ABSTRACT
The cardiac ATP-sensitive potassium (K(ATP)) channel is potentially composed of an inward rectifier potassium channel (Kir6.1 and/or Kir6.2) subunit and the cardiac type of sulfonylurea receptor (SUR2A). We reported that cardiac Kir6.1 mRNA and protein are specifically upregulated in the non-ischemic as well as the ischemic regions in rats with myocardial ischemia, suggesting that humoral and/or hemodynamic factors are responsible for this regulation. In the present study, pretreatment with TCV-116, an angiotensin (Ang) II type 1 receptor antagonist, completely inhibited the upregulation of Kir6.1 mRNA and protein expression in both regions of rat hearts subjected to 60 min of coronary artery occlusion followed by 24 h of reperfusion; whereas pretreatment with lisinopril, an Ang converting enzyme (ACE) inhibitor, partly inhibited this upregulation. Except for rats pretreated with TCV-116, Kir6.1 mRNA levels were positively correlated with those for brain natriuretic peptide (BNP), a molecular indicator of regional wall stress, in both the non-ischemic and the ischemic regions. Plasma Ang II levels were not elevated in rats with control myocardial ischemia compared with sham rats. Thus, the stress-related induction of cardiac Kir6.1 mRNA and protein expression under myocardial ischemia is inhibited by pretreatment with an AT1 antagonist, but also in part by an ACE inhibitor, suggesting that activation of local renin-angiotensin system may play a role.
Subject(s)
Angiotensin II/metabolism , Myocardial Ischemia/metabolism , Potassium Channels, Inwardly Rectifying , Potassium Channels/metabolism , Renin-Angiotensin System/physiology , Tetrazoles , Angiotensin I/blood , Angiotensin II/antagonists & inhibitors , Angiotensin II/blood , Animals , Benzimidazoles/pharmacology , Biphenyl Compounds/pharmacology , Blotting, Northern , Blotting, Western , DNA, Complementary/metabolism , Lisinopril/pharmacology , Male , Myocardium/metabolism , Natriuretic Peptide, Brain/pharmacology , RNA/metabolism , RNA, Messenger/metabolism , Random Allocation , Rats , Rats, Wistar , Time Factors , Up-Regulation/drug effectsABSTRACT
Sporulation of four species of filamentous fungi, namely Aspergillus fumigatus, Fusarium solani, Penicillium expansum and Rhizopus oryzae, was suppressed by gaseous contact with citron, lavender and thyme oils and, to a lesser extent, by that of perilla and tea tree oils. Lemongrass and cinnamon bark oils were scarcely active. The antisporulating effect of the essential oils was not observed when they were applied as a solution, indicating that their vapours were the active form. Moreover, exposure of fungal cultures to vapours of the active essential oils caused curling of the tips of aerial hyphae (R. oryzae) or incomplete development of conidiophores (A. fumigatus). These antisporulating effects of the vapourizing essential oils seemed to be correlated with their respiration-inhibitory activity, rather than with their growth-inhibitory activity.
Subject(s)
Fungi/drug effects , Fungi/growth & development , Oils, Volatile/pharmacology , Oxygen Consumption/drug effects , Spores, Fungal/drug effects , Fungi/ultrastructure , Gases , Microscopy, Electron, Scanning , Oils, Volatile/chemistry , Plant Oils/chemistry , Plant Oils/pharmacology , Spores, Fungal/ultrastructureABSTRACT
Hydroxyapatite (HAp) microcrystals were synthesized by a neutralization reaction of Ca(OH)2 suspension and H3PO4 solution using an ultrasonic homogenizer. The in vitro interaction of HAp microcrystals with rat peritoneal macrophages was investigated by measuring the viability, acid phosphatase (ACP) activity, lactate dehydrogenase (LDH) activity and intracellular calcium content. HAp calcined at 800 degrees C and alpha-alumina particles (alumina) were used as comparative materials. Macrophages actively phagocytosed HAp microcrystals by dissolving them. However, no damage in macrophages exposed to HAp microcrystals was observed by transmission electron microscopy. Macrophages in the presence of HAp microcrystals showed less ACP and LDH activity and higher intracellular calcium content than those in the presence of calcined HAp and alumina. HAp microcrystals had excellent biocompatibility to macrophages as well as sintered HAp.
Subject(s)
Biocompatible Materials/pharmacology , Durapatite/pharmacology , Macrophages, Peritoneal/drug effects , Acid Phosphatase/metabolism , Aluminum Oxide/pharmacology , Animals , Biocompatible Materials/chemical synthesis , Biocompatible Materials/chemistry , Calcium/analysis , Calcium Hydroxide/chemistry , Cell Survival/drug effects , Crystallization , Durapatite/chemical synthesis , Durapatite/chemistry , Hot Temperature , Intracellular Fluid/chemistry , L-Lactate Dehydrogenase/metabolism , Macrophages, Peritoneal/enzymology , Macrophages, Peritoneal/physiology , Male , Microscopy, Electron , Phagocytosis , Phosphoric Acids/chemistry , Rats , Rats, Sprague-Dawley , SolubilityABSTRACT
The treatment of ICR mice with i.p. injections (0.14 g/kg/day) of the extract of Capsella bursa-pastoris herb (Cruciferae) caused 50 to 80% inhibition of the solid growth of Ehrlich tumor cells that had been inoculated into the s.c. tissue of the animals. The tumor lumps in the treated mice showed multifocal necroses and the infiltartion of host fibrous tissue cells. Experiments were also performed to isolate and identify the active component for the antitumor action, and an acidic substance was isolated in crystalline form from the herb extract. This acidic substance was identified as fumaric acid and was effective in inhibiting the growth of Ehrlich solid tumor at a dose of 10 mg/kg/day. The 50% lethal dose (i.p.) of this acid was 266 mg/kg.