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Biomedical subjects

L Szporny

Publications and source records attributed to L Szporny.

At least 19 recordsLinked to original sources

Comparative pharmacology of a 1:10 combination of indomethacin-sodium salicylate.

It has been found that gastrointestinal side-effects of indomethacin could be abolished when administered in combination indomethacin:sodium salicylate (ratio 1:10). In this paper comparative pharmacological data of this combination and its basal compounds are presented. Acute toxicity of the combined preparation was 72 times less in rats than that of indomethacin alone. All therapeutic indexes were markedly increased in the combination of indomethacin-sodium salicylate compared with the separate drug treatments.

Animals

Metabolism of mesocarb in the rat.

1. Rats treated orally with [14C]mesocarb (I; 3-(1-methyl-2-phenyl[2-(14C]ethyl)-N-(phenylaminocarbonyl)sydnone imine) (50 mg/kg) excrete 35% of the radioactivity in 24 h urine and 51% in 48 h urine. 2. Only traces of unchanged drug were found in urine. Hydroxy-mesocarb (II), dihydroxy-mesocarb (III), amphetamine (VII) and the conjugates of II and III account for 86% of the urinary radioactivity. 3. Cannulated male rats excrete about 40% of the radioactivity in 30 h in bile, mainly as conjugates of II and III.

Amphetamine

Kinetic metabolism of vinpocetine in the rat.

The pharmacokinetics of vinpocetine (Cavinton), a new potent vasodilator, and of its main metabolite have been studied in rats by specific extraction and radio thin-layer chromatography following i.v. and p.o. administration. The drug is rapidly eliminated, its half-life was found to be 125 min. The apparent volume of distribution was 3.8 l/kg and the clearance rate 33 ml/min/kg. From the equation describing the concentration-time curve a two-compartement open model was computed. Bioavailability of vinpocetine after p.o. administration was about 50%. The main metabolite, free apovincaminic acid, is formed very rapidly in rats and is eliminated from plasma with a half-life of 360 min.

Administration, Oral

Pharmacokinetics of vinpocetine in humans.

The pharmacokinetics of ethyl-apovincaminate (vinpocetine, Cavinton), a new vincamine derivative has been studied in volunteers after p.o. and i.v. administration. The concentration of the drug was determined by mass-fragmentography in human plasma. There was a biphasic elimination of the substance after i.v. injection with a T1/2 alpha of 0.136 h and with a T1/2 beta of 4.83 h. The value of Vdss (2.1 l/kg) shows a high adsorption of the drug by tissue proteins. The clearance rate of elimination was 0.366 l/h/kg. Oral administration of the drug resulted in maximum plasma concentration 1--1.5 h after the administration with values of 20--62 ng/ml. The bioavailability of the drug--calculated from the ratio of the areas under the concentration-time curves--proved to be 56.6 +/- 8.9%. Unchanged vinpocetine could not be detected in urine. From the results two-compartment open models were constructed and the steady state concentrations after multiple dosing were computed.

Administration, Oral

Effects of 3-trifluoromethyl-alpha-ethylbenzhydrol (RGH-3332), a new enzyme inducer, on the microsomal drug metabolism. Part I.

Intensity and duration of action of several compounds which are metabolized in the liver, are reduced in rats following pretreatment with 3-trifluoromethyl-alpha-ethylbenzhydrol (RGH-3332, Zixoryn), e.g., hexobarbital, methohexitone, glutethimide, hydroxymephenesine, chlorzoxazone, zoxazolamine, ketamine, chlordiazepoxide, diphenylhydantoin, ethylmorphine and pentylenetetrazol, hydroquinone, acenocumarol, respectively. Hypnotic effect of barbital is not altered by RGH-3332. Hexobarbital, meprobamate, mephenesine, nikethamide, canrenone, metyrapone, antipyrine, bromsulphophthalein, inocyanin green, bilirubin disappearance are enhanced, excretion of ascorbic acid is increased after RGH-3332 treatment. The effect of RGH=3332 is inhibited by D,L-ethionine. Hepatic cytochrome P450 concentration is increased following treatment with RGH-3332. Results of in vivo studies proved that 3-trifluoromethyl-alpha-ethylbenzhydrol has enzyme inducing activity.

