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Biomedical subjects

F Russo-Marie

Publications and source records attributed to F Russo-Marie.

At least 109 records · Page 6Linked to original sources
PubMed1985

[Physiology of the interactions of blood and the blood vessel wall. Role of pharmacologically active lipids].

The interactions of blood cells (platelets and leukocytes) with the components of the vessel wall (endothelial cells, extracellular subendothelial matrix and smooth muscle cells) play an important role in the initiation of thrombosis and the development of atherosclerosis. These cellular interactions are partially regulated by the formation of pharmacologically active lipids (PAL): prostaglandins, leukotrienes, PAF-acether and related compounds. These biochemical mediators are produced from the phospholipids of the cell membrane in response to external stimulation. The metabolic precursors, such as arachidonic acid, are common. The subsequent enzymatic differentiation leads to the formation of different terminal products according to the cells, thromboxane A2 in the platelets and prostacyclin in the endothelial cells.

Arachidonic Acids↗
PubMed1984

Affinity of tixocortol pivalate (JO 1016), tixocortol, cortisol acetate and cortisol for dexamethasone receptors of mouse thymus cells and rat renomedullary interstitial cells in culture. Correlation with their biological activities.

Affinity for the dexamethasone binding sites of tixocortol pivalate, (the ester of the 21 thiol derivatives of cortisol), a steroid with local anti-inflammatory activity similar to cortisol acetate and with no systemic activity, was investigated in comparison with other steroids: tixocortol (the thiol derivative yielded by esterase hydrolysis), cortisol acetate and cortisol. The rank order of relative affinity for dexamethasone receptor of mouse thymocytes (37 degrees C) was: dexamethasone (1), cortisol (0.20), tixocortol pivalate (0.16), tixocortol (0.065), cortisol acetate (0.05). The corresponding 21 oxygenated ester (cortisol pivalate) was found less potent (0.080). Using rat renomedullary interstitial cells in culture, tixocortol pivalate showed also a higher receptor affinity than tixocortol. Cortisol acetate was as potent as tixocortol pivalate. The biological activity of tixocortol pivalate measured by the inhibition of PGE2 secretion on the same model, was similar to cortisol acetate and cortisol (10(-6) M, 24 h incubation, 38-55% inhibition). Tixocortol was less active (26%). These results with tixocortol pivalate are in good agreement with previously reported in vivo studies and show a good correlation between its binding ability and biological effect.

Animals↗
PubMed1984

Novel concepts in the mode of action of anti-inflammatory steroids.

Since the discovery that cortisone could be used as an anti-inflammatory agent, this compound and synthetic anti-inflammatory steroids have been widely used in all inflammatory and allergic diseases. Anti-inflammatory steroids have been reported to act on almost all steps of the inflammatory reaction. Nevertheless their molecular mechanism of action has remained poorly understood, in opposition to non steroidal anti-inflammatory drugs whose mechanism is now well known. We report here recent data concerning their molecular mechanism of action. These recent results have all led to the conclusion that part of their action can be explained by the synthesis "de novo" of one or more proteins which then will inhibit the deacylation of arachidonic acid from membrane phospholipids. Whether the action of this or these proteins can explain all the known anti-inflammatory actions of steroids remains to be investigated.

Adrenal Cortex Hormones↗
PubMed1983

Further characterization of the glucocorticoid-induced antiphospholipase protein "renocortin".

The steroid-induced anti-phospholipase protein "Renocortin" has been further characterized by column chromatography and a monoclonal antibody. In medium devoid of foetal calf serum, renomedullary insterstitial cells in culture exposed to the anti-inflammatory steroid dexamethasone released 3 peptides of apparent MW: 15k, 30k, and 45k possessing similar biological properties to "renocortin", "lipomodulin" and "macrocortin". A monoclonal antibody directed against macrocortin also bound the 45k peptide released from the renomedullary cells. The 15k species was, like macrocortin, inactive in an "in vitro" enzymatic assay but recovered its full inhibitory activity after dephosphorylation by alkaline phosphatase treatment. We conclude that "macrocortin", "lipomodulin" and "renocortin" are similar if not identical proteins. We propose a scheme to account for "in vivo" secretion and regulation of these proteins.

