Search results for "Permeability"
showing 10 items of 596 documents
Controlled reperfusion after hypothermic heart preservation inhibits mitochondrial permeability transition-pore opening and enhances functional recov…
2006
We investigated whether low-pressure reperfusion may attenuate postischemic contractile dysfunction, limits necrosis and apoptosis after a prolonged hypothermic ischemia, and inhibits mitochondrial permeability transition-pore (MPTP) opening. Isolated rats hearts ( n = 72) were exposed to 8 h of cold ischemia and assigned to the following groups: 1) reperfusion with low pressure (LP = 70 cmH2O) and 2) reperfusion with normal pressure (NP = 100 cmH2O). Cardiac function was assessed during reperfusion using the Langendorff model. Mitochondria were isolated, and the Ca2+resistance capacity (CRC) of the MPTP was determined. Malondialdehyde (MDA) production, caspase-3 activity, and cytochrome c …
Pharmacological activity of PF-904 in guinea pig in vivo, and on human bronchus and neutrophils in vitro.
1997
The effects of PF-904 (4-amino-1-ethyl-6-methylpyrazino[2,3-c][1,2,6]thiadiazine 2,2-dioxide), a pyrazinothiadiazine derivative, were examined in guinea-pig airways in vivo, in human isolated bronchus and human polymorphonuclear leukocytes. PF-904 (12.5-200 mg/kg, intraduodenal) reduced bronchoconstriction in response to histamine, arachidonic acid, platelet-activating factor (PAF) and methacholine. PF-904 (50-200 mg/kg) prevented PAF-induced airways hyperreactivity and inhibited antigen-induced bronchoconstriction, airway microvascular leakage and eosinophil lung accumulation, but antigen-induced airways hyperresponsiveness was not reduced. PF-904 (1 microM-1 mM) produced complete inhibiti…
Simultaneous controlled iontophoretic delivery of pramipexole and rasagiline in vitro and in vivo: Transdermal polypharmacy to treat Parkinson's dise…
2018
[EN] Effective treatment of Parkinson's disease (PD) involves administration of therapeutic agents with complementary mechanisms of action in order to replenish, sustain or substitute endogenous dopamine. The objective of this study was to investigate anodal co-iontophoresis of pramipexole (PRAM; dopamine agonist) and rasagiline (RAS; MAO-B inhibitor) in vitro and in vivo. Passive permeation of PRAM and RAS (20 mM each) across porcine skin after 6 h was 15.7 +/- 1.9 and 16.0 +/- 2.9 mu g/cm(2), respectively. Co-iontophoresis at 0.15, 0.3 and 0.5 mA/cm(2) resulted in statistically significant increases in delivery of PRAM and RAS; at 0.5 mA/cm(2), cumulative permeation of PRAM and RAS was 61…
Magnetic resonance pharmacokinetic imaging clusterization of hepatocellular carcinomas as a means to grade tumor aggressiveness.
2012
Hepatocellular carcinoma (HCC) management takes into account clinical and radiological findings, such as tumor stage, hepatic functional status and clinical symptoms. It is necessary to evaluate the number, size and location of the lesions. However, lesion aggressiveness is not considered in this therapeutic workflow, although the biology and the growth rate of the lesions have an important impact on survival. The aim of this work was to establish if the quantitative pharmacokinetic assessment of dynamic contrast-enhanced magnetic resonance images of HCC can separate lesions with different microvascular properties and biological evolution. Forty five patients with HCC and dynamic contrast-e…
Stimulation of regional lymphatic and blood flow by epicutaneous oxazolone.
