6-ketoprostaglandin-f1-alpha and beraprost

Prostacyclin (PGI2) is a bioactive substance produced by vascular endothelial cells, which exerts powerful vasodilative and anti-platelet actions. Patients with pulmonary hypertension have an imbalance between vasodilative PGI2 and vasoconstrictive thromboxane B2 (TXB2). Treatment with vasodilative agents is essential for such patients. Continuous intravenous infusion of PGI2 is an effective treatment of primary pulmonary hypertension in terms of exercise capacity and survival rate. We tested a new stable PGI2 analogue, beraprost sodium (Procyclin, Dornar) suitable for oral administration, in patients with primary and secondary pulmonary hypertension. A short-term study of cardiac catheterization in four patients with primary pulmonary hypertension showed a 15 +/- 12% reduction in mean pulmonary artery pressure in three of the four patients, and a 24 +/- 22% decrease in pulmonary vascular resistance in all four patients. Cardiac index increased by 27 +/- 14% in three of the four patients. Among three patients with secondary pulmonary hypertension, there was a 7% reduction in pulmonary artery pressure in one patient, and a 24 +/- 14% decrease in pulmonary vascular resistance in all three patients. In a long-term study (23 +/- 11 months), NYHA functional class improved from 3.0 +/- 0.7 to 2.4 +/- 0.5 in two of the five patients with primary pulmonary hypertension. Although the radiographic cardiothoracic ratio was not significantly improved, cardiac index increased by 78 +/- 60% in four of the five patients. Only two patients, one with primary and one with secondary pulmonary hypertension, died during the long-term follow-up period. Plasma TXB2/6-keto prostaglandin F1 alpha ratio decreased from 8.1 +/- 8.7 to 1.5 +/- 0.4. The optimal dose remains uncertain, but the initial dosage of 40-60 micrograms/day given in three to four doses for adult patients is considered to be acceptable. Side effects such as flushing face, headache, vomiting, and nausea were mild and resolved when the dose was reduced. Oral PGI2, beraprost, appears to be an effective and possibly adequate substitute for intravenous vasodilators in pulmonary hypertension for both short- and long-term management.

Topics: 6-Ketoprostaglandin F1 alpha; Administration, Oral; Adolescent; Adult; Child; Child, Preschool; Epoprostenol; Female; Humans; Hypertension, Pulmonary; Infant; Male; Middle Aged; Platelet Aggregation Inhibitors; Pulmonary Circulation; Pulmonary Wedge Pressure; Thromboxane B2; Time Factors; Vascular Resistance; Vasodilator Agents

Apoptosis is now widely recognized as an important part of chronic obstructive pulmonary disease (COPD) pathogenesis. Our previous study demonstrated that a prostacyclin (PGI(2)) analogue (beraprost sodium, BPS) prevented cigarette smoke extract (CSE) induced apoptosis of the pulmonary endothelium in rats. So we determined to clarify the apoptosis of vascular endothelial cells in COPD patient and the role of prostacyclin in the protection against apoptosis in vascular endothelial cells induced by CSE. Surgical specimens were obtained from 12 patients with COPD and 10 controls, and the level of apoptosis, prostacyclin synthase (PGI(2)S) expression and 6-keto-PGF1α (a stable metabolite of PGI(2)) were detected. The apoptotic index (AI), caspase-3 activity, expression of caspase-3 and 6-keto-PGF1α were examined in human umbilical vein endothelial cells (HUVECs) under exposure to varied concentrations of CSE for 24 h as well as under exposure to 2.5 % CSE for varied durations. Then, HUVECs under 2.5 % CSE were exposed to varied concentrations of BPS for 24 h and observed the alteration and the level of cAMP. Increased AI, decreased expression of PGI(2)S and 6-keto-PGF1α, were found in the lungs of patients with COPD compared with controls. Moreover, CSE induced apoptosis in means of both dose-dependent and time-dependent manners, and reduced the level of 6-keto-PGF1α in HUVECs. And with the treatment of BPS, an enhanced level of cAMP and decreased apoptosis were detected. The deficiency of PGI(2) critically contributes to the COPD-associated endothelial dysfunction and apoptosis. And BPS protects against the apoptosis in the vascular endothelial cells induced by CSE.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Apoptosis; Case-Control Studies; Caspase 3; Cyclic AMP; Cytochrome P-450 Enzyme System; Dose-Response Relationship, Drug; Endothelial Cells; Epoprostenol; Female; Human Umbilical Vein Endothelial Cells; Humans; Immunohistochemistry; In Situ Nick-End Labeling; Intramolecular Oxidoreductases; Lung; Male; Middle Aged; Pulmonary Disease, Chronic Obstructive; Rats; Smoking; Time Factors

