Systemic synthesis of prostaglandin I2 following …

Effects of prostacyclin (PGX) on cyclic AMP concentrations in human platelets.

and prostaglandin I2 is abbreviated PGI2 ..

N2 - Whereas numerous studies have investigated the role of prostacyclin and thromboxane A2 in the maintenance of coronary blood flow, most of these have focused on normal vessels. In the present investigation, we examined the prostaglandin- and thromboxane-synthesizing capacity of isolated coronary artery segments obtained from the site of a critical coronary artery stenosis. Cyclic flow variations were produced by placing a hard cylindrical constrictor on the proximal left anterior descending coronary artery in open-chest, anesthetized dogs. Cyclic flow variations are characterized by progressive declines in coronary blood flow, interrupted by sudden spontaneous restorations of flow. After cyclic flow variations had been induced, the hearts were removed, and the left anterior descending and circumflex coronary arteries were dissected. The vessels were cut into segments and incubated in the presence of increasing concentrations of arachidonic acid (10-4-10-6 M). The synthesis of prostaglandin E2, thromboxane B2, and 6-keto prostaglandin F(1α) by the coronary segments was measured by radioimmunoassay. When incubated in the presence of 10-5 M arachidonic acid, coronary artery segments obtained from the left anterior descending coronary artery undergoing cyclic flow variations produced substantially more thromboxane B2 (142 ± 27 vs 29 ± 3 pg/mg P

Synthesis of Vane's prostaglandin X, 6,9alpha-oxido9alpha,15alpha-dihydroxyprosta-(Z)5,(E)13-dienoic acid.

Synthesis of prostaglandin I2 ..

N2 - The metabolic responses of equine articular cartilage to incubation with bacterial lipopolysaccharide (LPS) were studied, using explant cultures of articular cartilage obtained from the metatarsophalangeal joints of 15 horses, age of which ranged from 3 months to 20 years. For comparison, explants were also established from the metatarsophalangeal joints of 3 calves. Explants were cultured for 3 days in medium containing various concentrations of LPS from 0 (control) to 100 micrograms/ml. Glycosaminoglycan (GAG) released during the 3-day incubation was determined by a spectrophotometric assay, using the dye 1,9-dimethylmethylene blue. Newly synthesized GAG content was assayed by measuring [35S]sulfate incorporation during a 3-hour pulse labeling period. In addition, prostaglandin E2 (PGE2) synthesis was quantified, using a [3H]PGE2 radioimmunoassay kit and magnetic separation. Finally, explants from 3 animals were used to evaluate the effect of supplementing culture medium with 5% serum on the response of explants to LPS, and explants from 1 horse were used to compare responses to stimulation with LPS derived from 2 bacterial sources. Equine explants cultured with bacterial LPS had a dose-dependent decrease in synthesis and increase in release of GAG, and these responses were significantly (P

Synthesis and biological properties of a 9,11-azo-prostanoid: highly active biochemical mimic of prostaglandin endoperoxides.

AB - The metabolic responses of equine articular cartilage to incubation with bacterial lipopolysaccharide (LPS) were studied, using explant cultures of articular cartilage obtained from the metatarsophalangeal joints of 15 horses, age of which ranged from 3 months to 20 years. For comparison, explants were also established from the metatarsophalangeal joints of 3 calves. Explants were cultured for 3 days in medium containing various concentrations of LPS from 0 (control) to 100 micrograms/ml. Glycosaminoglycan (GAG) released during the 3-day incubation was determined by a spectrophotometric assay, using the dye 1,9-dimethylmethylene blue. Newly synthesized GAG content was assayed by measuring [35S]sulfate incorporation during a 3-hour pulse labeling period. In addition, prostaglandin E2 (PGE2) synthesis was quantified, using a [3H]PGE2 radioimmunoassay kit and magnetic separation. Finally, explants from 3 animals were used to evaluate the effect of supplementing culture medium with 5% serum on the response of explants to LPS, and explants from 1 horse were used to compare responses to stimulation with LPS derived from 2 bacterial sources. Equine explants cultured with bacterial LPS had a dose-dependent decrease in synthesis and increase in release of GAG, and these responses were significantly (P


SYSTEMIC PROSTAGLANDIN I2 SYNTHESIS IS NORMAL …

AB - Osteoarthritis is characterized by inflammation and increased production of pro-inflammatory mediators including cytokines and prostaglandin E2 (PGE2). Macrophage-like cells in synovial tissue produce these mediators which induce degradative enzymes that break down cartilage. We determined whether avocado/soybean unsaponifiables (ASU) and chondroitin sulfate (CS) can inhibit cytokine expression and PGE2 production using monocyte/macrophage-like cell models. Cells were incubated for 24 hours with either control media alone, ASU alone (NMX1000; 8.3 μg/ml), CS alone (TRH122; 20 μg/ml), or a combination of both preparations. Cells were activated with cytokines or lipopolysaccharide for 1 or 24 hours to determine cytokine gene expression by RT-PCR and PGE2 production by immunoassay, respectively. In response to activation, THP-1 cells exhibited increased expression of TNF-α and IL-1β, while RAW cells increased synthesis of PGE2. Cytokine expression and PGE2 synthesis were significantly decreased by the combination of ASU and CS compared to the individual treatments alone (P

Another pathway involves PGI2 oxidation to 15-oxo-prostaglandin I2 ..

The inhibitor, which is ether extractable, has been identified using a two-step thin-layer radiochromatographic procedure and a synthetic prostaglandin I2 standard.

Synthesis of prostaglandins in cholera toxin-treated Chinese ..

N2 - Osteoarthritis is characterized by inflammation and increased production of pro-inflammatory mediators including cytokines and prostaglandin E2 (PGE2). Macrophage-like cells in synovial tissue produce these mediators which induce degradative enzymes that break down cartilage. We determined whether avocado/soybean unsaponifiables (ASU) and chondroitin sulfate (CS) can inhibit cytokine expression and PGE2 production using monocyte/macrophage-like cell models. Cells were incubated for 24 hours with either control media alone, ASU alone (NMX1000; 8.3 μg/ml), CS alone (TRH122; 20 μg/ml), or a combination of both preparations. Cells were activated with cytokines or lipopolysaccharide for 1 or 24 hours to determine cytokine gene expression by RT-PCR and PGE2 production by immunoassay, respectively. In response to activation, THP-1 cells exhibited increased expression of TNF-α and IL-1β, while RAW cells increased synthesis of PGE2. Cytokine expression and PGE2 synthesis were significantly decreased by the combination of ASU and CS compared to the individual treatments alone (P