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Biomedical subjects

Z Kleinrok

Publications and source records attributed to Z Kleinrok.

At least 145 records · Page 8Linked to original sources
PubMed1992

Modification of antinociceptive action of morphine by Ukrain in rodents.

Morphine-induced (0.1 mg/kg s.c.)antinociceptive action was determined in rodents by using the writhing syndrome, hot plate and tail-flick tests. Ukrain given i.p. in doses equivalent to 0.05 and 0.1 LD50 did not affect the reactivity of the mice in the writhing syndrome test. Only in a dose of 0.1 LD50 did Ukrain produce an antinociceptive effect in the hot-plate and tail-flick tests. Ukrain significantly enhanced the antinociceptive effect of morphine in the hot-plate and tail-flick tests. The action of morphine was significantly suppressed by Ukrain in the writhing syndrome test in mice. These results indicated that Ukrain modified the antinociceptive action of morphine.

Acetates↗
PubMed1992

Effect of Ukrain on the efficacy of anti-epileptic drugs against maximal electroshock-induced seizures in mice.

It has been found that Ukrain, given intraperitoneally (i.p.), did not influence the threshold for maximal electroconvulsions in mice. Ukrain in doses of 9.5 and 19 mg/kg significantly enhanced the protective efficacy of valproate, decreasing the ED50 values. However, Ukrain had no effect on the protection provided by diazepam, carbamazepine, diphenylhydantoin and phenobarbital. The combined treatment with Ukrain and anti-epileptic drugs did not cause any signs of toxicity.

Alkaloids↗
PubMed1992

Effect of three months treatment with Ukrain on peripheral blood morphology in rodents.

Studies on Albino Swiss mice and Wistar rats have demonstrated that Ukrain administered intraperitoneally (i.p.) for three months produces the following effects in the haematologic parameters: increased leucocytes and decreased thrombocytes. The haemoglobin and erythrocyte levels, as well as haematocrit value, were unchanged. In the leucogram changes were observed; i.e., a fall in the number of neutrophil segments and an increase in the lymphocyte count. The erythrocyte indices, P.C.V., M.C.V., M.C.H. and M.C.H.C. were not changed by a period of three months i.p. Ukrain administration. The observed changes were more marked in female than in male animals and were greater in mice than in rats.

Alkaloids↗
PubMed1992

Effect of single and three months treatment with Ukrain on aminotransferases (ALT and AST) and on the serum protein level in rodents.

The influence of Ukrain on the activity of aminotransferases (ALT and AST) and on the serum total protein content was estimated in mice and rats of both sexes receiving single or repeated doses of the drug. It was found that one hour after intraperitoneal (i.p.) administration of Ukrain no characteristic changes were recorded in the activity of the investigated enzymes, or in the serum protein content of animals of either sex. Similar effects were observed after three months treatment with Ukrain in rats of either sex. Only in mice receiving Ukrain for three months was a rise in ALT and AST activity found. No particular changes were observed in the total serum protein level, except for a small decreases in the sera of male mice.

Alanine Transaminase↗
PubMed1992

Effect of single and prolonged administration of Ukrain on prolactin concentration in rats.

The effect of single and prolonged administration of Ukrain on the serum prolactin concentrations in rats of both sexes was investigated. One hour after intraperitoneal (i.p.) administration of Ukrain in rats, in doses of 7, 14 and 28 mg/kg, the drug did not affect their serum prolactin concentration. Only in a dose of 28 mg/kg did this drug decrease serum prolactin in a group of female rats. Repeated i.p. treatment (once daily for three months) with 7, 14 and 28 mg/kg of Ukrain significantly increased the serum prolactin concentration in rats of both sexes. The most marked effect was observed in the group of female rats.

Alkaloids↗
PubMed1992

Interaction between Ukrain and aminophenazone in analgesic tests in rodents.

The effect of Ukrain on the analgesic activity of aminophenazone was studied in mice and rats. Antinociceptive action induced by aminophenazone in doses of 50 or 100 mg/kg intraperitoneally (i.p.) was determined by using the writhing syndrome, hot-plate tests and tail-flick latency. The action of aminophenazone was significantly enhanced by Ukrain in the writhing syndrome test and in the tail-flick test. Antinociceptive action of aminophenazone was decreased by Ukrain in the hot-plate test in mice. These results suggest that Ukrain, given simultaneously with aminophenazone, changes susceptibility of animals to nociceptive reaction in the tests performed.

