adrenomedullin and beraprost

This review assesses the available evidence supporting the use of drug combinations for the management of the various forms of pulmonary arterial hypertension (PAH). Ongoing and forthcoming randomized trials evaluating this strategy are also highlighted. Furthermore, new types of agents to treat PAH in the future are explored.

Topics: Adrenomedullin; Angiopoietin-1; Antihypertensive Agents; Benzamides; Bosentan; Drug Therapy, Combination; Eicosanoids; Epoprostenol; Genetic Therapy; Humans; Hypertension, Pulmonary; Imatinib Mesylate; Intracellular Signaling Peptides and Proteins; Piperazines; Platelet Aggregation Inhibitors; Prostaglandins; Protein Serine-Threonine Kinases; Purines; Pyrimidines; rho-Associated Kinases; Serotonin; Serotonin Plasma Membrane Transport Proteins; Sildenafil Citrate; Sulfonamides; Sulfones; Vasoactive Intestinal Peptide; Vasodilator Agents

This study investigated whether plasma levels of adrenomedullin, a potent vasodilating endogenous neurohumoral mediator, are useful for assessing the severity of primary pulmonary hypertension.. Seventeen pediatric patients with primary pulmonary hypertension (eight girls, nine boys, mean age 12 +/- 4 years) were enrolled in this study. Thirteen patients in New York Heart Association (NYHA) classes III and IV had been treated with long-term continuous intravenous prostacyclin (PGI2) infusion therapy, and four patients in classes I and II had received beraprost sodium, an oral PGI2 analogue. Blood samples were taken from all patients at the first visit. Plasma levels of atrial and brain natriuretic peptide (ANP, BNP) and endothelin-1, and mature-type adrenomedullin were measured. The relationships were investigated between neurohumoral mediator levels and NYHA class, pulmonary hemodynamics, and exercise capacity assessed by 6-minute walk test. The changes in neurohumoral mediator levels at 1 month, 3 months, and 6 to 12 months were also evaluated in 11 survivors with long-term PGI2 treatment.. All neurohumoral mediator levels were positively correlated with severity of NYHA class. Patients in class IV demonstrated significantly elevated neurohumoral mediator levels, except endothelin-1, in comparison with patients in classes I-III. Neurohumoral mediator levels had a significant negative correlation with exercise capacity. Stepwise regression analysis revealed that the BNP to ANP ratio (BNP/ANP) was the most powerful independent factor for total pulmonary resistance (r = 0.85, p = 0.0071) and cardiac index (r = 0.84, p = 0.009). Adrenomedullin was significantly correlated with BNP (r = 0.53, p = 0.03), endothelin-1 (r = 0.66, p = 0.006), and BNP/ANP (r = 0.73, p = 0.0009). ANP and BNP decreased from 196 +/- 213 and 494 +/- 361 pg/ml at baseline to 74 +/- 47 and 153 +/- 133 pg/ml at 1 month, respectively. There was an apparent re-increase in both ANP (187 +/- 194 pg/ml) and BNP (466 +/- 621 pg/ml) at 3 months, regardless of improvement in NYHA class and exercise capacity after long-term PGI2 treatment. In contrast, adrenomedullin decreased from 3.0 +/- 2.2 (baseline) to 1.7 +/- 0.7 fmol/ml at 1 month and 1.6 +/- 0.5 fmol/ml at 3 months. Adrenomedullin was slightly increased at 6-12 months (2.1 +/- 0.9 fmol/ml) without statistical significance. There was a significant relationship between the changes in adrenomedullin at 3 months compared to values at initiation of PGI2 therapy and the changes in mean pulmonary arterial pressure (r = 0.97, p = 0.0041).. Plasma levels of neurohumoral mediators are useful for assessing the severity of primary pulmonary hypertension. In particular, adrenomedullin was valuable for evaluating both cardiac performance and pulmonary hemodynamics after long-term treatment with PGI2 in patients with primary pulmonary hypertension.

Topics: Adolescent; Adrenomedullin; Antihypertensive Agents; Atrial Natriuretic Factor; Child; Child, Preschool; Endothelin-1; Epoprostenol; Exercise Tolerance; Female; Hemodynamics; Humans; Hypertension, Pulmonary; Infusions, Intravenous; Male; Natriuretic Peptide, Brain; Peptides

The agents which increase intracellular cyclic AMP (cAMP) or cyclic GMP (cGMP) have been found to counteract the effects of the vasoconstrictive agents such as endothelin-1 (ET-1). To clarify the mechanism of this interaction, we evaluated the activities of mitogen-activated protein kinase (MAPK) cascade, one of the important signal transduction system of ET-1. Beraprost sodium, an analogue of PGI2, and adrenomedullin, a cAMP-raising agent, inhibited ET-1-induced activation of MAPK. Dibutyryl cAMP (Bt2-cAMP) and 8-bromo-cGMP (8-Br-cGMP), cell permeable analogues of cAMP and cGMP, were also able to inhibit the activation of MAPK and MAPK kinase (MAPKK) by ET-1 without interfering basal activities. In contrast, phorbol 12, 13-dibutylate (PDBu)-induced activation of MAPK and MAPKK was inhibited by Bt2-cAMP but not by 8-Br-cGMP. Interestingly, atrial natriuretic peptide (ANP) partially inhibited PDBu-induced activation of MAPK and MAPKK. These results indicate that cAMP and cGMP inhibit ET-1-induced activation of MAPK in cultured mesangial cells at different steps; the former might inhibit at a step downstream of PKC and the latter prior to PKC. The data also suggest that ANP might have cGMP-independent effect on MAPK.

Topics: Adrenomedullin; Animals; Bucladesine; Calcium-Calmodulin-Dependent Protein Kinases; Cells, Cultured; Cyclic AMP; Cyclic GMP; Endothelin-1; Enzyme Activation; Enzyme Inhibitors; Epoprostenol; Glomerular Mesangium; Mitogen-Activated Protein Kinase Kinases; Nucleotides, Cyclic; Peptides; Phorbol 12,13-Dibutyrate; Protein Kinases; Rats; Signal Transduction