopamine content and turnover remained unaffected. Behavioural depression and altered open field activity were also observed in exhausted animals. Long-term sleep deprivation, therefore, seems to reproduce some of the biological correlates of the depressive illness, and may be useful in studying the development of coping failure as a result of chronic stress exposure.
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PMID:Neuroendocrine and neurochemical consequences of long-term sleep deprivation in rats: similarities to some features of depression. 181 84

The cold stress induced in rabbits by lowering their body temperature by 3 degrees C resulted in neutrophilia and a decrease in number of phagocytes and phagocytized bacteria. The stress did not affect the number of lymphocytes and the ability of forming E rosettes by T lymphocytes, but depressed the formation of EAC rosettes by B lymphocytes. This inhibition of neutrophil activity was antagonized completely by acetylsalicylic acid, and substantially by mefenamic acid and indomethacin administered, in doses inhibiting pyrogen-induced fever, either 2.5 h before or 1.5 h after the hypothermia. The drugs did not antagonize the depression of the ability of formation of EAC rosettes.
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PMID:Responses of neutrophils and lymphocytes in the cold stress: effects of nonsteroid anti-inflammatory drugs. 182 25

Few safe and effective anesthesia regimens have been described for use in rabbits, partially because of the susceptibility of this species to sometimes fatal respiratory depression. Although inhalant anesthetics are generally safer than injectable anesthetics, their use may be limited by lack of equipment or facilities. This study was conducted to compare effects of several injectable anesthetics in rabbits on response to noxious stimuli, heart rate, respiratory rate, and rectal temperature. Six injectable anesthetic combinations were administered to rabbits: xylazine-ethyl-(1-methyl-propyl) malonyl-thio-urea salt (EMTU), ketamine-EMTU, xylazine-pentobarbital, xylazine-acepromazine-ketamine (XAK), ketamine-chloral hydrate, and ketamine-xylazine. All combinations induced a depression of respiratory rate. Although rectal temperature values were reduced to some degree in each group, the most profound hypothermia was induced by XAK. The combination that induced the longest duration of anesthesia was XAK. It was concluded that XAK was preferable for longer periods of anesthesia (60 to 120 minutes), although it induces severe hypothermia. For short periods of anesthesia, xylazine-pentobarbital, xylazine-EMTU, or ketamine-xylazine were deemed adequate; however, xylazine-EMTU induced the best survivability and consistency.
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PMID:Comparison of several combinations for anesthesia in rabbits. 185 90


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