Farmakologiia i toksikologiia最新文献

In the experiments on mice there were analysed the effects of arginine-vasopressin (AVP) and its analogue des-glycine-arginine-vasopressin (DG-AVP) on the extinction of the conditioned reaction of passive avoidance and the reproduction of memory trace in amnesia caused by detaining the animal in the dangerous section of the unit after electrocutaneous stimulation. An increase of resistance of the conditioned reaction to a sharp extinction at systemic administration of AVP and DG-AVP was shown.

Changes in the microcirculatory bed of the rat brain cortex during motor activity and hypodynamia under the action of piracetam, GABA and bicuculline were studied. The possibility of the development of compensatory processes due to the cerebral blood flow increase under the influence of GABA agonists at a disturbance of the cerebral hemodynamics in combination with increased locomotor activity and also due to the improvement of the microcirculation at early stages of hypodynamia induced by administration of GABA agonists opens up new perspectives in the use of GABA-positive drugs.

D, L-carnitine chloride antihypoxic action was studied. Carnitine chloride (100-200 mg/kg) was found to increase mouse life expectancy under different experimental models of hypoxia both at acute and chronic administration.

The liver damage by CCl4 in albino rats was followed by a drastic activation of lipid peroxidation processes and suppression of most components of the antioxidant system. The administration of acetylcysteine to the affected animals exerted the positive effect which manifested itself in a decrease of lipid peroxidation products content in the blood plasma and liver and in the partial normalization of the antioxidant protection system.

Under the conditions of the constancy of the postsynaptic effect of two M-cholinolytics atropine and amizil the relationship between the presynaptic and protective effects of the drugs in DDVF intoxication was studied. The indication of the level of the postsynaptic activity was the suppression by the cholinolytics of tremor reaction in rats induced by the action of arecoline. The presynaptic effect of the drugs was judged by the charge of the "bound" acetylcholine content in the brains of the animals. It was found that when administered in the equieffective by the choline-blocking activity doses, atropine to a greater extent reduced the content of the "bound" acetylcholine which was increased due to the action of DDVF and at the same time it possessed the less pronounced protective activity in intoxication with DDVF than amizil. It is supposed that the removal of the presynaptic suppression of acetylcholine release due to the anticholinesterase substance action deteriorates the prognosis of the course of DDVF intoxication.

The acute administration of the pineal hormone melatonin (1 mg/kg) to rats was shown to increase, and the chronic use to decrease intensity of haloperidol-induced catalepsy with the reorganization of the rhythmic pattern of the neuroleptic effect. The direct opposite shifts were observed after pinealectomy or propranolol chronic administration (1 mg/kg). It is suggested that owing to its own adaptive properties the pineal gland can participate in the formation of drug tolerance.

The effects of antibiotics on functioning glucocorticoid receptors of types II and III of male Wistar rat liver cytosol were studied. All the studied antibiotics at the concentration of 10(-3) M increased 1.6-2.4 times the function of glucocorticoid receptors of type III. At the concentration of 10(-4) M, except cephazolin and kanamycin, all antibiotics also enhanced the function of glucocorticoid receptors of types III, although to a lesser degree than at the concentration of 10(-3) M. The influence of antibiotics on the function of glucocorticoid receptors of type II is diverse. If antibiotics of penicillin and cephalosporin group increased, antibiotics of streptomycin, rifamycin, aminoglycosides and levomicetine group, on the contrary, decreased the function of type II glucocorticoid receptors. The practical importance of the agents regulating the function of glucocorticoid receptors is discussed.

In experiments on rabbits it was found that acute myocardial infarction (AMI) was associated with a disorder of the drainage function the lymphatic system and a drastic increase of the lymph toxicity. The administration of propranolol (obsidan), amiodaron (cordaron), lidocaine (xycaine), trimecaine (mesocaine), nitroglycerin, panangin and heparin exerted the pronounced stimulating action on the lymph outflow rate. Strophanthin-K, corglycon and digo in possessed the moderate lymphogenic effect. Novocainamide (procainamide), verapamil (isoptine) and panangin exerted no influence on the lymph outflow rate. The administration of the above mentioned drugs in the initial period of AMI sharply increased the toxic properties of the lymph; subsequently the lymph toxicity gradually decreased and was less than in control (in AMI treated with drugs).

Mildronate of 3-(2,2,2-trimethylhydrozinium)propionate, a novel anti-ischemic drug, inhibits the biosynthesis of carnitine from Y-butyrobetaine. Continuous administration of mildronate (200, 400 mg/kg for 10 days orally) to rats exerted a marked antiketogenic action on the animals deprived of food for 48 hours. In the fed rats receiving sodium octanoate a course treatment with mildronate elevated to concentration of ketone bodies in blood serum. Selective regulation of carnitine-independent and carnitine-dependent metabolism appears justified for the treatment of such pathological states as ischemic heart disease, diabetes and obesity.