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Biomedical subjects

V N Zhukov

Publications and source records attributed to V N Zhukov.

At least 19 recordsLinked to original sources
PubMed1991

Dopaminergic involvement in the mediation of morphine effects on vocalization and movement reactivity in the rat.

To understand the role of dopamine in the mediation of opiate's analgesic and reinforcing activity, the influence of pharmacologically-induced increase (apomorphine in a high dose) and decrease (haloperidol and apomorphine in a low "presynaptic" dose) of dopamine neurotransmission on morphine-induced depression of vocalization and movement reactivity was investigated in freely behaving rats. Strong enhancement of morphine-induced vocalization reactivity depression and a weakening of movement reactivity depression typical to concomitant pharmacological increase of dopamine neurotransmission may represent the enhancement of its reinforcing and analgesic properties and inhibition of its depressive/sedative activity. Enhancement of MOR-induced depression of movement and vocalization reactivity characteristic of drug-induced decrease of dopamine neurotransmission may be the consequence of the blockade of opiate's reinforcing and stimulatory activity and summation of depressive/sedative actions typical to these drugs administered alone.

Animals↗
PubMed1991

[Pharmacological regulation of opioidergic antinociceptive mechanisms].

Naloxone-depending potentiation of morphine antinociception by some non-opioidergic compounds between different classes of drugs was found in experiments on mice using nociceptive stimuli of different modality. This potentiation can or cannot be bound with elevation of sensitivity of opioid receptors, release of endogenous opioids or destruction of blood-brain barrier function mor morphine peripheral administration. This potentiation named as "release of functional reserve of opioid antinociceptive response" can or cannot be accompanied by an increase of breathing function depression. Taking into account the data of literature about the dissociation of analgetic positive-supporting morphine effects and also the capability of some compounds to lower the narcogenic opiates potential, the supposition about the real possibility of creating combined drugs is made.

Animals↗
PubMed1991

[Effects of transcranial laser irradiation in near infrared range on antinociceptive reactions in mice after administration of diazepam, clopheline and morphine].

The experiments were carried out on white mice whose brain was irradiated transcranially with laser light in infrared range. Exposure to irradiation was 20 min. In one group of animals only laser light was used, in others laser was combined with morphine (3mg/kg), clonidine (0.5 mg/kg), and diazepam (1 mg/kg) injected intraperitoneally. The nociceptive reactions were studied with the help of "tail-flick" and "hot-plate" tests. It was found that laser light did not modify significantly the results of both tests. Moreover, it didn't influence the antinociceptive properties of morphine, clonidine and diazepam in the "hot-plate" test. In the "tail-flick" test laser light did not affect the action of clonidine, but provided naloxone-independent antinociceptive reaction with diazepam and increased the antinociceptive effect of morphine. Laser irradiation of the brain did not cause any significant morphological changes. These results suggest the possibility of modulating antinociceptive actions of morphine and diazepam by laser irradiation of the brain.

Animals↗
PubMed1988

Determinants of the analgesic action of opiates.

Nociceptive reactivity (tail-withdrawal reflex at 60 degrees C) during morphine administration was investigated in rats of the same population but of different batches in animals during restraint stress after their housing under different environmental conditions. The variability of the analgesic effects of opiates strongly depended on the functional state of animals at the moment of morphine administration, on the aversion to the living conditions prior to morphine and on some individual peculiarities of the organism with regard to the adaptive changes in opiate receptors. The direct action of naloxone, administered periodically, on opiate receptors induced an enhancement of the analgesic effects of morphine, which might result from the compensatory supersensitivity of opiate receptors after their blocking.

Analgesics, Opioid↗
PubMed1988

Hyperthermia and antinociceptive activity of thyrotropin-releasing hormone and morphine following central administration in rats.

This is an assessment of thyrotropin-releasing hormone (TRH) and morphine effects on nociceptive activity and temperature reaction in male Wistar rats following introduction of the substances into the periaqueductal gray matter or preoptic anterior hypothalamic nuclei via before hand cannulation. Morphine (10 micrograms) had marked antinociceptive activity, as shown by the tail flick-test, hot plate-test and mechanical pressure according to Randall-Selitto. TRH (5 micrograms) showed antinociceptive activity upon introduction into the periaqueductal gray matter, better expressed in the mechanical pressure test. Morphine (10 micrograms) and TRH (5 micrograms) gave rise to a hyperthermic reaction. The antinociceptive activity of morphine reduced upon preliminary administration of TRH, while its hyperthermic effect remained unchanged. These data are in support of the hypothesis that TRH may act as a functional opiate antagonist in the central nervous system.

