Endothelial dysfunction: A strategic target in the treatment of hypertension?

Endothelial dysfunction is a common feature of hypertension, and it results from the imbalanced release of endothelium-derived relaxing factors (EDRFs; in particular, nitric oxide) and endothelium-derived contracting factors (EDCFs; angiotensin II, endothelins, uridine adenosine tetraphosphate, and cyclooxygenase-derived EDCFs). Thus, drugs that increase EDRFs (using direct nitric oxide releasing compounds, tetrahydrobiopterin, or l-arginine supplementation) or decrease EDCF release or actions (using cyclooxygenase inhibitor or thromboxane A2/prostanoid receptor antagonists) would prevent the dysfunction. Many conventional antihypertensive drugs, including angiotensin-converting enzyme inhibitors, calcium channel blockers, and third-generation β-blockers, possess the ability to reverse endothelial dysfunction. Their use is attractive, as they can address arterial blood pressure and vascular tone simultaneously. The severity of endothelial dysfunction correlates with the development of coronary artery disease and predicts future cardiovascular events. Thus, endothelial dysfunction needs to be considered as a strategic target in the treatment of hypertension. © 2010 Springer-Verlag.postprin

Repressor activator protein 1 induces pro-inflammatory cytokines production in macrophages through NFKB signaling

Abstracts for Oral Presentation: no. OP-5This journal issue including abstracts of 18th Annual Scientific Meeting Institute of Cardiovascular Science and MedicineOBJECTIVES: Repressor activator protein 1 (Rap1), an established telomere-associated protein migrates to the cytoplasm and activates nuclear factor kappa B (NFκB) in human carcinoma cell lines. The present study tested the hypothesis that Rap1 induces production of pro-inflammatory cytokines via NFκB signaling in macrophages, a cell type involved in the development and ...postprin

Deletion of repressor activator protein 1 modulates vascular function in mouse aorta

First joint meeting between the Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists (ASCEPT) and the British Pharmacological Society (BPS) , in association with the Hong Kong Pharmacology Society (HKPS) and the Asia Pacific Federation of Pharmacologists (APFP)Conference Theme: Tomorrow's medicines: pharmacology, patients and populationsOral presentations 9: Cardiovascular and Respiratory 4published_or_final_versio

Three new species of Pyricularia are isolated as Zingiberaceous endophytes from Thailand

A new taxon with Dyrithium-like characteristics was collected from Lake Fuxian in China. The taxon is typical of the Amphisphaeriaceae in that it has relatively large, ostiolate, immersed ascomata, unitunicate asci with a J+ subapical ring, and brown ascospores. It is similar to Dyrithium in that it has muriform ascospores, but considerable confusion surrounds this genus. In Dyrithium asci are bitunicate and lack a J+ subapical ring, while this was not true of our species. A new genus, Dyrithiopsis, therefore is established to accommodate this new taxon. Details of its anamorph also are provided, based on cultural studies. Parsimony analyses of part of the large-subunit rDNA provide further evidence to support the familial placement of this new genus in the Amphisphaeriaceae. The taxonomic position of Dyrithium also is discussed.published_or_final_versio

Acanthostigma and Tubeufia species, including T. claspisphaeria sp. nov., from submerged wood in Hong Kong

Acanthostigma scopulum, Tubeufia claspisphaeria sp. nov. and T. paludosa were identified from submerged wood collected in a small forest stream on Lantau Island, Hong Kong. The collections of Acanthostigma scopulum and Tubeufia paludosa differed slightly from the original descriptions. Tubeufia claspisphaeria differs from previously described species in that it has hook-shaped setae that form radially around the ostiole. This new species is described and illustrated and compared with the most similar species. A dichotomous key to the 16 accepted species in Tubeufia is provided.published_or_final_versio

Prostaglandin E Receptor Subtype 4 Signaling in the Heart: Role in Ischemia/Reperfusion Injury and Cardiac Hypertrophy

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Thyroid hormone affects both endothelial and vascular smooth muscle cells in rat arteries