Animals↗
PubMed1983

Angiotensin II does not elicit any specific prostaglandin secretion in piglet cultured endothelial cells.

PGE2 and PGF2 alpha were measured in culture media from piglet aortic endothelial cells by radioimmunological analysis. Prostacyclin secretion was evaluated by radioimmunological analysis of its stable metabolite, 6-keto-PGF1 alpha after reverse-phase high pressure liquid chromatography separation. No stimulation of either prostaglandin was detectable in culture media after treatment with angiotensin II (10(-9) to 10(-6) M) for 15 to 120 min at 37 degrees C. Under the same conditions angiotensin II (10(-7) M) elicited a 2 to 3 fold increase in PGE2 and PGF2 alpha secretion when incubated with cultured piglet aortic smooth muscle cells. In addition, we failed to detect specific angiotensin receptors at the surface of intact cultured endothelial cells. Since there was a very rapid increase in prostaglandin secretion after washing or medium changes we suggested that the effects of Angiotensin II on prostacyclin production, demonstrated in perfused organs, could be due to the mechanical stimulation elicited by the contraction of the underlying smooth muscle cells.

6-Ketoprostaglandin F1 alpha↗
PubMed1983

Differential effects of sex steroids on prostaglandin secretion by male and female cultured piglet endothelial cells.

The effect of sex steroids, 17 beta-estradiol and testosterone, on the production of 6-keto-prostaglandin F1 alpha, prostaglandin F2 alpha and prostaglandin E2 was studied in cultures of piglet aorta endothelial cells. In cells isolated from female animals both steroids stimulated the secretion of prostaglandins. In contrast, sex steroids did not affect prostaglandin synthesis by endothelial cells taken from male animals. In addition, female endothelial cells convert testosterone into estriol, estrone and estradiol. Estradiol-induced stimulation of prostacyclin production may explain in part the beneficial role generally attributed to naturally occurring estrogens in cardiovascular diseases.

6-Ketoprostaglandin F1 alpha↗
PubMed1983

Characterization and partial purification of 'renocortins': two polypeptides formed in renal cells causing the anti-phospholipase-like action of glucocorticoids.

1 Anti-inflammatory steroids reduce prostaglandin E2 (PGE2) synthesis in rat renomedullary interstitial cells in culture by inhibiting the release of arachidonic acid from membranous phospholipid stores, exhibiting antiphospholipase-like properties. 2 After treatment of the cells with dexamethasone 10(-6)M, these cells release a protein in the supernatant. 3 This supernatant is able to inhibit PGE2 secretion in untreated cells and to inhibit phospholipase A2 activity in an in vitro system. 4 Using chromatofocusing separation, we showed that two distinct proteins exist with isoelectric points of 5.8 and 8.3. 5 Using gel permeation separation, we showed that two proteins exist with apparent molecular weights of 15,000 and 30,000 daltons. 6 We conclude that, in renal cells in culture, anti-inflammatory steroids induce the synthesis and the release of two polypeptides which we have named 'Renocortins' (induced by corticoids in renal cells) causing the antiphospholipase-like action of glucocorticoids. 7 Our results are in good agreement with others, but as renal cells are not directly involved in the inflammatory process, we suggest that this steroid-induced phenomenon is not solely involved in the inflammatory reaction but is of more general physiological relevance.

Animals↗
PubMed1983

[Cellular mechanism of action of molsidomine. Bioinduction of prostacyclin].

Prostacyclin belongs to the family of prostaglandins, which are derived from arachidonic acid. It is secreted by vascular endothelium and possesses vasodilator and platelet anti-aggregant properties. This paper shows that molsidomine, a new anti-angina agent with vasodilator effects, is able to induce the secretion of prostacyclin by vascular endothelial cells in the aorta of the piglet. Molsidomine, via its stable metabolite SIN 1, induces very rapid and early secretion of prostacyclin followed by a refractory effect on vascular endothelium. At the same time, SIN 1 inhibits the platelet synthesis of thromboxane A2, which suggests that part of the action of molsidomine is related to an improvement in the prostacyclin/thromboxane A2 equilibrium, which has been shown to be disturbed in the course of certain cardiovascular diseases.