Animals

Effects of 3-trifluoromethyl-alpha-ethylbenzhydrol (RGH-3332), a new enzyme inducer on the central nervous system of rats. Part II.

3-Trifluoromethyl-alpha-ethylbenzhydrol (RGH-3332, Zixoryn) had been reported to induce the hepatic mixed function oxydase system similarly to phenobarbital [5]. CNS effects of both compounds were tested on immature rats, age 14 days, in the developmental phase of quick morphological and functional growth. A marked difference in total locomotor activity, exploratory behaviour and reaction to both compounds between immature and adult rats is reported. Toxicity of RGH-3332 is favourable in itself and in comparison to that of phenobarbital in both age groups. CNS effects are neglibile compared to the main effect, they can be observed only in 6--8fold doses eliciting maximum inductive response in case of RGH-3332, while CNS effects are caused by phenobarbital at lower doses than that required for maximum inductive response.

Animals

Tape test as a simple new method for the study of compounds increasing the problem-solving ability of the rat.

A simple new method, the "tape test" has been developed for studying the enhancement of learning by drugs in "learning-dull" rats. A piece of adhesive tape is pressed on the left front pad of the rats. The time of tape removal by the animal, i.e., the problem-solving time is measured. In our experiments the selected learning-dull rats were used which were unable to remove the tape within 60 s observed on 3 consecutive days. The problem-solving ability of the rats was studied on 4 consecutive days, by posttrial administration. The problem-solving ability was found to be increased after treatment with different drugs such as para-chlorphenylalanine (PCPA), pemolin, orotic acid, vitamin B12. The stimulatory effect of vitamin B12 could be inhibited by vincristine.

Animals

General and cerebral haemodynamic activity of ethyl apovincaminate.

Systemic and cerebral haemodynamic effects of ethyl apovincaminate (RGH-4405, Cavinton), a new compound, have been investigated in anaesthetized dogs. The compound was administered i.v. and produced an increase in cerebral blood flow accompanied by a decrease in cerebral vascular resistance which persisted for 15 min. The effective dose was 0.2-0.5 mg/kg. Mean arterial blood pressure, total peripheral resistance and cardiac work were decreased, heart rate and cardiac output were increased. Cerebral metabolic rate of oxygen was enhanced. It is assumed that the compound has a direct effect on cerebral metabolism. RGH-4405 has a weak antiarrhythmic and coronary dilating activity. Its effect on smooth muscle is more marked than that of papaverine. RGH-4405 appears to be a potent cerebral vasodilator enhancing cerebral metabolism.

Animals

Protective activity of ethyl apovincaminate on ischaemic anoxia of the brain.

Effects of ethyl apovincaminate (RGH-4405, Cavinton), a new cerebral metabolic and vasodilatory agent, on cerebral regulatory functions under ischaemic anoxia were studied on immobilized cats by EEG. Cortical resistance time increased and recovery time decreased for a long period after i.v. administration of the compound. Results point to the possibility of further enhancement of cerebral regulatory processes by specific drug effects. It is assumed that tolerance or adaptation to hypoxia might be increased by RGH-4405 if spontaneous regulatory processes are impaired.

Animals

Effects of ethyl apovincaminate on the central nervous system.

Side effects of ethyl apovincaminate (RGH-4405, Cavinton), a cerebral vasodilatory agent, on the central nervous system were studied on mice and rats. Anticonvulsive effect in electroshock was observed as major CNS effect, locomotor activity was reduced due to muscle relaxant effect. The compound had no sedative effect on rodents. Its analgesic effect was negligible. Cavinton had neither antidepressive, nor anticholinergic activity.

Animals