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Biomedical subjects

R Samardzić

Publications and source records attributed to R Samardzić.

At least 55 records · Page 3Linked to original sources
PubMed1981

Comparison of behavioral changes in cats treated with intracerebroventricular 6-hydroxydopamine and reserpine.

In singly- and group-housed cats, an intraventricular injection of 6-hydroxydopamine (6-OHDA) in doses up to 1.0 mg, after a latent period of 1 to 3 days, evoked motor responses including tremor, ataxia, rigidity, weakness with adynamia and clonic-tonic convulsions. However, the intraventricular administration of 6-OHDA in a dose of 2.0 mg in group-housed cats, also after a latent period of 1 to 3 days, caused aggression, a restlessness, irritability, rage, fear, threat, attack, fighting and flight. These responses were accompanied by autonomic signs of mydriasis and dyspnoea and motor changes including tremor, ataxia, rigidity, weakness with adynamia and clinic-tonic convulsions. In the singly-housed cat only the latter motor phenomena were observed after the higher dose. Intraventricular injection of reserpine (0.5-1.0 mg) in both singly- and group-housed cats produced catalepsy, sedation, miosis, ptosis, defecation and micturition as well as motor responses of tremor, rigidity and akinesia. It is concluded that although 6-OHDA and reserpine evoke different behavioral effects, the motor changes are similar.

Affect↗
PubMed1979

Evidence of central cholinergic mechanisms in the appearance of affective aggressive behaviour: dissociation of aggression from autonomic and motor phenomena.

Carbachol, muscarine, eserine and neostigmine injected into the cerebral ventricles of conscious cats evoked emotional behaviour with aggression, autonomic and motor phenomena as well as clonic-tonic convulsions. The main and the most impressive feature of the gross behavioural effects of intraventricular carbachol, muscarine, eserine and neostigmine in conscious cats was the affective type of aggression. However, neostigmine produced aggressive behaviour only in about one-quarter of the experiments. After intraventricular hemicholinium-3 and triethylcholine carbachol, muscarine, eserine and neostigmine elicited autonomic and motor phenomena. In these cats cholinomimetics and anticholinesterases evoked only slight hissing and snarling. Choline administered into the cerebral ventricles of hemicholinium-3 and triethylcholine-treated cats restored the emotional behaviour with aggression, autonomic and motor phenomena as well as clonic-tonic convulsions to intraventricular carbachol, muscarine, eserine and neostigmine. The restored gross behavioural changes to eserine were almost of the same intensity, while those to carbachol and muscarine were of lesser intensity than in control cats. From these experiments it is concluded that cholinergic neurones are involved in the appearance of the affective type of aggression resulting from intraventricular carbachol, muscarine, eserine and neostigmine.

Aggression↗
PubMed1978

[Method for simultaneous study of peristaltic and pendular movements of isolated rabbit ileum].

A method is described for studying simultaneously the peristalsis and the pendular movements in the isolated pieces of rabbit ileum. At the same time, using this method it is possible to analyse the actions of drugs on the mechanisms which ensure the pendular movements and the propulsive activity, as well as their relationship. The method is relatively simple and only classical and commercially available equipments are needed. With this method the records and the volume of fluid expelled are suitable for statistical analysis.

Animals↗
PubMed1978

[Distribution of 1-14C palmitic acid in brain tissue after intraventricular injection in the conscious cat].

The distribution of (1-14C) palmitic acid in the brain tissue following the injection into the cerebral ventricles of conscious cats was investigated. The radioactive material was found in the brain tissue surrounding the cerebral ventricles and in the cerebral cortex, but in varying amounts : the smallest amounts were found in the cerebral cortex, while the highest in the thalamus and in the hippocampus. Radioactive material was also found in the peripheral venous blood. The amount of the radioactive material in the grey matter lining the cerebral ventricles as well as in the cerebral cortex was time-dependant. The labelled material in the structures surrounding the cerebral ventricles and in the cerebral cortex increased within first four hours after its intraventricular administration. Thereafter, throughout subsequent 48 hours either it slowly disappeared in the caudate nucleus and in the thalamus, or it was retained in the hypothalamus and in the floor of the IV ventricle.

Animals↗
PubMed1978

[Metabolism of (1-14C)-palmitic acid in the cat's brain].

Following injection into the cerebral ventricles of conscious cats, (1-14C) palmitic acid was rapidly taken up and incorporated into a variety of brain lipids. The peak of uptake of (1-14C) palmitic acid, about 50% of injected radioactive material, into the brain tissue was obtained within the first 24 h following its administration. Thereafter, the radioactivity slowly decreased reaching the least value by the end of the second week. The most heavily labelled lipids were the phospholipids, while the free fatty acids were appreciably labelled. Small percentage of the radioactive material was found in monoglycerides, diglycerides and triglycerides. The least incorporation was into cholesterol esters.

Animals↗
PubMed1977

Muscarine- and carbachol-induced aggressions: fear and irritable kinds of aggressions.

In unaneasthetized and unrestrained cats, muscarine and carbachol were injected into the cerebral ventricles. The kind of aggressive behaviour depended on the cholinomimetic drug and was classified as fear and an irritable kind of aggression. Muscarine induced the fear kind of aggression. The aggressive behaviour was usually preceded by attempts to escape and the attack was relevant to the situation. For the attack the presence of some threatening agent was needed. The aggression was accompanied by intense motor but less autonomic activation. On the other hand, carbachol induced an irritable kind of aggression and had the following characteristics: for the attack the presence of some threatening agent was not needed; the attack was not relevant to the situation; the aggression was not preceded by attempts to escape; and the aggressive behaviour was accompanied by intense motor and autonomic activation. It is concluded that cholinoceptive mechanisms are involved in the control of aggressive behaviour.

Aggression↗
PubMed1977

[Pharmacological analysis of the peristalsis block induced by magnesium applied at the serosal and mucosal surfaces of the isolated guinea pig ileum].

Acetylcholine, metacholine, eserine and neostigmine, acting from the serosal surface antagonised the peristaltic block produced by mucosal application of magnesium, as well as when choline esters and anticholinesterases were injected intraluminally and magnesium acted from the serosal side of the guinea-pig isolated ileum. On the other hand, 5-hydroxytryptamine and histamine did not remove the peristaltic block produced by magnesium. It is concluded that cholinoceptive sites within the myenteric plexus which, when stimulated by cholinergic substanced, produce regular peristaltic waves, are accessible from either sides of the guinea-pig isolated ileum.

Acetylcholine↗
PubMed1976

[Pharmacological analysis of the inhibition of peristalsis of the isolated guinea-pig ileum by tetramethylammonium].

Tetramethylammonium in small concentrations contracted the longitudinal muscle of the guinea-pig isolated ileum, but had no effect on the peristaltic reflex. However, in high concentrations, it contracted the longitudinal muscle and blocked the peristaltic reflex. Acetylcholine, methacholine, carbachol, eserine and neostigmine antagonized the peristaltic block previously produced by tetramethylammonium. On the other hand, propionylcholine, butyrylcholine, nicotine, pilocarpine, arecoline, histamine and 5-hydroxytryptamine did not remove the peristaltic block. From these experiments, it is concluded that the predominant sites of the depressive effect of tetramethylammonium on the peristalsis are the cholinoceptive ganglia of myenteric plexus subserving the peristaltic reflex of guinea-pig isolated ileum.

Acetylcholine↗