Abstract:
:Hypericin is a photosensitizing plant pigment from Hypericum perforatum with multiple modes of light-induced biological activities due to production of singlet oxygen and/or excited-state proton transfer with consequent pH drop in the hypericin environment. In the present work, we studied the effects of three inhibitors of crucial mechanisms responsible for intracellular pH (pHi) regulation on hypericin phototoxicity: N-ethylmaleimide (NEM), an inhibitor of H+-ATPase, 5'-(N,N-dimethyl)-amiloride (DMA), an inhibitor of Na+/H+ exchanger, and omeprazole (OME), an inhibitor of H+K+-ATPase. Our experiments show that the effect of hypericin at 1 x 10(-5) and 1 x 10(-6) mol x l(-1) was significantly potentiated by NEM (1 x 10(-7)-1 x 10(--9) mol x l(-1)) and DMA (1 x 10(-6) and 1 x 10(-7) mol x l(-1)) in leukemic CEM cell line. On the other hand, OME had no significant effect on hypericin cytotoxicity. Our results support the hypothesis that the excited-state proton transfer and the consequent acidification of hypericin environment could play a role in the biological activity of hypericin.
journal_name
Physiol Resjournal_title
Physiological researchauthors
Mirossay A,Mirossay L,Sarisský M,Papp P,Mojzis Jsubject
Has Abstractpub_date
2002-01-01 00:00:00pages
641-4issue
6eissn
0862-8408issn
1802-9973journal_volume
51pub_type
杂志文章abstract::Sodium borocaptate (BSH, Na2Bl2HllSH), a slow neutron-capture compound, was injected into the left forebrain ventricle of 1-week-old rats (150 microg BSH/3 microl phosphate buffered saline). After 90 min, the animals were irradiated by epithermal neutrons (LVR-15 nuclear reactor in Rez near Prague, flux density 8.8 x ...
journal_title:Physiological research
pub_type: 杂志文章
doi:
更新日期:1997-01-01 00:00:00
abstract::The mood and behavior of individuals result from an orchestra of many factors. Among them steroids play an important role; however, only several common hormones have been investigated in this respect. It has been demonstrated that some steroid metabolites long considered merely the products of steroid hormone metaboli...
journal_title:Physiological research
pub_type: 杂志文章
doi:10.33549/physiolres.933067
更新日期:2015-01-01 00:00:00
abstract::Whole blood surface tension of 15 healthy subjects recorded by the ring method was investigated in the temperature range from 20 to 40 degrees C. The surface tension omega as a function of temperature t ( degrees C) is described by an equation of linear regression as omega(t) = (-0.473 t + 70.105) x 10(-3) N/m. Blood ...
journal_title:Physiological research
pub_type: 杂志文章
doi:
更新日期:2007-01-01 00:00:00
abstract::Differential pulse voltammetry with a carbon fibre microelectrode (ME) was used in pentobarbital-anaesthetized rats for monitoring the stobadine current (STB.C) on both sides of the blood-brain barrier (BBB) in the arterial bloodstream (BS) and in the corpus striatum (CS). The STB.C exhibited a distinct peak at a pola...
journal_title:Physiological research
pub_type: 杂志文章
doi:
更新日期:1996-01-01 00:00:00
abstract::The aim of this study was to explore changes in plasma vascular endothelial growth factor (VEGF) in aged patients who undergone transcatheter aortic valve implantation or balloon angioplasty for the treatment of aortic stenosis. Plasma VEGF was measured in subjects with diabetes mellitus type 2 (DM) (n=21, age 79.2+/-...
journal_title:Physiological research
pub_type: 杂志文章
doi:10.33549/physiolres.932857
更新日期:2014-01-01 00:00:00
abstract::A patent ductus arteriosus (DA) was maintained in newborn rats (Wistar strain) by administering prostaglandin E2 (PG E2) in doses of 15 micrograms.kg-1 at 30 min intervals up to 300 min after birth. In the control animals, the DA was functionally closed 300 min after birth. The lumen was blocked by clustered endotheli...
journal_title:Physiological research
pub_type: 杂志文章
doi:
更新日期:1992-01-01 00:00:00
abstract::The effect of suramin, an inhibitor of G protein regulated signalling, was studied on the membrane currents induced by noxious heat and by capsaicin in cultured dorsal root ganglia neurones isolated from neonatal rats. Whole-cell responses induced by a heat ramp (24-52 degrees C) were little affected by suramin. The n...
journal_title:Physiological research
pub_type: 杂志文章
doi:
更新日期:2002-01-01 00:00:00
abstract::Adiponectin is an adipokine increasing glucose and fatty acid metabolism and improving insulin sensitivity. The aim of this study was to investigate the role of adiponectin in the regulation of adipocyte lipolysis. Human adipocytes isolated from biopsies obtained during surgical operations from 16 non-obese and 17 obe...
