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Biomedical subjects

P Coudert

Publications and source records attributed to P Coudert.

At least 73 records · Page 4Linked to original sources

Comparative effects of some 3-amino 4,6-diarylpyridazines on the biosynthesis in vitro of TXA2 and PGI2- and on the TXA2- and PGI2-synthesizing activities of cardiac tissue.

Some 3-amino 4,6-diarylpyridazine derivatives were tested for their effects on TXA2 and PGI2 biosyntheses in vitro and on the TXA2- and PGI2-synthesizing activities of cardiac tissue. Horse platelet and aorta microsomes were used as sources of thromboxane and prostacyclin synthetases respectively. The TXA2- and PGI2-synthesizing activities of cardiac tissue were studied on isolated perfused rabbit hearts (the heart microsomes being used both as TXA2 synthetase and PGI2 synthetase sources). TXB2 and 6-keto PGF1 alpha were determined by RIA. Among the compounds under study, 3-morpholino 4,6-diphenylpyridazine (III) was shown to inhibit specifically the TXA2 synthetase. Substitution of the morpholino group by a dimethylamino one (I) reinforced the inhibiting effects on TXA2 synthetase but it also revealed a slight anti-prostacyclin synthetase action of the molecule. Replacement of 3-morpholino moieties by either a 3-hydrazino (IV), or a 2-dimethylaminoethylamino (V), or a 2-morpholinoethylamino group (VI) abolished completely the effects of the molecule on TXA2 and PGI2 synthetases. Likewise the addition of chlorine on the para-position on the phenyl ring of I neutralized all its inhibitory effects both on TXA2 and PGI2 synthetases in vitro. None of the 3-amino 4,6-diarylpyridazine derivatives was active on either the TXA2- or PGI2-synthesizing activities of cardiac tissue.

Animals↗

Anticonvulsant activity of 3-oxo-5-substituted benzylidene-6-methyl-(4H)-2-pyridazinylacetamides and 2-pyridazinylacetylhydrazides.

A series of 3-oxo-5-substituted-benzylidene-6-methyl-(4H)-2- pyridazinylacetamides and 2-pyridazinylacetylhydrazides were synthesized and evaluated for anticonvulsant activity against electrically and chemically induced seizures. In the maximal electroshock-induced seizures test, most of the derivatives showed an anticonvulsant effect better than that of sodium valproate, a commonly used anticonvulsant drug. At 100 mg/kg orally, compounds 5a and 5b respectively protected 50 and 60% of the mice against pentylentetrazole-induced seizures. In addition, these two derivatives showed significant anticonvulsant properties at doses that did not produce ataxia or sedation. The title compounds were also tested for their ability to antagonize convulsions induced by bicuculline and strychnine. Their effect on tremors induced by oxotremorine in mice was also evaluated.

Acetamides↗

Synthesis and pharmacological evaluation of N-substituted 4,6-diaryl-3-pyridazinones as analgesic, antiinflammatory and antipyretic agents.

The synthesis and the pharmacological evaluation of 19 new 4,6-diaryl-3-pyridazinones are reported. All compounds were screened for analgesic, antiinflammatory and antipyretic activities. Introduction of an arylpiperazinomethyl moiety in the 2-position of the pyridazinone ring resulted in the most potent activities. Compounds 2a, 2b, 2h and 2i exhibited a higher analgesic activity than did aspirin or noramidopyrine in the hot plate test.

Analgesics↗

[Synthesis and antisecretory and anti-ulcer activity of new 4,6-diarylpyridazinones].

It has been possible to prepare from 4,6-diaryl pyridazinones a series of derivatives substituted in the 2-position and having urea moiety via the addition of free amines into methylisocyanate. Their gastric anti-secretory and anti-ulcer activities were evaluated. The compounds with an N-2 ethyl chain on the pyridazinone ring (IVa, IVd, IVg) were the most active derivatives.

Animals↗

[Synthesis and pharmacologic study of several spirohydantoins: relation to conformation].

Using two routes starting from cyclanones, it has been possible to prepare two series of spirohydantoins substituted or not on the hydantoin nucleus nitrogen. These compounds exhibited low toxicity on pig lens aldose reductase (except for two compounds). A discussion is given on the steric and geometric requirements for effective enzyme inhibiting activity.

Aldehyde Reductase↗

[Synthesis and pharmacologic evaluation of some dihydropyran carboxylic acids].

