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P Potier

Publications and source records attributed to P Potier.

At least 73 records · Page 4Linked to original sources
PubMed1987

Synthesis of (pGlu-5, MePhe-8, Sar-9) substance P (5-11) (DiMe-C7) using a polyacrylamide resin and biological activity on guinea pig ileum and tracheal smooth muscle.

DiMe-C7 (pGlu-Gln-Phe-MePhe-MeGly-Leu-MetNH2), a metabolically stable analogue of Substance P, was prepared by solid-phase peptide synthesis using a polyacrylamide resin and a labile anchorage derived from glycolic acid. Myotropic activities in guinea pig ileum (ED50 = 4.0 +/- 1.5 10(-8) M) and guinea pig trachea (ED50 = 8.6 +/- 3.5 10(-8) M) are discussed in comparison with the corresponding activities of Substance P.

Animals↗
PubMed1987

Molecular structure of 3-(methoxycarbonyl) amino-beta-carboline, a selective antagonist of the sedative effects of diazepam.

The X-ray crystal structure of 3-(methoxycarbonyl) amino-beta-carboline, a selective antagonist of the sedative effects of diazepam having a high affinity for the benzodiazepine receptor, has been determined. The results were compared with structural information obtained from this compound, both in the solid state and in dilute solution, by use of Fourier transform infrared spectroscopy. Its X-ray structure was also compared with those of two other active beta-carbolines, methyl beta-carboline-3-carboxylate and N-ethyl-3-carbamoyl-beta-carboline. The crystal packing characteristics of 3-(methoxycarbonyl) amino-beta-carboline differ from those of these two beta-carbolines in both the pattern of intermolecular hydrogen bonding and the quality of their pi-pi stacking interactions. The relevance this may have to the selective activity of 3-(methoxycarbonyl) amino-beta-carboline is discussed.

Carbolines↗
PubMed1986

Therapeutic response to taxol of six human tumors xenografted into nude mice.

To test the antineoplastic activity of taxol, a natural product isolated from yew (Taxus baccata L.), six human tumors transplanted into athymic mice were used (primary tumors of breast, endometrium, ovary, brain, lung and a recurrence of tongue tumor). While the growth rates varied with the histopathological characteristics of different tumor types, all mice were treated at a mean tumor volume of 200 +/- 8 mm3. Taxol was given SC at a dose level of 12.5 mg/kg per injection per day for 5 consecutive days out of 7 over a period of 3 weeks. With this schedule antitumor responses were obtained in all of the six neoplasms xenografted into nude mice. In the case of the ductal carcinoma of the breast total tumor regressions were observed in four of the five treated animals. In the five other experimental models taxol produced significant growth delays. We believe that the results of these initial tests on the nude mouse--human tumor xenograft system are convincing and justify clinical assessment of this drug.

Adult↗
PubMed1985

3-Amino-beta-carboline derivatives and the benzodiazepine receptor. Synthesis of a selective antagonist of the sedative action of diazepam.

Seven 3-N-substituted derivatives of 3-amino-beta-carboline were synthesized and their affinities for the benzodiazepine receptor were assessed in vitro. Two compounds, 3-(ethylamino)-beta-carboline and 3-[(methoxycarbonyl)amino]-beta-carboline (beta-CMC), showing IC50 values of 460 and 71 nM, respectively, were selected for in vivo studies. The former compound showed long-lasting proconvulsant activity in Papio papio baboons while beta-CMC was shown in mice to selectively antagonize the sedative effects of diazepam without exhibiting convulsant, proconvulsant, or anxiogenic activity by itself.

Animals↗
PubMed1985

[Presence of a peripheral type benzodiazepine binding site on the macrophage; its possible role in immunomodulation].

Saturable binding site for 3H-flunitrazepam (KD = 43 +/- 7 nM, Bmax = 391 +/- 58 fmoles/cell, i.e. 250,000 sites/cell) is characterized on Mouse peritoneal inflammatory macrophages. The affinity for different ligands (PK 11195 greater than Ro 5-4864 greater than diazepam greater than flunitrazepam greater than clonazepam greater than Ro 15-1788) shows that this site is of peripheral type. In vivo the humoral response in Mice to Sheep red blood cells was stimulated by administration of 1 mg/kg of PK 11195 (+85%), Ro 5-4864 (+80%) and diazepam (+58%). Clonazepam and Ro 15-1788 are devoid of activity. This suggests that molecules which show affinity for the "peripheral type" benzodiazepine binding site might modulate the immune response.

