Biomedical subjects

M Filip

Publications and source records attributed to M Filip.

115 records · Page 7Linked to original sources

PubMedDate not supplied

Discriminative stimulus properties of (+)-oxaprotiline in rats.

Using a drug discrimination procedure on a fixed ratio (FR) 10 schedule of reinforcement, rats were trained to distinguish between the stimulus properties of the selective inhibitor of noradrenaline uptake (+)-oxaprotiline ((+)-OXA) and saline. Fifty per cent of the rats that learned to reliably discriminate (+)-OXA from saline, reached high discrimination accuracy. In substitution testing, maprotiline (MAP) and desipramine (DMI) produced dose-related responding on the (+)-OXA lever. (-)-OXA failed to show substitution. The results of our findings demonstrate that (+)-OXA may be used as a discriminative cue in rats. The NA uptake inhibition seems to be involved in the effect of this drug.

Animals↗

PubMedDate not supplied

[The therapeutic prospects in glaucoma treatment].

The appearance of new drugs in glaucoma's treatment has the aim to reduce the ocular hypertonia and to preserve the visual field maintaining the integrity of visual fibres which form the optic nerve. The authors review the drugs which have action on the trabeculum, such as parasympathomimetics, adrenalin, glicocorticoid antihormones and colchicine, also influencing the ciliary processes as inhibitors of carbonic anhydrase, and the drugs which have an action on the uveoscleral paths such as prostaglandines.

Chronic Disease↗

PubMedDate not supplied

[The artificial lens implant].

The paper presents a short history of the cataract intervention, starting from the lens luxation in vitreum and going to the implant of artificial lens. From the three classes of artificial lenses, up-to-date options are the posterior chamber artificial lenses. Today, in 80% of the cases, artificial lens implant is done, 80% of the implanted lenses being posterior chamber lenses. The paper also exposes various operatorial techniques, post-operatorial evolution and the results obtained.

Aphakia, Postcataract↗

PubMedDate not supplied

MP-3022, a new putative antagonist at pre- and postsynaptic 5-HT1A receptors.

The receptor binding and pharmacological profile of the new, putative 5-HT1A receptor antagonist MP-3022 (4-[3-(benzotriazol-1-yl)propyl]-1-(2-methoxyphenyl)piperazine) were studied. Another 5-HT1A receptor antagonist, (S)-WAY 100135 ((S)-N-tert-butyl-3-[4-(2-methoxyphenyl)piperazine-1-yl]-2- phenylpropanamide), was used as a reference drug in functional models. MP-3022 showed a high affinity (Ki) of 25 nM and 69 nM, respectively, at 5-HT1A binding sites and alpha 1-adrenoceptors in vitro. The Ki values of MP-3022 in relation to other binding sites examined (5-HT2A, alpha 2- or beta-adrenoceptors, dopamine D1 and D2) were 20-100-fold lower. In functional studies, MP-3022 significantly attenuated the 8-OH-DPAT (8-hydroxy-2-(di-n-propylamino)tetralin)-induced decrease in the population spike evoked in the CA1 cell layer of the hippocampal slice preparation, without producing its own effects. The 8-OH-DPAT-evoked increase in the corticosterone concentration in the serum as well as the 8-OH-DPAT-mediated decrease in the 5-HT turnover in the hippocampus were attenuated by MP-3022. MP-3022 increased the serum corticosterone concentration only at the highest dose used, but it did not change the 5-HT turnover in the hippocampus. Like MP-3022, (S)-WAY 100135 antagonized the 8-OH-DPAT-induced effects. It has also been demonstrated that (S)-WAY 100135 is devoid of an intrinsic activity at 5-HT1A receptors. The data obtained demonstrate that, like (S)-WAY 100135, MP-3022 behaves like a functional antagonist at pre- and postsynaptic 5-HT1A receptors.

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

PubMedDate not supplied

Effects of MP-3022 on the 8-OH-DPAT-induced discriminative stimulus in rats.