Acetates↗
PubMed1991

Influence of MK-801 on the anticonvulsant activity of antiepileptics.

MK-801 (a potent non-competitive antagonist of N-methyl-D-aspartic acid-mediated events) in subcutaneous doses of 0.1 and 0.2 mg/kg increased the threshold for electroconvulsions and in doses of 0.0031 and 0.0125 mg/kg enhanced the protective activity of valproate against maximal electroshock-induced convulsions in mice. Valproate-induced side-effects (evaluated by means of dark-avoidance acquisition and retention testing and the chimney test) at its ED50 against maximal electroshock (i.e. 268 mg/kg) were pronounced whereas they were absent in the case of a combined treatment with MK-801 (0.0125 mg/kg) and valproate (91 mg/kg). This treatment provided 50% protection against maximal electroshock-induced seizures. Moreover, MK-801 (0.0125 and 0.05 mg/kg) potentiated the anticonvulsant action of phenobarbital, reducing phenobarbital-induced motor impairment totally at 0.05 mg/kg, but did not influence the protection offered by carbamazepine and diphenylhydantoin at 0.05 mg/kg. The N-methyl-D-aspartic acid antagonist did not affect the total plasma levels of either valproate or phenobarbital (as measured by immunofluorescence), so a pharmacokinetic interaction, in terms of total plasma levels at least, is unlikely to be involved in the observed effects. The finding that the combined treatment of MK-801 with valproate or phenobarbital, apart from the distinct potentiation of their anticonvulsant activities, is devoid of side-effects should be carefully considered.

Animals↗
PubMed1991

Influence of antidepressant drugs on seizure susceptibility and the anticonvulsant activity of valproate in mice.

The tricyclic antidepressants, amitriptyline (20-30 mg/kg, i.p.) and imipramine (30-40 mg/kg), provided a significant protection against electro-convulsions (12 mA, 0.2 s stimulus duration) but desipramine (up to 40 mg/kg) remained ineffective. On the other hand, all drugs, amitriptyline (10 mg/kg), desipramine (20 mg/kg), and imipramine (20 mg/kg) distinctly potentiated the protective efficacy of valproate against maximal electroshock, reducing its ED 50 values from 255 mg/kg to 150, 135, and 128 mg/kg, respectively. In one case the plasma valproate level was measured and it was evident that desipramine (20 mg/kg) did not affect the plasma level of this antiepileptic.

Amitriptyline↗
PubMed1991

Influence of CGS 15943 A (a nonxanthine adenosine antagonist) on the protection offered by a variety of antiepileptic drugs against maximal electroshock-induced seizures in mice.

CGS 15943 A (a nonxanthine adenosine antagonist) was studied on the protective efficacy of carbamazepine (60 min prior to the convulsive test), diazepam (60 min), diphenylhydantoin (120 min), phenobarbital (120 min), and valproate (30 min) against maximal electroshock-induced convulsions in mice. Moreover, the influence of the adenosine antagonist on 2-chloroadenosine (1 mg/kg, 20 min prior to the test)- and valproate (250 mg/kg, 30 min)-induced inhibitions of locomotor activity was also studied. CGS 15943 A (1 mg/kg) was given 15 min before both tests and all the drugs were administered i.p.. The adenosine antagonist (1 mg/kg) remained without influence upon the protective activity of all studied antiepileptics, reflected by their respective ED50 values against maximal electroshock. However, both 2-chloroadenosine and valproate-induced inhibitions of locomotor activity were attenuated by CGS 15943 A, which alone did not affect this parameter. However, CGS 15943 A (5 mg/kg) diminished the protection offered by diphenylhydantoin, increasing its ED50 value from 13 to 16 mg/kg. It may be concluded that the protection provided by common antiepileptic drugs against electroconvulsions seems independent of adenosine-mediated inhibition. In the case of diphenylhydantoin, one may suggest the involvement of purinergic transmission in the final anticonvulsant effect.