Chronic inflammation, imbalance of proteolytic and anti-proteolytic activities, oxidative stress, and apoptosis of lung structural cells contribute to the pathogenesis of COPD. Prostacyclin protects cells against apoptosis, has anti-inflammatory properties, partially prevents cigarette smoke extract (CSE)-induced apoptosis of the pulmonary endothelium, and thus may be relevant in the pathogenesis of emphysema. We determined whether a synthetic stable prostacyclin analog, beraprost sodium (BPS), attenuates the development of CSE-induced emphysema and elucidated the molecular mechanisms involved in its effect. Sprague-Dawley rats were treated with BPS and injected with CSE once a week for 3 wk. We measured the DNA damage of cells, the expression of caspase-3, and the activity of matrix metalloproteinase (MMP)-2 and MMP-9. We also analyzed TNFalpha and IL-1beta concentrations and the serum antioxidant activity. BPS prevented the development of CSE-induced emphysema, resulting in significant attenuation in alveolar enlargement and pulmonary parenchymal destruction. BPS inhibited pulmonary apoptosis and induction of MMP-2 and MMP-9 activity. Moreover, the protective effect of BPS was associated with a reduction of the expression of proinflammatory cytokines including TNFalpha and IL-1beta and a normalized biological oxidant activity. BPS introduces all these events, probably by activating cAMP signaling through acting specific prostacyclin receptors. In conclusion, BPS protects against the development of CSE-induced emphysema by attenuating apoptosis, inhibiting proteolytic enzyme activity, reducing inflammatory cytokine levels, and augmenting antioxidant activity. BPS may potentially represent a new therapeutic option in the prevention of emphysema in humans in prospect.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Antioxidants; Apoptosis; Caspase 3; Cyclic AMP; Cytokines; Enzyme Activation; Epithelial Cells; Epoprostenol; In Situ Nick-End Labeling; Lung; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Pneumonia; Protective Agents; Pulmonary Emphysema; Rats; Rats, Sprague-Dawley; Smoking

The effects of H(2)O(2) on the membrane potential of smooth muscle cells of rabbit mesenteric resistance arteries were investigated. H(2)O(2) (3-30 microM) concentration-dependently hyperpolarized the membrane; this was inhibited by catalase but not by superoxide dismutase or the hydroxyl-radical scavenger dimethylthiourea. The cyclooxygenase inhibitor diclofenac partly inhibited the responses; the subsequent addition of the 5-lipoxygenase inhibitor 2-(12-hydroxydodeca-5,10-diynyl)-3,5,6-trimethyl-p-benzoquinone (AA-861) (but not the cytochrome P(450) inhibitor 17-octadecynoic acid) further attenuated H(2)O(2)-induced hyperpolarizations. The sarcolemmal ATP-sensitive K(+) (K(ATP)) channel inhibitor 1-[5-[2-(5-chloro-o-anisamido)ethyl]-2-methoxyphenylsulfonyl]-3-methylthiourea, sodium salt (HMR-1098), blocked the H(2)O(2)-induced hyperpolarization in the absence and presence of diclofenac. H(2)O(2) increased the production of prostaglandin E(2) and prostacyclin (estimated from its stable metabolite 6-keto-prostaglandin F(1alpha)), both of which produce a HMR-1098-sensitive hyperpolarization in the smooth muscle cells. It is concluded that, in smooth muscle cells of rabbit mesenteric artery, H(2)O(2) increases the synthesis of vasodilator prostaglandins and possibly 5-lipoxygenase products, which produce a hyperpolarization by activating sarcolemmal K(ATP) channels.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Benzoquinones; Cyclooxygenase Inhibitors; Diclofenac; Dinoprostone; Dose-Response Relationship, Drug; Epoprostenol; Hydrogen Peroxide; In Vitro Techniques; Leukotriene C4; Leukotriene D4; Lipoxygenase Inhibitors; Male; Membrane Potentials; Mesenteric Arteries; Muscle, Smooth, Vascular; Nitroprusside; Potassium Channel Blockers; Rabbits; Vasodilator Agents

