Farmakologiia i toksikologiia最新文献

A new narcotic analgesic agent phenaridine is superior to fentanyl by the activity and duration of action. It does not cause bronchospasm, exerts no significant influence on the parameters of gas exchange in the blood.

The carcinogenic activity of spyrobromin was studied during the chronic experiment on 1.5-2-month-old rats and mice of both sexes. The drug was administered intragastrically and intraperitoneally once a week in the maximally tolerant dose for 24 months. Under the given experimental conditions spyrobromin can diminish the latent period of the development of tumours in the experimental rats at intraperitoneal administration. At intragastric administration of the drug no decrease was noted in the latent period and no increase of tumours was observed in the experimental groups of the animals as compared with control. Spyrobromin is considered to be a weak carcinogen. The oral route of administration is the most safe with respect to the oncogenic risk.

The effects of two cardioselective beta-blockers metoprolol and atenolol (2 mg/kg, intravenously) on the activity of the sympathetic renal nerve as well as the sensitivity of the chronotropic and sympathetic components of the baroreceptor reflex tested by using phenylephrine or sodium nitroprusside. In the experiments on conscious Wistar rats only the more lipophilic agent metoprolol significantly decreased the baseline level of the activity of the sympathetic nerve by 15%. The sensitivity of the chronotropic baroreceptor reflex elicited by a decrease of arterial blood pressure with sodium nitroprusside was reduced significantly both by metoprolol and atenolol. The tendency towards a decrease of the sensitivity of the chronotropic reflex elicited by phenylephrine-induced elevation of blood pressure was noted. The baroreflectory modification of the sympathetic activity did not change significantly under the influence of metoprolol and atenolol. The presence of the central component of action (of metoprolol) and the peripheral component (of the studied beta-blockers) is concluded.

By using the NMR spectroscopy it was shown that hydrogen bond is formed during the interaction between pyrazole molecule and iecithin. The hydrogen bond formation is probably one of the manifestations of the biological activity of pyrazole.

Serotonin, histamine, tryptophan administered in low doses were shown to protect the rat gastric mucosa against indomethacin-induced hemorrhages. When administered in high doses, serotonin retained the protective properties, while histamine and histidine, on the contrary, increased the hemorrhagic lesion of the tissue. Tryptophan and histidine given in low doses promoted a decrease of the indomethacin elevated levels of serotonin and histamine in the gastric mucosa.

In the experiment of albino rats it was shown that hypobaric hypoxia caused a disorders of hemostasis with destabilization of membranes and imbalance of electrolytes in the erythrocyte-plasma-vessel wall system. Streptase administration in a dose of 2500 U/kg in this case events in some degree the changes in the process of the blood coagulation, viscosity-elasticity properties of erythrocytes, calcium levels in plasma and erythrocytes, sodium and magnium levels in the abdominal aorta wall produced by the "altitude rise" in an altitude chamber.

In the initial period after a single toxic administration of cis-dichlordihydrooxyamine platinum in the rat liver there was found an increase of the contents of total phospholipids (PL) at the expense of the change in the contents of lysofractions as well as phosphatidylcholine (PC), polyglycerophosphates (PGP) and phosphatide acids. There was observed suppression of the antiradical activity leading to intensification of lipid peroxidation (LPO) processes. In the later periods of the experiment the decrease of phospholipid contents is determined by a reduction of the levels of phosphoinosites, sphyngomyelin, PGP. At the same time the processes directed at the restoration begin to function resulting in normalization of some links of LPO and the PL fractions which are the most important during reparation of hepatocytic membranes.

The analgesic properties of new Soviet-made antidepressants pyrasidol, incazan, tetrindol as compared with amitriptyline and their influence on the analgesic effect of acupuncture were studied in experiments on rats by using the method of electrical stimulation of the tail root with stimuli of the increasing intensity. All the studied drugs at single and subchronic (6 days) administration possessed the analgesic actions. Pyrasidol exerted the most pronounced effect. The antidepressants enhanced the analgesic effect of electroacupuncture, in particular during activation of the points of general action and this effect showed up to the greatest degree under medication with pyrasidol.

The test system for selection of antihypoxic compounds was developed and approved on the basis of the model of the perfused rat heart. It was found that the hypoxic state of the moderate degree of severity simulated on the myocardium is optimal for the assessment of the studied antihypoxic compounds. Taking into consideration the fact that at the early stages of hypoxia the electron transport is disordered at the level of the first enzymatic complex of the respiration chain, the protective actions of the agents (menadione and hydroquinone) being able of shunting the respiration chain to bypass the damaged area were studied. It was found that under hypoxia these compounds improve the energy-dependent contractile properties of the myocardium, that is, show up the antihypoxic effects.

Cordaron (amiodaron, angoron, atlansil, cordinil, trangorax) is a drug produced by the French-Belgian firm "Labaz". Some pharmacological properties of cordaron and in particular its ability to increase the refractory period both of the atrioventricular junction and the abnormal pathway that hampers the circulation of excitation between the atria and ventricles influencing the mechanism of reverse excitation provide favourable conditions for elimination of arrhythmias. In a number of papers of the Soviet and foreign authors there are presented the results of cordaron treatment of patients with various cardiac rhythm disorders which indicate a fairly high antiarrhythmic effectiveness of the drug. Its lethal dose is practically absent. Side effects show up only during a prolonged therapy and disappear after the drug withdrawal.