Adenosine↗
PubMed1990

Effects of calcium channel inhibitors upon the efficacy of common antiepileptic drugs.

Diltiazem and nifedipine (both 1.25 mg/kg) markedly potentiated the protective action of carbamazepine and diphenylhydantoin against maximal electroshock-induced seizures in mice. These calcium channel inhibitors retained their activity at lower doses. Diltiazem and nifedipine (2.5 mg/kg) also moderately potentiated the efficacy of phenobarbital and valproate. Verapamil (up to 10 mg/kg) was not effective against the action carbamazepine, diphenylhydantoin, phenobarbital, and valproate. None of the calcium channel inhibitors used (up to 40 mg/kg) influenced aminophylline-induced convulsions and mortality. Moreover, the anti-aminophylline activity of valproate and phenobarbital was not potentiated by the calcium channel inhibitors in doses up to 10 mg/kg. Further, combination of carbamazepine, ethosuximide, and trimethadione with the calcium channel inhibitors (up to 10 mg/kg) did not offer any protection against aminophylline-induced convulsions. It can be concluded that calcium channel inhibitors enhance the protective efficacy of some antiepileptics against electroconvulsions. A pharmacokinetic interaction does not seem to be responsible for this effect.

Aminophylline↗
PubMed1990

Differential effects of agents enhancing purinergic transmission upon the antielectroshock efficacy of carbamazepine, diphenylhydantoin, diazepam, phenobarbital, and valproate in mice.

L-phenylisopropyladenosine (L-PIA; a preferential A1 adenosine agonist-0.05 mg/kg) offered no protection against electroconvulsions in mice but potentiated the anticonvulsant action of diazepam and valproate against maximal electroshock-induced seizures, decreasing the respective ED50 values from 9.5 to 4.0 mg/kg and from 250 to 185 mg/kg. However, it remained without effect on the protective activity of phenobarbital, carbamazepine and diphenylhydantoin. 5'-N-ethylcarboxamidoadenosine (NECA; a preferential A2 adenosine agonist-0.5 mg/kg) potentiated the efficacy of valproate. On the other hand, NECA (1 mg/kg) diminished the anticonvulsant action of phenobarbital (ED50 was elevated from 16.5 to 20.5 mg/kg), possessing no effect upon the protective action of carbamazepine. In addition, papaverine (20 mg/kg) significantly enhanced the protective efficacy of valproate and up to 40 mg/kg remained without influence upon the protective action of carbamazepine. However, papaverine (20 and 40 mg/kg) inhibited the anticonvulsive potential of phenobarbital. In the light of the results obtained A1 and A2 adenosine receptor-mediated events seem to possess different influences upon the protective effects of antiepileptic drugs.

Adenosine↗
PubMed1990

Influence of calcium channel inhibitors upon the anticonvulsant efficacy of common antiepileptics against pentylenetetrazol-induced convulsions in mice.

Among three calcium channel inhibitors studied, nifedipine (20 mg/kg) moderately inhibited pentylenetetrazol (115 mg/kg, s.c.)-induced convulsions, whilst diltiazem (up to 20 mg/kg) and verapamil (up to 20 mg/kg) were without effect. The combinations of nifedipine (10 and 20 mg/kg) with valproate (100 mg/kg) or phenobarbital (6.25 mg/kg) resulted in significant protection against pentylenetetrazol-induced seizures. Combined treatment of nifedipine (5-20 mg/kg) with ethosuximide (100 mg/kg) also provided a clearcut anticonvulsant action. The antiepileptic drugs alone, in the above doses, were ineffective. The combination of diltiazem (10-20 mg/kg) and ethosuximide (100 mg/kg) produced protection against pentylenetetrazol, comparable to that of ethosuximide (200 mg/kg) alone. No pharmacokinetic interactions were found in the case of ethosuximide, whilst nifedipine (10 mg/kg) increased the levels of phenobarbital and valproate in plasma. The combination of diltiazem with the remaining antiepileptics were ineffective. Verapamil (up to 20 mg/kg) was without effect upon the action of the antiepileptic drugs tested. Finally, none of the calcium channel inhibitors studied influenced the action of diazepam (0.2 mg/kg). It may be concluded that combinations of ethosuximide, with either nifedipine or diltiazem, may be promising for the treatment of absence epilepsy.