Hypothyroidism impairs endothelium-dependent dilatations, while hyperthyroidism augments the production of endothelial nitric oxide. Thus, experiments were designed to determine if thyroid hormone causes endothelium-dependent responses, or alleviates diabetic endothelial dysfunction. Isometric tension was measured in rings with or without endothelium of arteries from normal and diabetic Sprague-Dawley rats. Release of 6-keto prostaglandin F1α and thromboxane B2 were measured by enzyme linked immunosorbent assay and protein levels [endothelial nitric oxide synthase (eNOS), cyclooxygenases (COX)] by immunoblotting. Triiodothyronine (T3) caused concentration-dependent (3×10−6–3×10−5 M) relaxations in mesenteric (pEC50, 4.96±0.19) and femoral (pEC50, 4.57±0.35) arteries without endothelium. In femoral arteries of rats with diabetes, 5-methylamino-2-[[(2S,3R,5R,8S,9S)-3,5,9-trimethyl-2-(1-oxo-(1H-pyrrol-2- -yl)propan-2-yl)-1,7-dioxaspiro-(5,5)undecan-8-yl]methyl]benzooxazole-4-carboxylic acid (A23187, 3×10−7 to 10−6 M) caused partly endothelium-dependent contractions. After chronic T3-treatment with (10 μg/kg/day; four weeks), the contractions to A23187 of preparations with and without endothelium were comparable, the thromboxane B2-release was reduced (by 38.1±9.2%). The pEC50 of 9, 11-dideoxy-11α, 9α-epoxymethanoprostaglandin F2α (U46619, TP-receptor agonist) was increased in T3-treated diabetic rats compared with controls (8.53±0.06 vs 7.94±0.09). The protein expression of eNOS increased (by 228%) but that of COX-1 decreased (by 35%) after chronic T3 treatment. In human umbilical vein endothelial cells incubated for one week with T3 (10−10–10−7 M) in the presence but not in the absence of interleukin-1β (1 ng/ml), the expression of eNOS was increased compared to control. In conclusion, thyroid hormone acutely relaxes mesenteric and femoral vascular smooth muscle, but given chronically reduces the release of endothelium-derived vasoconstrictor prostanoids while enhancing the responsiveness of TP receptors of vascular smooth muscle.postprin

The family Pleosporaceae: intergeneric relationships and phylogenetic perspectives based on sequence analyses of partial 28S rDNA

The Pleosporaceae is an important loculoascomycete family. There has been disagreement, however, regarding the taxonomic placement of many genera within this family. This study investigates phylogenetic relationships among the genera Cochliobolus, Kirschsteiniothelia, Leptosphaerulina, Macroventuria, Pleospora, Pyrenophora, and Wettsteinina. Partial 28S rDNA sequences from taxa within these genera were analyzed with maximum parsimony, likelihood and Bayesian methods. Cochliobolus can be segregated broadly into two groups as previously proposed. Pleospora is polyphyletic in its current sense. Taxa with Stemphylium anamorphs are closely related to Cochliobolus and fit within the Pleosporaceae, whereas the affinities of Pleospora herbarum and P. ambigua are still ambiguous. Pyrenophora constitutes a monophyletic group within the Pleosporaceae, whereas Leptosphaerulina and Macroventuria appear to share phylogenetic affinities with the Leptosphaeriaceae and Phaeosphaeriaceae. Phylogenies indicate that Wettsteinina should be excluded from the Pleosporaceae. Similar findings are reported for Kirschsteiniothelia, which is probably polyphyletic. Anamorphic characters appear to be significant (especially in Cochliobolus) while ascospore morphologies, such as shape and color and substrate occurrence are poor indicators of phylogenetic relationships among these loculoascomycetes.published_or_final_versio

Molecular and morphological characterization of Pyricularia and allied genera

The phylogenetic relationships of Pyricularia species and species from related genera were established from sequences of the internal transcribed spacer ribosomal RNA gene. Phylogenetic analysis disclosed a consistent correlation with spore morphology. Most Pyricularia species studied, and two species of Dactylaria that have obpyriform conidia, fell within the Magnaporthaceae cluster with high bootstrap support. Pyricularia variabilis was more related to Dactylaria, Tumularia or Ochroconis species than to the Magnaporthaceae. Dactylaria and species of Nakataea, Ochroconis, Pyriculariopsis and Tumularia were distinct from the Magnaporthaceae, and the genus Dactylaria is polyphyletic. The combination of morphological and molecular characters, such as spore morphology and ITS ribosomal DNA sequences data, suggested that conidial shape could be a primary character to distinguish Pyricularia from related genera.published_or_final_versio

Microfungi on the Pandanaceae: Linocarpon lamiae sp. nov., L. siamensis sp. nov. and L. suthepensis sp. nov. are described with a key to Linocarpon species from the Pandanaceae

Linocarpon species are reported from Pandanaceae in Australia, Brunei, Hong Kong, Nepal, New Zealand, Philippines, Seychelles, Thailand and Vanuatu. Linocarpon lammiae sp. nov. were collected on decaying leaves of Pandanus tectorius in Hong Kong. Linocarpon siamensis sp. nov. and L. suthepensis sp. nov. were collected from decaying leaves of P. penetrans in Thailand. These taxa are described, illustrated and compared with Linocarpon species with similar ascospore morphology and dimensions. Included are a synoptic table, which compares the new species to similar known species, and a dichotomous key to species of Linocarpon known from members of the Pandanaceae.published_or_final_versio