journal_title:Physiological research
pub_type: 杂志文章
doi:10.33549/physiolres.931863
更新日期:2011-01-01 00:00:00
abstract::Metabolic acidosis could occur due to either endogenous acids accumulation or bicarbonate loss from the gastrointestinal tract or commonly from the kidney. This study aimed to investigate the possible underlying mechanism(s) of chronic acidosis-induced cardiac contractile and electrical changes in rats. Twenty four ad...
journal_title:Physiological research
pub_type: 杂志文章
doi:10.33549/physiolres.933171
更新日期:2016-12-13 00:00:00
abstract::The expression of aquaporins (AQPs) in the fetal porcine urinary tract and its relation to gestational age has not been established. Tissue samples from the renal pelvis, ureter, bladder and urethra were obtained from porcine fetuses. Samples were examined by RT-PCR (AQPs 1-11), QPCR (AQPs positive on RT-PCR), and imm...
journal_title:Physiological research
pub_type: 杂志文章
doi:10.33549/physiolres.933545
更新日期:2018-05-04 00:00:00
abstract::Fever developing after intracerebral injections of lipopolysaccharide (LPS) to guinea-pigs were monophasic, with only one peak of inner body temperature slowly developing and longlasting in a dose range 20 to 200 ng of LPS. Latency time was inversely related to the dose of LPS. Indomethacin injected to the third brain...
journal_title:Physiological research
pub_type: 杂志文章
doi:
更新日期:1992-01-01 00:00:00
abstract::Research and clinical implications on novel cardiac biomarkers has intensified significantly in the past few years. The high-sensitive troponin T (hscTnT) assay plays a dominant role in diagnostic algorithm regarding myocardial injury in adults. Despite generally accepted use of hscTnT there are no data about physiolo...
journal_title:Physiological research
pub_type: 杂志文章
doi:10.33549/physiolres.933704
更新日期:2018-05-04 00:00:00
abstract::Pattern of right ventricular pressure (RVP) fall and its afterload dependence were examined by analyzing ventricular pressure curves and corresponding pressure dP/dt phase planes obtained in both ventricles in the rat heart in situ. Time and value of dP/dt(min), and the time constant tau were measured at baseline and ...
journal_title:Physiological research
pub_type: 杂志文章
doi:
更新日期:2004-01-01 00:00:00
abstract::Gastrointestinal hormones play an important role in the neuroendocrine regulation of food intake and postprandial satiety. Ghrelin is a 28-amino acid orexigenic peptide produced mainly by the stomach that is involved in both the long-term regulation of body weight and the short-term regulation of postprandial satiety....
journal_title:Physiological research
pub_type: 杂志文章,评审
doi:
更新日期:2009-01-01 00:00:00
abstract::Three-dimensional electrogram was used for analysis of ischemia manifestation in isolated hearts. Three parameters based on spherical coordination system were used in this study - amplitude of electrical heart vector, its azimuth and elevation. The parameters were presented as a trend. This approach reflected ischemic...
journal_title:Physiological research
pub_type: 杂志文章,评审
doi:
更新日期:2010-01-01 00:00:00
abstract::Cardiac resynchronization therapy (CRT) has proven efficacious in reducing or even eliminating cardiac dyssynchrony and thus improving heart failure symptoms. However, quantification of mechanical dyssynchrony is still difficult and identification of CRT candidates is currently based just on the morphology and width o...
journal_title:Physiological research
pub_type: 杂志文章
doi:10.33549/physiolres.933805
更新日期:2017-12-30 00:00:00
abstract::Data concerning the effect of NO on the function and structure of the heart are controversial. We have studied two main questions: (i) Does the heart muscle reflect the hypertension induced by long-term inhibition of NO synthase? (ii) Since the arginine-NO pathway is also operative in the autonomic nervous system, the...
journal_title:Physiological research
pub_type: 杂志文章
doi:
更新日期:1996-01-01 00:00:00
abstract::Because greater Akt substrate of 160 kDa (AS160) phosphorylation has been reported in insulin-stimulated skeletal muscles without improved Akt activation several hours post-exercise, we hypothesized that prior exercise would result in attenuated AS160 dephosphorylation in insulin-stimulated rat skeletal muscle. Epitro...
journal_title:Physiological research
pub_type: 杂志文章
doi:10.33549/physiolres.933591
更新日期:2018-03-16 00:00:00
abstract::The purpose of this study was to investigate plasma concentrations of cyclic guanosine monophosphate (cGMP) and atrial natriuretic peptide (ANP) during and after real and simulated space flight. Venous blood was obtained 3 min after the beginning and 2 min after the lower body negative pressure maneuver in two cosmona...
