Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0016382 (flushing)
 6,387 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Phosphorus nuclear magnetic resonance (31P NMR) can be used as a non-destructive method for the simultaneous observation of the major phosphate-containing metabolites (ATP, ADP, nucleotide monophosphate, Pi, sugar phosphate) and intracellular pH in isolated rat kidney. The time course of changes in these metabolites and in cellular pH in the ischaemic kidney are examined at two temperatures and in the presence of different flushing media. ATP is rapidly depleted while the pH change is slower and shows biphasic behaviour. Pi production and total nucleotide (ATP and ADP) depletion also occur on the same time-scale as the tissue acidification. The relation of these observations to tissue viability is discussed and the possibility of extending the measurements to human organs is considered.
 ...
PMID:Non-destructive measurement of metabolites and tissue pH in the kidney by 31P nuclear magnetic resonance. 4 1

The isolated perfused rat kidney has been used to study the effects of cold ischaemia during ice storage. Tissue adenine nucleotide levels in freeze-clamped kidneys were closely correlated with their function after circulation had been reestablished in the perfusion circuit. The ATP content was depleted to a greater extent than total adenine nucleotide after 8 hr of cold ischaemia but both were considerably diminished after 24 hr. The model was also used to compare four solutions which are available clinically for preliminary flushing of organs in the ice storage preservation technique. The results indicated that for periods of 8 and 24 hr of cold ischaemia, renal function and adenine nucleotide content were significantly better maintained with a solution based on hyperosmolar citrate than with Collins, Sacks, or Perfudex solutions. This study confirmed recent observations of the clinical efficacy of citrate solution, while demonstrating how the isolated perfused rat kidney could be used for rapid screening of modifications in preservation techniques.
 ...
PMID:Evaluation of hypertonic citrate flushing solution for kidney preservation using the isolated perfused rat kidney. 65 4

While the clinical results of orthotopic liver transplantation have greatly improved, the viability of liver grafts and extension of the safe time for preservation are necessary factors in need of improvement. The liver is one of the organs most sensitive to anoxia. The addition of an oxygen carrying agent to the preservation solution was evaluated. Pyridoxalated hemoglobin-polyoxyethylene conjugate (PHP) is used as an oxygen carrier. Viaspan (UW) served as a control solution. Test solution (PHP+UW) composition was composed of a 1:1 mixture of PHP and UW solutions with hemoglobin 4.0g%, hydroxyethyl starch 2.5g%, osmolality 320 mOsm/kg H2O, and colloidal osmotic pressure 33 mmHg. The oxygen carrying capacity of PHP+UW solution is about 10 times higher than UW solution at 4 degrees C. Male Lewis rats (BW: 250-300 g) were divided into five groups. After flushing the solution via the portal vein, rat livers were harvested. Two preservation methods, simple storage and perfusion (0.1 ml/min/g liver), were studied at 4 degrees C for 24 or 48 hours. OxyHb, MetHb, pO2, pH, Na, K, GOT, and GPT of perfusate, hepatic mitochondrial functions after preservation, and tissue adenine nucleotides by HPLC were measured. Light microscopy on the tissue was also performed. No significant differences were noted in perfusate biochemical parameters. Oxygen consumption during the perfusion was significantly higher in the PHP+UW than in the UW group. Hepatic mitochondrial functions and tissue ATP levels were better preserved in perfusion than in simple storage, and in PHP+UW than in UW at 48 hours. The oxygen carrying agent, PHP, can provide significantly higher levels of oxygen to liver grafts and improve graft viability.
 ...
PMID:Does oxygen supply improve graft viability in liver preservation? 139 76