We investigated the effects of low-dose Beraprost sodium (BPS), a stable prostaglandin I2 (PGI2) analogue, on microvascular permeability and the plasma concentrations of thromboxane and adenosine 3',5'-cyclic monophosphate (cAMP) in blood-perfused rabbit lungs subjected to ischemia-reperfusion (I/R). After an ischemic insult for 2 h, saline as a vehicle, 3 pmol/L of BPS (BPS-1), 150 to 300 pmol/L of BPS (BPS-2), 900 pmol/L of BPS (BPS-3), or 60 micromol/L of indomethacin (IND) was administered into the reservoir, then the lungs were reperfused and reventilated for 1 h. Vascular permeability was assessed by determining the microvascular filtration coefficient (Kf, ml/min/mm Hg/100 g wet lung). I/R resulted in increases in vascular resistance, Kf, and thromboxane. BPS-2, BPS-3, and IND inhibited the increase in vascular resistance, and BPS-3 and IND attenuated the increases in Kf and thromboxane. BPS-3 increased, but IND decreased, the concentrations of cAMP in the perfusate. Perfusate thromboxane released after reperfusion was significantly correlated with Kf. We conclude that cyclooxygenase products play a critical role in I/R-induced lung vascular injury and that 900 pmol/L of BPS inhibits the production of thromboxane and enhances the permeability barrier via a cAMP-elevating effect. However, vasodilatory action of BPS may exacerbate the reperfused lung injury by increasing the flow through injured capillaries via inhibition of thromboxane-induced vasoconstriction.

Topics: 6-Ketoprostaglandin F1 alpha; Analysis of Variance; Animals; Anti-Inflammatory Agents; Anti-Inflammatory Agents, Non-Steroidal; Blood Pressure; Capillaries; Capillary Permeability; Cyclic AMP; Epoprostenol; Indomethacin; Lung; Lung Diseases; Male; Microcirculation; Rabbits; Reperfusion Injury; Respiration, Artificial; Thromboxane B2; Tumor Necrosis Factor-alpha; Vascular Resistance; Vasodilation; Vasodilator Agents

Cardiac fibroblasts, as the source of extracellular matrix for the left ventricle, subserve important functions to cardiac remodeling and fibrotic development following myocardial infarction or with pressure-overload cardiac hypertrophy. The fibroblast may be the target cell for angiotensin-converting enzyme inhibitors (ACEI) that are cardioprotective and reverse collagen deposition and remodeling but whose mechanisms of action remain controversial. Because we previously documented phenotypic differences between cardiac fibroblasts from the spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) left ventricle, the present study evaluated whether phenotypic differences also exist in the release of endogenous arachidonic acid metabolites or in the activation of phospholipase D, and the importance of observed differences to the formation of collagen and the mechanism of action of ACEI. The experimental design compared endogenous sources of arachidonic acid with exogenous prelabeling of cells. Angiotensin II stimulated greater arachidonic acid release than bradykinin, and WKY cells were more responsive than SHR. The major prostanoid formed by cardiac fibroblasts was prostaglandin I2 (PGI2), with more prostacyclin production by WKY cells than SHR cells both under nonstimulated conditions and in response to angiotensin II or bradykinin. Beraprost, a PGI2 analogue, was shown to decrease growth rate and DNA synthesis of fibroblasts and to inhibit mRNA expression for collagen types I and III, with SHR cells being less responsive to beraprost than WKY cells. These results potentially implicate eicosanoid metabolism, particularly PGI2, in collagen formation, fibrotic development, and cardiac remodeling, and they imply that the SHR genetic hypertension model may be predisposed to excess cardiac fibrosis.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Arachidonic Acid; Cell Division; Chromatography, High Pressure Liquid; Collagen; Epoprostenol; Extracellular Matrix Proteins; Gene Expression; Glycerophospholipids; Male; Myocardium; Phosphatidic Acids; Rats; Rats, Inbred SHR; Rats, Inbred WKY

The effect of a prostacyclin analog, beraprost sodium, on the electroretinogram, motor nerve conduction velocity, and nerve blood flow was determined in rats with streptozotocin-induced diabetes and was compared with the effect of insulin. Beraprost sodium (0.01 mg x kg-1 x day-1 for 8 weeks) significantly shortened the peak latency of the electroretinogram b-wave, increased tail nerve conduction velocity, and increased sciatic nerve blood flow in diabetic rats (P < 0.0003, 0.0001, and 0.0001 vs. untreated diabetic rats, respectively). This was accompanied by a significant increase in the 6-keto-prostaglandin F1alpha content of the thoracic aorta and a marked increase in the cAMP content of the sciatic nerve. Beraprost sodium had no effect on the sorbitol and fructose contents of the sciatic nerve and retina, but insulin (8-10 U/day) significantly reduced both parameters. These findings suggest that beraprost sodium may be useful for prevention of vascular and neural dysfunction in the retina and peripheral nerve.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Aorta, Thoracic; Cyclic AMP; Diabetes Mellitus, Experimental; Diabetic Neuropathies; Diabetic Retinopathy; Electroretinography; Epoprostenol; Insulin; Male; Neural Conduction; Rats; Rats, Wistar; Retina; Sciatic Nerve