To examine the effects of 4-[3-(benzotriazol-1-yl)-propyl]-1-(2-methoxyphenyl)piperazine (MP-3022), a high affinity 5-HT1A ligand, on the 5-HT1A-induced stimulus effect and to compare its effects with those produced by some 5-HT1A receptor ligands, rats were trained to discriminate between 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), 0.1 mg/kg ip, and saline in a standard, two-lever operant procedure. Substitution studies showed that the 8-OH-DPAT cue was mimicked in a dose-dependent manner by buspirone and ipsapirone, the 5-HT1A receptor partial agonists, but not by 1-(3-chlorophenyl)piperazine (m-CPP), a nonselective 5-HT agonist. Furthermore, the 8-OH-DPAT cue was almost completely blocked by 1-(2-methoxyphenyl)-4-[4-(2-phthalimido)]butylpiperazine (NAN-190), a 5-HT1A receptor and alpha 1-adrenoceptor antagonist, but not by prazosin (a selective alpha 1-adrenoceptor blocker). Our results also demonstrate that the discriminative effect of 8-OH-DPAT may be dose-dependently antagonized by MP-3022, which itself does not mimic the cue. It is concluded that MP-3022 behaves like a full 5-HT1A receptor antagonist in the 8-OH-DPAT-evoked discrimination procedure.

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

PubMedDate not supplied

The role of dopamine receptor subtypes in the discriminative stimulus effects of amphetamine and cocaine in rats.

The role of dopamine (DA) receptor subtypes in the discriminative stimuli of the psychostimulant drugs of abuse amphetamine and cocaine was evaluated by the ability of DA D1, D2 and D3 receptor subtype ligands to either substitute for or antagonize these effects. Separate groups of rats were trained to discriminate between amphetamine (0.5 mg/kg) and saline, and between cocaine (5 mg/kg) and saline. Both the training drugs evoked cross-substitution. In further substitution experiments, (+)-2,3,4,5-tetrahydro-7,8-dihydroxy-1-phenyl-1H -3-benzazepine (SKF 38393; 5-20 mg/kg), a selective D1 agonist, moderately substituted for cocaine, but not for amphetamine. The D2 agonist bromocriptine (2.5-20 mg/kg) mimicked both training drugs' cues. Pramipexole, a D3-preferring agonist, in a dose of 0.5 mg/kg induced over 80% substitution for cocaine, and a weaker one (ca. 62%) for amphetamine. Combination tests with DA antagonists showed that the D1 antagonist (+)-3-methyl-7-chloro-8-hydroxy-1-phenyl-2,3,4,5-tetrahydro-1H -3-benzazepine (SCH 23390; 0.01-2 mg/kg), and the D2 blocker raclopride (0.13-1 mg/kg) significantly (78-100%) attenuated the effects of psychostimulants, while the D3-preferring antagonist cis-(+)-5-methoxy-1-methyl-2-(di-n-propylamino)tetralin (UH 232; 5-20 mg/kg) did not affect them. The present results indicate a critical role of D2 receptor subtypes in the discriminative stimuli of amphetamine and cocaine in rats, as well as a less pronounced involvement of D1 and D3 subtypes in the effects under study.

Amphetamine↗

PubMedDate not supplied

Nitric oxide (NO) pathway and locomotor hyperactivity towards dopaminomimetics in rats.

The effects of the NO donor molsidomine and the inhibitors of the NO synthase (NOS) 7-nitroindazole (7-NI) and NG-nitro-L-arginine methyl ester (L-NAME) on the motor hyperactivity induced by indirect (amphetamine and cocaine) or direct (SKF 38393 and bromocriptine) dopamine (DA) agonists were studied in rats. The hyperactivity induced by 0.5 mg/kg of amphetamine or 5 mg/kg of cocaine was potentiated in a dose-dependent manner by molsidomine (30-100 mg/kg), but attenuated by 7-NI (3-30 mg/kg) or L-NAME (3-30 mg/kg). The NOS inhibitors also inhibited the locomotor hyperactivity evoked by 15 mg/kg of SKF 38393 (a DA D1 agonist) or 5 mg/kg of bromocriptine (a DA D2 agonist). On the other hand, the hyperactivity induced by those direct DA receptor agonists was potentiated by molsidomine. The present findings provide further evidence for an interaction at the behavioral level between NO and the DA-mediated effects of amphetamine and cocaine; moreover, they seem to indicate that both DA D1 and DA D2 receptor subtypes are under such influence.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