The development of vasodilator drugs that open the K+ channels in blood vessels has been of great academic and practical interest. The discoveries of the ATP-sensitive K+ channel and the glibenclamide-sensitive K+ channel have promoted these interests. In relation to this channel, the cardioprotective effectiveness of a K+ channel opener (Aprikalim) in doses that did not change haemodynamics or collateral blood flow were demonstrated in infarct dog heart. The effects were antagonized by glibenclamide. Thus, ATP-sensitive K+ channels seem to play an important role in this effect. Clinical evaluations of the K+ channel openers are reviewed. The hypotensive effects of the drugs are well-recognized. At present, however, the clinical usefulness of K+ channel openers has not been accepted widely, because of their side-effects including reflex tachycardia, edema, flushing and headache. An approach to reduce these side-effects is critical if these K+ channel openers are to be used as good hypotensive drugs. The K+ channel opener nicorandil has been evaluated as a highly effective antianginal drug. It seems likely that the clinical benefits of nicorandil result from both its K+ channel opening properties and its ability to stimulate smooth muscle guanylate cyclase. Clinical data on the pure-selective K+ channel opener cromakalim (lemakalim) as an antianginal drug is limited. However, on the basis of the vasodilator profile of this drug, it is expected to be useful for this purpose. The application of K+ channel openers to treat other disorders such as bladder instability is limited because of its hypotensive action.
 ...
PMID:[The recent development and the present status of K+ channel opener]. 139 33

Several metabolic fluxes were analyzed during gradual transitions from aerobic to oxygen-limited conditions in chemostat cultures of Pseudomonas mendocina growing in synthetic medium at a dilution rate of 0.25 h-1. P. mendocina growth was glucose limited at high oxygen partial pressures (70 and 20% pO2) and exhibited an oxidative type of metabolism characterized by respiratory quotient (RQ) values of 1.0. A similar RQ value was obtained at low pO2 (2%), and detectable levels of acetic, formic, and lactic acids were determined in the extracellular medium. RQs of 0.9 +/- 0.12 were found at 70% pO2 for growth rates ranging from 0.025 to 0.5 h-1. At high pO2, the control coefficients of oxygen on catabolic fluxes were 0.19 and 0.22 for O2 uptake and CO2 production, respectively. At low pO2 (2%), the catabolic and anabolic fluxes were highly controlled by oxygen. P. mendocina showed a mixed-type fermentative metabolism when nitrogen was flushed into chemostat cultures. Ethanol and acetic, lactic, and formic acids were excreted and represented 7.5% of the total carbon recovered. Approximately 50% of the carbon was found as uronic acids in the extracellular medium. Physiological studies were performed under microaerophilic conditions (nitrogen flushing) in continuous cultures for a wide range of growth rates (0.03 to 0.5 h-1). A cell population, able to exhibit a near-maximum theoretical yield of ATP (YmaxATP = 25 g/mol) with a number of ATP molecules formed during the transfer of an electron towards oxygen along the respiration chain (P/O ratio) of 3, appears to have adapted to microaerophilic conditions.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Metabolic and energetic control of Pseudomonas mendocina growth during transitions from aerobic to oxygen-limited conditions in chemostat cultures. 144 29

Since posttransplant function is closely related to energy status after the storage period, the aim of our study was to determine high-energy phosphates in rat small bowels after 21 h of simple ischemic cold storage using different storage solutions. We compared Eurocollins-solution, Bretschneiders-HTK-solution and a modified University of Wisconsin-solution. After flushing the small bowel both intravascularly and intraluminally with the protecting solution, segments of rat small bowel were stored in the same solution at 4 degrees C for 21 h. Determination of high-energy phosphates by high-performance liquid chromatography were done at indicated times. We found that small bowel stored in Eurocollins-solution produced the best graft viability after 21 h of cold storage by maintaining a sufficient level of high-energy phosphates. The high ATP levels were produced by the pronounced anaerobic glycolysis which was facilitated by the high concentration of glucose in the Eurocollins-solution.
 ...
PMID:Small bowel tissue high-energy phosphate alterations during hypothermic storage using different protecting solutions. 158 32

The metabolic response of the rat liver to flushing and reflushing with Marshall's solution at pH 7.2 or pH 7.8 has been studied by 31P nuclear magnetic resonance spectroscopy. The changes in intracellular pH, inorganic phosphate, ATP and phosphomonoesters have been determined from the 31P spectra. We show that the intracellular pH at any stage of the flushing protocol is largely independent of the pH of the medium when using these solutions. However, we demonstrate that there are differences between the efficiency of the two solutions in respect of the rates of hydrolysis of ATP and accumulation of phosphomonoesters. There were also differences in the response of the livers upon reflushing--those livers reflushed at pH 7.2 resynthesized ATP from a lower initial concentration to achieve ATP concentrations similar to those restored in livers reflushed at pH 7.8. These trends were mirrored in the responses of the phosphomonoester peaks (which contain a contribution from AMP). We conclude that short-term control of liver metabolism during hypothermia is possible by use of solutions of different pH, but that for longer-term storage, other approaches may be necessary to maintain metabolic integrity.
 ...
PMID:Biochemical consequences of reflushing hypothermically-stored liver with fresh cold perfusate. Studies on rat liver using 31P NMR spectroscopy. 264 Dec 99

