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Biomedical subjects

J Damas

Publications and source records attributed to J Damas.

At least 145 records · Page 8Linked to original sources
PubMed1980

[Cardiovascular responses of the rat to a prostaglandin endoperoxide analog].

In the anaesthetized rat, injection of the prostaglandin endoperoxide analog, U 44069, in the right ventricle is vasopressor both in the pulmonary and the systemic circulation. When a moderate dose is used, the hypertensive response of the systemic vascular bed changes in an hypotension. The toxicity seems to be cumulative. At high doses, a vascular collapse is observed sometimes with pulmonary oedema. These findings correlate with the EKG pattern typical for an acute cor pulmonale.

Animals↗
PubMed1980

[Radioimmunoassay of low molecular weight human kininogen].

A radioimmunoassay for low molecular weight (LMW) human Kininogen has been carried out. The first step was to prepare LMW Kininogen from human plasma. The proposed method allowed to get chemically pure and biologically active LMW Kininogen. This preparation was used to induce antibody. Optimal conditions for labelling and incubation were determined. This method may be applied to the assay of Kininogen in human plasma.

Humans↗
PubMed1980

[Platelet stimulation in rats by lambda carrageenan and fibrinogen].

Defibrinogenation by defibrase does not modify the hypotensive activity of lambda carrageenan in the Brown Norway rat. Defibrinogenation by defibrase and kininogen depletion by ellagic acid do not change this activity in the Wistar rat. This hypotensive action of lambda carrageenan which depends on platelet stimulation, is unaffected by the lack of fibrinogen.

Animals↗
PubMed1980

[Kinins-formation, hypotensive and oedematogen activities of four carrageenans (author's transl)].

1) The abilities of four carrageenans to form kinins in the rat plasma "in vitro" have been compared. Three carrageenans were pure: iota, kappa and lambda. The fourth sample was a mixture, made mostly of the iota type, that we called iota 2. The order of activity at the threshold level is: iota 1 = iota 2 greater than lambda greater than kappa. Kinin-formation by carrageenans is inhibited by hexadimethrine which suggests that kinin-formation depends on the activation of the Hageman factor. 2) The scale of the relative potencies of the same compounds to induce threshold hypotension when administered intravenously is the same as that for kinin-formation "in vitro". This effect is also inhibited by hexadimetrine. Crossed tachyphylaxies show that the lambda carrageenan is the most active in that respect. On this basis the order of potency is:lambda greater than iota 2 = iota 1 greater than kappa. 3) The ability to produce oedema is in the following order: lambda greater than or equal to iota 2 = iota 1 greater than kappa. The identity of the last two scales would indicate that the kinin system is of greater importance in the inflammatory process induced by carrageenans.

Animals↗
PubMed1980

[Anaphylactic shock in brown Norway rats with reagins and no precipitins in the blood (author's transl)].

Brown Norway rats have been actively sensitized against hen ovalbumine mixed with anti Bordella pertussis vaccine. After ten to twelve days, IgE are detected in the blood, but no precipitins. Anaphylactic shock induced by i.v. injection of 1 mg.100 g-1 body weight of ovalbumine is caracterized by a vascular collapse, the animal dying in about 15 minutes. This collapse is identical with the same general anaphylactic reaction as observed in the Wistar rats, which have large amounts of precipitins in the blood.

Anaphylaxis↗
PubMed1979

[Inhibition of carrageenan edema by carrageenan itself].

The influence of two kinin forming agents: iota carrageenan and ellagic acid, on the paw oedema induced by 48/80, an amino-liberator, or by carrageenan iota, has been studied, in the Rat. Ellagic acid and carrageenan, by intraperitoneal injection, reduce the paw oedema induced respectively by 48/80 and carrageenan itself. This inhibition depends on a non-specific "counter-irritation" and not on kininogen stores depletion. Ellagic acid, by intravenous injection, diminishes the oedema induced by carrageenan; swelling due to 48/80, is not affected. So kininogen activation plays some role in the inflammatory processes induced by iota carrageenan. Carrageenan by intravenous injection, suppresses his own inflammatory action but does not influence at all the similar action of 48/80. The anti-inflammatory effect of carrageenan does not exclusively depend on kininogen stores depletion.

Animals↗
PubMed1979

[Role of platelets in arterial hypotension induced by arachidonic acid and in carrageenan induced edema in the rat].

When rat platelets are incubated in vitro in the presence of aspirin, the formation of malonaldehyde from arachidonic acid is inhibited. The production of malonaldehyde reflects the synthesis of prostaglandins and associated compounds. The same inhibition is found when the platelets originate from rats pretreated with aspirin. Small doses of aspirin are active in vitro and 10-20 mg/kg in vivo. This dosage of aspirin does not affect the hypotensive activity of arachidonic acid nor the oedematous properties of carrageenan in the rat. These two effects are thus independent from the prostaglandins formed in the platelets.

Arachidonic Acids↗
PubMed1979

[Effect of oxamethacin and sulindac on prostaglandin synthesis].

1. Indomethacin and oxamethacin reduce the formation of malonaldehyde from arachidonic acid by rat platelets in vitro. Sulindac has no influence on this formation. 2. Indomethacin, oxamethacin and sulindac inhibit the action of arachidonic acid on the rat stomach strips in vitro. 3. These three anti-inflammatory drugs suppress the hypotensive activity of arachidonic acid in the rat in vivo. 4. The comparison of the inhibitory activities of these drugs in vivo and in vitro shows that sulindac is converted to a potent anti-prostaglandin-synthetase metabolite and that a part of the action of oxamethacin depends on its conversion to indomethacin in the rat.

Animals↗
PubMed1978

[Hypotensive and edematogenic effects of carrageenan in the irradiated rat].

Iota carrageenan induces the same hypotensive effect in leucopenic and thrombopenic rats as in normal animals. This hypotensive activity depends on kininogen-kinins activation. In the irradiated rats, the inflammatory response to iota carrageenan is reduced. The blood cells are thus responsible of the major part of the late inflammatory effect. There is non parallelism between this hypotensive and the oedematogen activities of iota carrageenan in the rat.

Animals↗