The synthesis of three new dihydropyran carboxylic acids has been performed by uncommon procedures: cyanosilylation, cyclisation of oxime. Their chemical structure was confirmed by I.R. and N.M.R. data. In a pharmacological evaluation they were found to possess significant effects on the passive cutaneous anaphylaxis test and on the central nervous system; one of them showed an interesting antiallergic effect whilst another showed an interesting sedative effect.

Analgesics↗

[Changes in plasma parameters in rabbit does as a function of their physiological state and feed rationing].

We followed the evolution of hematocrit and of plasma Na, K, Cl, total protein, creatinine, Pi, alkaline phosphatases, triglycerides, cholesterol, glucose and GPT. The amount of feed given to the rabbit does was restricted to 75 percent of the quantity eaten ad libitum, in similar conditions to those of intensive breeding. This had a slight effect on the values obtained for plasmatic components in healthy rabbits. This was not dependent on the timing of blood collection, nor on the physiological state of the animal. The changes in biochemical composition of the plasma due to pregnancy in healthy rabbit does are: a fall in total plasma protein and cholesterol levels, alkaline phosphatases activity, hematocrit, and a rise followed by a marked fall in plasma triglycerides level. During lactation, these levels return progressively to the values obtained in non-pregnant, non-lactating rabbits.

Alanine Transaminase↗

[The pathology of ther reproducing female rabbit: a comparative, descriptive study of morbidity phenomena observed during the reproduction o purebred strains of rabbit].

We analysed the working life of purebred New Zealand, and Californian rabbit breeding does kept in identical conditions. Our study notes the health of the does as well as various factors affecting the survival rate of baby rabbits until weaning. After the first six months of rearing the productivity and the health of the two breeds were very different. The Californian females came through their first two gestations and lactations very well but more than half of them showed signs of respiratory ailments, and many had to be eliminated. Their first two litters were characterised by a low number of baby rabbits weaned as well as a large number of whole litters dead before weaning. The females of the New Zealand breed were in good health but then died suddenly at the end of gestation or in the middle of lactation; the surviving females raised practically their whole litter until weaning. The loss of animals is numerically fairly similar in the two breeds but takes on different farms. This comparative study of the elimination of the does, of their mortality, or of that of the baby rabbits during lactation leads us to the hypothesis that these three phenomena are probably different manifestations of the same pathological phenomena occurring early on, probably from the first gestation onwards.

Animals↗

[Pathology among breeding does. Evolution of several plasma parameters among primiparous rabbit does].

One of the most important limiting factors of rabbit production is reproductive pathology. This pathology has two aspects: livestock reduction (elimination and death of rabbit does) and mortality of young rabbits before weaning. We studied alterations of hematocrit and of plasma Na, K, Ca, Mg, Pi, total proteins, prolactin, during gestation and lactation of primiparous rabbit does. In females which were going to die the first results showed a fall in plasma NaK, Ca concentrations and a rise in plasma Mg. We think that these alterations are only consequences of anterior metabolic alterations and are indicators or secondary causes of the animal's proximate death. We noticed a deep fall in plasma prolactin concentration before death; its signification is discussed. In the females which did not wean their whole litter, average prolacting levels during gestation and at the beginning of lactation were lower than in females weaning their whole litter. These first results would confirm the hypothesis that youngs' mortality is a pathology linked with dams' state.

Animal Diseases↗

[Attempt to induce diarrhea in young rabbits with different dietary crude fiber contents (author's transl)].

The influence of five diets containing 14.5, 10, 6.9, 4.6 and 3.3 per cent of crude fiber was studied in 6-week-old rabbits. Two additional groups of animals fed with the rations with 14.5, 6.9 and 3.3 per cent crude fiber were used. The first was inoculated with coccidia, the second was treated with ampicillin. In non-inoculated and untreated rabbits, diarrhea was inconstant, of short duration and low intensity and appeared only for cellulosis rate less than 4.6 per cent. There was no mortality. Decrease in the dietary crude fiber level cannot be considered as directly responsible for digestive ailments, when sanitary conditions are good. In our experimental conditions, it has been shown that a low level of cellulosis in the diet did not increase the pathological phenomena. Inversely pathogenic elements (coccidia) or medicaments used (ampicillin) can change the relations which exist between growth and components of the diet (cellulosis).

Animals↗