journal_title:Physiological research
pub_type: 杂志文章
doi:
更新日期:2001-01-01 00:00:00
abstract::The frequencies of the alleles of XbaI polymorphism in the apolipoprotein B gene were determined in two groups of children, 82 with high (HCG) and 86 with low (LCG) cholesterol levels. A slightly higher incidence of the X2X2 genotype in HCG was found, but the differences were not statistically significant. No relation...
journal_title:Physiological research
pub_type: 杂志文章
doi:
更新日期:1998-01-01 00:00:00
abstract::I am pleased to introduce this special issue of Physiological Research published on the occasion of the 60th anniversary of the Institute of Physiology. It is only a second issue of this kind, the previous one being Physiological Research 53 (Suppl. 1) 2004. Since then, the Institute contributed its expertise to moder...
journal_title:Physiological research
pub_type: 杂志文章
doi:
更新日期:2014-01-01 00:00:00
abstract::Instead of a comprehensive review, we describe the basic undisputed facts and a modest contribution of our group to the fascinating area of the research on mitochondrial uncoupling proteins. After defining the terms uncoupling, leak, protein-mediated uncoupling, we discuss the assumption that due to their low abundanc...
journal_title:Physiological research
pub_type: 杂志文章,评审
doi:
更新日期:2004-01-01 00:00:00
abstract::Ubiquitination is a versatile tool used by all eukaryotic organisms for controlling the stability, function, and intracellular localization of a multitude of proteins. I will attempt to bring together our recent data on the down-regulation of two yeast model proteins, the galactose transporter Gal2 and fructose-1,6-bi...
journal_title:Physiological research
pub_type: 杂志文章,评审
doi:
更新日期:2004-01-01 00:00:00
abstract::The purpose of this study was to determine if there is flow-mediated vasodilation of the femoral artery in response to progressive increases in flow within a physiological range observed in the in vivo experiments. Femoral artery blood flow was determined in conscious rabbits (n = 5) using chronically implanted flowpr...
journal_title:Physiological research
pub_type: 杂志文章
doi:10.33549/physiolres.931672
更新日期:2010-01-01 00:00:00
abstract::Graves' disease affects approximately 3 % of women and 0.5 % of men. The first-choice therapy is based on the administration of thyrostatic drugs. However, approximately half of patients relapse within two years of discontinuation. These patients must then decide whether to re-initiate thyrostatics, which may have ser...
journal_title:Physiological research
pub_type: 杂志文章,评审
doi:10.33549/physiolres.934018
更新日期:2018-11-28 00:00:00
abstract::The complex demodulation (CD) approach was applied to human EEG recorded during a cognitive task performance, including voluntary goal-directed movements. The standard CD algorithm was extended by a simple procedure using frequency histograms and power spectra to select the characteristic frequencies of EEG segments a...
journal_title:Physiological research
pub_type: 杂志文章
doi:
更新日期:1999-01-01 00:00:00
abstract::Familial hypocalciuric hypercalcemia (FHH) type 1, caused by a heterozygous inactivating mutation of the gene encoding the calcium-sensing receptor (CaSR), is characterized by mild to moderate hypercalcemia, hypocalciuria and inappropriately normal or elevated parathyroid hormone (PTH). FHH must be differentiated from...
journal_title:Physiological research
pub_type: 杂志文章
doi:10.33549/physiolres.934522
更新日期:2020-09-30 00:00:00
abstract::Male Wistar rats adapted to artificial light:dark (LD) regimen 12:12 h were whole-body irradiated with a single dose of 9.6 Gy of gamma rays and sham/irradiated in the night in darkness. The rats were examined 60 min, 1, 3 and 5 days after exposure between 22:00 and 01:30 h in the darkness. The results obtained indica...
journal_title:Physiological research
pub_type: 杂志文章
doi:
更新日期:1999-01-01 00:00:00
abstract::Rat skeletal muscle myofibrils were incubated in the presence of D-glucose, D-fructose, D-galactose, D-ribose, D-tagatose, D-arabinose, D-xylose, D-mannose, L-sorbose, L-rhamnose or DL-glyceraldehyde and myofibrillar ATPase activity as well as the extent of glycation was measured. The attachment of sugars to proteins ...
journal_title:Physiological research
pub_type: 杂志文章
doi:
更新日期:1994-01-01 00:00:00
abstract::Hypoxic pulmonary vasoconstriction (HPV) occurs in smooth muscle cells (SMC) from small pulmonary arteries (SPA) and is accompanied by increases in free cytoplasmic calcium ([Ca2+]i) and cytoplasmic pH (pHi). SMC from large pulmonary arteries (LPA) relax during hypoxia, and [Ca2+]i and pHi decrease. Increases in pHi a...
journal_title:Physiological research
pub_type: 杂志文章,评审
doi:
更新日期:2000-01-01 00:00:00