6-Ketoprostaglandin F1 alpha↗
PubMed1982

6-Ketoprostaglandin F1 alpha, prostaglandins E2, F2 alpha and thromboxane B2 production by endothelial cells, smooth muscle cells and fibroblasts cultured from piglet aorta.

After [3H]arachidonic acid labeling, cyclooxygenase products were qualitatively analysed in the media of each cultured vascular cell type by reverse-phase high-performance liquid chromatography (rp-HPLC). The prostaglandin E2, prostaglandin F2 alpha, 6-ketoprostaglandin F1 alpha and thromboxane B2 detected in the rp-HPLC radioactive profile were then quantified by radioimmunoassay (RIA) in separate sets of experiments. In preconfluent endothelial cells prostaglandin F2 alpha and 6-ketoprostaglandin F1 alpha were detected in equal amounts (49%), whereas after confluence 6-ketoprostaglandin F1 alpha represented 57% of total secretion (P less than 0.05). Smooth muscle cells secreted mainly prostaglandin F2 alpha (48%) and fibroblasts prostaglandin E2 (44%). Using the bioassay method, antiaggregatory activity was detected only in endothelial cells, though a small percentage of immunoreactive 6-ketoprostaglandin F1 alpha was encountered in smooth muscle cells and fibroblasts (13 and 10%, respectively). Radioimmunological analysis after rp-HPLC separation of the medium of endothelial cells showed that the anti-6-ketoprostaglandin F1 alpha antibody recognized, among other substances, an unidentified compound. Its retention time was similar to that of prostaglandin F2 alpha. This unidentified compound was not detected in the media from smooth muscle cells and fibroblasts.

6-Ketoprostaglandin F1 alpha↗
PubMed1982

Dexamethasone-induced inhibition of prostaglandin production dose not result from a direct action on phospholipase activities but is mediated through a steroid-inducible factor.

Investigations were carried out to define the mechanisms of steroid-induced inhibition of prostaglandin secretion by rat renomedullary cells in tissue culture. Although it was strongly proposed that glucocorticoids may inhibit phospholipase A2 activity, we present several pieces of evidence against a direct action of dexamethasone on phospholipase activities. First, dexamethasone, which significantly decreases the release of labeled material from cells prelabeled with [3H]arachidonate, does not significantly alter the pattern of distribution of the radioactivity among the various classes of cell lipids. In addition, direct measurement of phospholipase A3 activity in dexamethasone-treated cells failed to show any significant decrease in the deacylation capacity. On the other hand, several indications suggest that dexamethasone may induce the secretion of a non-dialysable, transferable factor able to inhibit prostaglandin production, the mechanism of which remains to be investigated.

Animals↗
PubMed1982

Glaphenine-induced acute renal failure in the rat: a new experimental model.

Glaphenine, a nonsteroid analgesic compound, administered by gastric gavage in rats (800 mg/kg), induced nonoliguric reversible acute renal failure (ARF). Intratubular deposits were found in medullary collecting ducts. Intratubular hydrostatic pressure (Pt) increased from 11.7 +/- 0.7 to 30.0 +/- 0.9 mmHg. Renal failure was almost completely prevented by concomitant high water and solute diuresis, achieved by furosemide infusion in Wistar rats and by high salt intake in Brattleboro rats with diabetes insipidus. In the latter protected animals, Pt was only slightly elevated (17.0 +/- 0.5 mmHg). Urinary excretion of prostaglandin E2 (PGE2) dropped dramatically after glaphenine administration in Wistar rats; the fall was slight in Brattleboro rats in which PGE2 excretion was normally low. We conclude that tubular obstruction plays a prominent role in glaphenine-induced ARF in the rat. High water and solute diuresis prevented tubular obstruction. Reduced renal PGE2 synthesis is probably not involved in the pathophysiology of this ARF model, inasmuch as Brattleboro rats on a high salt intake were protected despite low basal urinary excretion of PGE2.

Acute Kidney Injury↗