2002
The application of the epicutaneous antigen oxazolone results in persistent induration and erythema; however, the relative changes in lymph and blood flow in the inflammatory skin are largely unknown. To define the contribution of lymph and blood flow to the clinical appearance of cutaneous inflammation, we studied the sheep ear after the application of oxazolone. As a model for the study of these changes, the sheep ear had several experimental advantages: 1) a simplified superficial vascular network, 2) defined lymphatic drainage, and 3) an avascular and alymphatic cartilaginous barrier. Lymph flow was continuously monitored by cannulation of the prescapular efferent lymph duct. Blood flo…
Increased Expression of AQP 1 and AQP 5 in Rat Lungs Ventilated with Low Tidal Volume is Time Dependent
2014
BACKGROUND AND GOALS: Mechanical ventilation (MV) can induce or worsen pulmonary oedema. Aquaporins (AQPs) facilitate the selective and rapid bi-directional movement of water. Their role in the development and resolution of pulmonary oedema is controversial. Our objectives are to determine if prolonged MV causes lung oedema and changes in the expression of AQP 1 and AQP 5 in rats. METHODS: 25 male Wistar rats were subjected to MV with a tidal volume of 10 ml/kg, during 2 hours (n = 12) and 4 hours (n = 13). Degree of oedema was compared with a group of non-ventilated rats (n = 5). The expression of AQP 1 and AQP 5 were determined by western immunoblotting, measuring the amount of mRNA (prev…
Time sequence and site of fluid accumulation in experimental neurogenic pulmonary edema.
1976
The initial phase of pulmonary edema development following intracranial pressure elevation was studied by means of transmission electron microscopy. Using perfusion fixation and application of a blood tracer (HRP horseradish peroxidase) the time sequence and site of fluid leakage out of pulmonary vessels was demonstrated: - passage of edema fluid through intercellular clefts of alveolar capillary endothelium - edema accumulation in alveolar interstitial tissue - draining of edema fluid from the alveolar septum to the interstitium of terminal bronchioli and to lymphatic vessels. An early interepithelial fluid leakage out of the alveolar wall remains questionable.
Method for functional study of mitochondria in rat hypothalamus
2008
1872-678X (Electronic) Journal Article Research Support, Non-U.S. Gov't; Different roles of mitochondria in brain function according to brain area are now clearly emerging. Unfortunately, no technique is yet described to investigate mitochondria function in specific brain area. In this article, we provide a complete description of a procedure to analyze the mitochondrial function in rat brain biopsies. Our two-step method consists in a saponin permeabilization of fresh brain tissues in combination with high-resolution respirometry to acquire the integrated respiratory rate of the biopsy. In the first part, we carefully checked the mitochondria integrity after permeabilization, defined exper…
The effects of three absorption-modifying critical excipients on the in vivo intestinal absorption of six model compounds in rats and dogs.
2018
Pharmaceutical excipients that may affect gastrointestinal (GI) drug absorption are called critical pharmaceutical excipients, or absorption-modifying excipients (AMEs) if they act by altering the integrity of the intestinal epithelial cell membrane. Some of these excipients increase intestinal permeability, and subsequently the absorption and bioavailability of the drug. This could have implications for both the assessment of bioequivalence and the efficacy of the absorption-enhancing drug delivery system. The absorption-enhancing effects of AMEs with different mechanisms (chitosan, sodium caprate, sodium dodecyl sulfate (SDS)) have previously been evaluated in the rat single-pass intestin…
First Evidence for a Crosstalk Between Mitochondrial and NADPH Oxidase-Derived Reactive Oxygen Species in Nitroglycerin-Triggered Vascular Dysfunction
2008
Chronic nitroglycerin treatment results in development of nitrate tolerance associated with endothelial dysfunction (ED). We sought to clarify how mitochondria- and NADPH oxidase (Nox)-derived reactive oxygen species (ROS) contribute to nitrate tolerance and nitroglycerin-induced ED. Nitrate tolerance was induced by nitroglycerin infusion in male Wistar rats (100 microg/h/4 day) and in C57/Bl6, p47(phox/) and gp91(phox/) mice (50 microg/h/4 day). Protein and mRNA expression of Nox subunits were unaltered by chronic nitroglycerin treatment. Oxidative stress was determined in vascular rings and mitochondrial fractions of nitroglycerin-treated animals by L-012 enhanced chemiluminescence, revea…