Animals↗
PubMed1984

Relationships between the structures of taxol and baccatine III derivatives and their in vitro action on the disassembly of mammalian brain and Physarum amoebal microtubules.

The in vitro disassembly of microtubules from mammalian brain and Physarum is inhibited by various derivatives of taxol and baccatine III. Structure-activity relationships of the taxol derivatives were identical for both mammalian brain and Physarum microtubules. This observation suggests that the site of action of taxol has been preserved during the evolution of these two different eukaryotic lines. The substituent at C-13 of taxol was required to prevent disassembly of brain microtubules with or without microtubule-associated proteins. In contrast, both taxol and baccatine III prevented the disassembly of Physarum microtubules to the same extent, showing that the substituent at C-13 was not required in the interaction with Physarum tubulin. The different effects of baccatine III and taxol derivatives indicate that measuring the disassembly of microtubules from different organisms could be a useful parameter in the search for derivatives exhibiting antiparasitic activity.

Alkaloids↗
PubMed1983

[Action of taxol on human tumors transplanted in athymic mice].

In order to study the antitumour activity of taxol (a diterpene of the taxane type) isolated from Yew: Taxus baccata L. (Taxacae), human tumours implanted as xenografts in athymic Mice were used. Swiss nude mice were treated subcutaneously (12.5 mg/kg/injection/day for 5 consecutive days out of 7, over a period of 3 weeks). Treatment by taxol of a liver metastasis of a breast tumour, a tongue primary tumour and a skin metastasis of bronchial carcinoma gave statistically significant results (0,01 greater than P greater than 0,001 and P less than 0,001). However, taxol showed a very moderate antitumour activity against a transplanted primary tumour of the colon.

Adult↗
PubMed1982

Methyl-beta-carboline-induced convulsions are antagonized by Ro 15-1788 and by propyl-beta-carboline.

Injected i.v. into baboons, Ro 15-1788 (a benzodiazepine antagonist) and propyl-beta-carboline-3-carboxylate did not modify either the behavior or the electroencephalogram at doses up to 2 mg/kg. Methyl-beta-carboline-3-carboxylate is a potent convulsant at doses of 20 micrograms/kg in photosensitive baboons and 100 micrograms/kg in non-photosensitive baboons. These convulsive doses of methyl-beta-carboline-3-carboxylate are effectively antagonized by 0.5 mg/kg of Ro 15-1788 and also by 2 mg/kg of propyl-beta-carboline-3-carboxylate.

Animals↗
PubMed1981

Proconvulsant effects in baboons of beta-carboline, a putative endogenous ligand for benzodiazepine receptors.

beta-Carboline-3-carboxylic acid ethyl ester (beta-CCE) was tested on two models of epilepsy in the baboon: kainic acid-induced limbic status epilepticus and photosensitive epilepsy. Beta-CCE, at very low doses ranging from 8 to 100 microgram/kg (i.v.), induced a reactivation of the limbic focus and photomyoclonic and generalized seizures in photosensitive and non-photosensitive baboons. The proconvulsant effect of beta-CCE may be associated with its binding to a particular subclass of benzodiazepine receptors.

Amygdala↗
PubMed1979

[Recent results in the field of vinblastine group antitumour alkaloids. Biochemical studies].

Studies on the interaction between vinblastine-like alkaloids and their receptor, i.e. tubulin, are reported. They shed some light on the structure-activity relationships in this medicinally important series: the configuration at C14' and C16', as well as the presence of the methoxycarbonyl group on C16' seem to play an essential role in the determination of biological activity. A new analogue, detected by its specific behaviour with tubulin, was found, in vivo, to be as active and less toxic than vinblastine.

Animals↗
PubMed1978

Interaction of vinblastine analogues with tubulin.

Studies of the interaction between vinblastine-like alkaloids and their receptor, i.e. tubulin, are reported. They shed some light on the structure-activity relationships in this medicinally important series: the configurations at C14' and C16' as well as the presence of the methoxycarbonyl group on C16' seem to play an essential role in the determination of biological activity.

Glycoproteins↗