Nuclear magnetic resonance (NMR) spectroscopy was used in the study of rat livers following flushing with a clinically used preservation solution containing either 12 or 30% (v/v) Me2SO. The extent of equilibration of Me2SO in the tissue after 10-15 min of perfusion with Me2SO and again after subsequent washout with Me2SO-free medium was assessed by 1H NMR spectroscopy. 31P NMR spectroscopy was used to follow the changes in ATP, ADP, inorganic phosphate, and tissue pH. The data show that 1H NMR spectroscopy can be used as a sensitive and rapid method of assessing the equilibration and concentration of compounds such as Me2SO, since these compounds are likely to be present at concentrations greatly in excess of other constituents of the medium and will therefore give rise to strong, easily detected signals. At the same time, 31P NMR spectroscopy can be used to monitor the metabolic status of the tissue reflected in the levels of ATP, ADP, and inorganic phosphate, as well as being a noninvasive monitor of intracellular pH. The possibility of determining the tissue pH in the presence of solutes such as Me2SO is discussed.
 ...
PMID:Studies on cryoprotectant equilibration in the intact rat liver using nuclear magnetic resonance spectroscopy: a noninvasive method to assess distribution of dimethyl sulfoxide in tissues. 270 27

31P nuclear magnetic resonance spectroscopy has been used to study rat livers following flushing with the University of Wisconsin (UW) lactobionate/raffinose solution (N. Jamieson, R. Sundberg, S. Lindell, J. Southard, and F.O. Belzer, Cryobiology 24, 573-574, 1987; M. Kalayoglu, H. Sollinger, R. Stratta, A. D'Alessandro, R. Hoffman, J. Pirsch, and F. O. Belzer, Lancet 1, 617-619, 1988). These studies have revealed that despite the improved storage properties that have been reported for this solution, hepatic ATP and ADP declined at a rate similar to that seen in the more commonly used Marshall's or Collins' solutions. However, there was a significant inhibition of the developing acidosis, such that by 5 hr postflush, the intracellular pH was 7.17 +/- 0.06 (mean +/- SD, n = 5) compared to 6.90 +/- 0.06 for Marshall's solution (4 hr postflush) and 6.94 +/- 0.04 for Collins' solution (4 hr postflush). This did not appear to be due to a buffering effect of the solution, as this was found to be relatively low, but was probably due to a modification of hepatic metabolism caused by the solution itself.
 ...
PMID:The response of liver to lactobionate/raffinose (University of Wisconsin--UW) solution during hypothermic preservation: a study using 31phosphorus nuclear magnetic resonance. 274 88

Rat kidneys were flushed in situ with selected preservation solutions prior to clamping the renal vessels for 1 hour. Collins and Euro-Collins flushing solutions did not appear to protect the physiologic or morphologic status of rat kidneys when examined 2 days after the ischemic insult. These experimental groups exhibited serum creatinine levels similar to those seen in ischemic controls, correspondingly low urine creatinine levels, anuria, and significant deterioration of the uriniferous tubules as revealed by light and electron microscopy. In situ flushing with hypertonic Sacks or isotonic phosphate-buffered sucrose solutions, however, resulted in significant improvements in serum and urine creatinine levels, prevented anuria, and dramatically improved the morphologic integrity of the uriniferous tubules. Flushing with a phosphate-buffered sucrose solution that contained ATP-MgCl2 further improved the physiologic and morphologic status of ischemic kidneys to the point that they were indistinguishable from the nonischemic controls. The degree of protection obtained by flushing kidneys with the isotonic phosphate-buffered sucrose solution plus ATP-MgCl2 is greater than that provided by any other single pretreatment or posttreatment for ischemia that is currently available. We, therefore, believe that the use of this procedure can provide a valuable approach to surgical situations in which postischemic acute renal failure is a potential problem.
 ...
PMID:Protection of kidneys from acute renal failure resulting from normothermic ischemia. 660 9


1 2 3 Next >>