Analgesics↗
PubMed1987

[Long-term enhancement of morphine hypalgesia as a result of periodic blockade of opiate receptors using naloxone].

A significant enhancement of the analgetic effect of morphine (6 mg/kg, subcutaneously; tail withdrawal reflex at 60 degrees C) was observed in rats 3-4 hours after single naloxone (1 mg/kg) administration. Periodical naloxone injection (0.5 mg/kg, subcutaneously, 3 times per day at 3.5-hour intervals for 3 days) led to a prominent and long-term (testing on the 20th and 105th hour after the last naloxone administration) enhancement of morphine analgesia (2.6 mg/kg subcutaneously) and insignificant inhibition of stress analgesia during two-hour immobilization of animals. These modifications of morphine and stress analgetic effects are considered a result of adaptive changes of opiate receptors after their blockade.

Analgesia↗
PubMed1987

[Angina of effort as an unfavorable prognostic factor].

A seven-year prospective study of a random 10% sample of a population of 50- to 59-year-old males from one municipal district in Moscow is reported. Mortality was reviewed among patients with complicated angina pectoris, i.e. those exhibiting other coronary symptoms as well, and among patients with uncomplicated angina as the primary and only sign of coronary heart disease (CHD). At long-term follow-up, the diagnosis of both varieties of angina is associated with aggravated vital prognosis. Some correlations between CHD risk factors and mortality are presented for both groups of anginal patients.

Aged↗
PubMed1987

[Possible role of positive reinforcement zones in the mechanisms of pain regulation and their relation to the endogenous opiate system].

The consequences of self-stimulation reaction (RSS) to pain threshold in tail withdrawal test (55 degrees C) and naloxone effect have been investigated in tests, using male rats with chronically implanted electrodes into the hypothalamus (AP = 1.5, L = 1.5, H = 8.5) and suture dorsal nucleus (AP = 7.0, L = 0, H = 7.0) (coordinates according to Fifková atlas). It was established that right after RSS, pain threshold in both zones increased 2-2.5-fold and 30 min later reached the initial level. Naloxone injected before RSS increased pain thresholds and decreased RSS frequency from hypothalamus but failed to change these RSS parameters from suture dorsal nucleus. However, naloxone did not affect the increase in pain thresholds caused by RSS from both zones. Taking into account the fact that analgesia appearing after RSS from the anterior hypothalamus as well as from suture dorsal nucleus is not reversed by naloxone, it is suggested that positive reward zones activation partially realized by opioidergic mechanisms or having no connection with them may lead to the development of non-opiate type analgesia.

Animals↗
PubMed1987

[Individual differences in the levels of pain sensitivity and analgesic effect of morphine in noninbred mice].

The initial threshold of pain sensitivity and the degree of morphine analgesia (12, 12, 70 mg/kg, i. p.) were assessed during mechanical, thermal and electrical stimulation, respectively, in noninbred white male mice. Two tests were performed, the second a week after the first one. A slight positive correlation (r = +0.39) between the initial threshold of pain reaction and the analgetic effect of morphine was found only during electrical stimulation in the first test, and positive correlation between the first and the second test during electrical and mechanical stimulation (0.34 and 0.27, respectively) was determined. The degree of morphine analgesia in different animals during second testing could either increase or decrease. It is suggested that previous testing of morphine analgetic effect cannot predict the efficacy of analgesia during the second testing and that the initial threshold of pain sensitivity cannot serve as a reliable predictor of morphine analgesia level.

Animals↗
PubMed1987

[Effect of naloxone on hypoalgesia in rats exposed to prolonged immobilization stress].

Significant hypoalgesia (tail-flick reflex at 60 degrees C) was observed in rats during the whole period of 24-hour immobilization in cramped cages, as compared to food-and-water deprived and control animals. This hypoalgesia was not antagonized by naloxone (1 mg/kg), however, the animals periodically receiving the drug during immobilization revealed aggressiveness and significant hypoalgesia after immobilization was discontinued (30-120 min observation).