Animals↗
PubMed1990

[Morphologic and toxicologic evaluation of response to subcutaneous para-osseous implants Medpol-1 and Medpol-2 in rats].

Cobalt alloys produced in Poland and meant for orthopedic implants were morphologically and toxicologically evaluated. They were implanted subcutaneously in the para-osseous region of rats' heads. The results of the experimental tests strongly suggest the advisability of a clinical research project (study) on the examined cobalt alloys: Medpol-1 and Medpol-2.

Animals↗
PubMed1989

Effect of aminophylline upon the protective activity of common antiepileptic drugs and their plasma levels in mice.

Aminophylline (50 mg/kg) decreased the protective efficacy of carbamazepine (20 mg/kg), diphenylhydantoin (8-12 mg/kg), phenobarbital (20 and 25 mg/kg), and valproate (250 and 300 mg/kg) against electroconvulsions in mice. On the other hand, aminophylline (5 mg/kg) was devoid of such activity. Plasma levels of antiepileptic drugs were measured with the help of the Abbott TDx analyzer and after administration of carbamazepine (20 mg/kg), diphenylhydantoin (10 mg/kg), phenobarbital (25 mg/kg), and valproate (250 mg/kg) were as follows: 8.61, 6.48, 24.3 and 329 micrograms/ml, respectively. Aminophylline (50 mg/kg) remained without any significant influence upon these plasma levels. This may lead to the conclusion that aminophylline-induced reversal of antiepileptic drug activity is not dependent upon a pharmacokinetic mechanism and probably occurs at the neuronal level.

Aminophylline↗
PubMed1989

The role of the central serotonergic system in pilocarpine-induced seizures: receptor mechanisms.

Modification of central serotonergic transmission resulted in alterations of pilocarpine convulsive activity in male Wistar rats. Seizure activity was increased after pizotifen injection and the latency period to onset of convulsions was shortened in animals pretreated with mianserine and quipazine. Stimulation of 5-HT1A receptors with 8-hydroxy-di-N,N-propylaminotetralin (8-OH-DPAT) and blockade of 5-HT1B receptors with cyanopindolol resulted in seizure protection. Intracerebroventricular injections of 5,6-dihydroxytryptamine (5,6-DHT) did not change the protective effect of cyanopindolol. Other agents specifically affecting serotonergic receptors, the agonists 1-(3-chlorophenyl)piperazine (mCPP) and 5-methoxytryptamine (5-MT) and the antagonists spiperone, metergoline, methysergide, cyproheptadine and metoclopramide, did not influence pilocarpine-induced seizures. In conclusion, the present study suggests that the inhibition of pilocarpine-induced seizures may be mediated by stimulation of 5-HT1A and by blockade of 5-HT1B receptors, located probably on the cholinergic terminals.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1988

Differential effects of non-steroidal anti-inflammatory drugs on seizures produced by pilocarpine in rats.

The muscarinic cholinergic agonist pilocarpine induces in rats seizures and status epilepticus followed by widespread damage to the forebrain. The present study was designed to investigate the effect of 5 non-steroidal anti-inflammatory drugs, sodium salicylate, phenylbutazone, indomethacin, ibuprofen and mefenamic acid, on seizures produced by pilocarpine. Pretreatment of rats with sodium salicylate, ED50 103 mg/kg (60-174), and phenylbutazone, 59 mg/kg (50-70) converted the non-convulsant dose of pilocarpine, 200 mg/kg, to a convulsant one. Indomethacin, 1-10 mg/kg, and ibuprofen, 10-100 mg/kg, failed to modulate seizures produced by pilocarpine. Mefenamic acid, 26 (22-30) mg/kg, prevented seizures and protected rats from seizure-related brain damage induced by pilocarpine, 380 mg/kg. These results indicate that non-steroidal anti-inflammatory drugs differentially modulate the threshold for pilocarpine-induced seizures.

Animals↗