Animals↗
PubMed1985

[Effect of the destruction of the brain serotoninergic system on the alcohol consumption by rats in the early periods of experimental alcoholism].

Albino noninbred rats were divided into groups, according to the duration of alcoholic anesthesia (4.5 g/kg i.p.), of predisposed (195.6 min) and non-predisposed (69.1 min) to voluntary intake of alcohol. Another group included animals screened for 21 days according to the level of intake of 15% ethanol under the conditions of free choice between alcohol and water (6.15 and 2.62 g/kg pure ethanol per day, respectively). The animals were subjected to electro-coagulation of the dorsal or magnus raphe nucleus or were injected with 5,6-dihydroxytryptamine--DNT (75 micrograms/microliters) into the ventricles of the brain. It was established that in rats non-predisposed to alcohol intake, the destruction of the raphe nuclei, of the dorsal in particular, or injection of DOT to animals with a weak alcoholic motivation produces a dramatic increase in alcohol intake. In alcohol intake predisposed rats and in animals with a high level of alcohol use, analogous exposures do not bring about any significant differences in alcohol intake. The data obtained indicate that the reduced serotonin content in the brain is associated with an increase in the level of alcoholic motivation.

5,6-Dihydroxytryptamine↗
PubMed1982

[Serotonin content in different sections of the brain, liver, intestines and blood of rats predisposed and not predisposed to alcohol consumption].

Experiments were made with white random-bred rats (males) exposed to ethanol. The content of serotonin measured by spectrofluorometry was higher in the hypothalamus, brain stem and intestine, and was lower in the thalamus, striatum liver and blood in the animals predisposed to voluntary alcohol consumption and with lateral position duration 62 +/- 18 min as compared with the animals not predisposed to alcohol consumption and with lateral position duration 196 +/- 23 min, the dose of ethanol being 4.5 g/kg i. p. Thirty minutes after ethanol administration in a dose of 2.5 g/kg i. p. to the alcohol-predisposed rats there was a lowering of the serotonin content in the hypothalamus and an increase in the thalamus, brain stem, liver and blood. Meanwhile in the rats not predisposed to alcohol consumption, the serotonin content rose in the hypothalamus, brain stem, liver, intestine and blood and fell in the thalamus and striatum. It is assumed that the serotoninergic system of the brain may play a role in the formation of "positive" or "negative" attitudes to ethanol in the population of white random-bred rats.

Alcoholism↗
PubMed1982

[Assessment of ischemic heart disease risk factors in relation to mortality (data from a multiyear prospective study in Moscow)].

Seven-year prospective study of mortality among the selected male population born in 1909--1918 showed that in some cases the region of high death risk is noted not only in the upper but also in the lower decyls and that of low risk in the center of the distribution of some of the ischemic heart disease (IHD) risk factors. Differentiation of the whole population into groups of individuals with IHD and those without IHD according to the findings of the initial examination enabled the authors to distinguish various tendencies of changes in the death risk depending on the arterial pressure levels and the lipid content. In prolongation of the period of observation of the population it is necessary to take into consideration the variability of the risk factors as well as the development of new cases with IHD in the period after the first examination.

Blood Glucose↗
PubMed1982

[New cases of ischemic heart disease and the dynamics of its various forms in a multiyear prospective study of men 50-59 years old].

A report of a follow up study on a selected male population aged 50-59 from one of the central districts of Moscow is presented. The initial check-up found ischaemic heart disease (IHD) in 18.4% of cases, and 61/2 years later in 27.7% (p less than 0.01). The frequency of new cases of IHD appearing was 17.6%, in older age group (55-59) it was 2.8% higher, than in the younger group (50-54). In the older male group during the observation period death rate from IHD was encountered more frequently (6.1%), than in the younger group (1.6%). The number of new cases of myocardial infarction found during the second investigation, and deaths from acute coronary insufficiency in both age groups was practically the same: 8.2% among the total population. General number of new cases of IHD in 61/2 years, determined with mortality from IHD was 18.4%, or 2.8% per year. The stability of the more severe manifestations of IHD is shown. It is noted that atypical forms of angina pectoris and "doubtful" ischaemic changes on ECG may be regarded as "precursors" of IHD and persons with such signs require further follow up.

Angina Pectoris↗