Ca2+-Containing Modified Krebs Solution

2014 ◽  
Vol 2014 (3) ◽  
pp. pdb.rec076844-pdb.rec076844
Keyword(s):  
Krebs Solution

Physicochemical study of basement membrane properties iii. diffusion of proline, glucose and insulin in krebs solution

1988 ◽  
Vol 85 ◽  
pp. 391-397
Author(s):  
Bo Tao Fan ◽  
Françoise Simonnet ◽  
Jean Schaeverbeke ◽  
Gérard Lapluye
Keyword(s):  
Basement Membrane ◽  
Membrane Properties ◽  
Physicochemical Study ◽  
Krebs Solution

Stability of Prostacyclin in Human Plasma and Whole Blood: Studies on the Protective Effect of Albumin

1981 ◽  
Vol 46 (03) ◽  
pp. 645-647 ◽  
Author(s):  
M A Orchard ◽  
C Robinson
Keyword(s):  
Platelet Aggregation ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Protective Effect ◽  
Whole Blood ◽  
Bovine Serum ◽  
Fatty Acid Content ◽  
Krebs Solution ◽  
Antiaggregatory Activity ◽  
Free Plasma

SummaryThe biological half-life of prostacyclin in Krebs solution, human cell-free plasma or whole blood was measured by bracket assay on ADP-induced platelet aggregation. At 37°C, pH 7.4, plasma and blood reduced the rate of loss of antiaggregatory activity compared with Krebs solution. The protective effect of plasma was greater than that of whole blood. This effect could be partially mimicked by the addition of human or bovine serum albumin to the Krebs solution. The stabilisation afforded by human serum albumin was dependent on the fatty acid content of the albumin, although this was less important for bovine serum albumin.

Effect of low chloride on relaxation in hamster diaphragm muscle

1986 ◽  
Vol 61 (1) ◽  
pp. 180-184 ◽  
Author(s):  
S. A. Esau ◽  
N. Sperelakis
Keyword(s):  
Membrane Potential ◽  
Muscle Fatigue ◽  
Time Constant ◽  
Diaphragm Muscle ◽  
Resting Membrane Potential ◽  
Krebs Solution ◽  
Sarcolemmal Membrane ◽  
Cl Conductance

With muscle fatigue the chloride (Cl-) conductance of the sarcolemmal membrane decreases. The role of lowered Cl- conductance in the prolongation of relaxation seen with fatigue was studied in isolated hamster diaphragm strips. The muscles were studied in either a Krebs solution or a low Cl- solution in which half of the NaCl was replaced by Na-gluconate. Short tetanic contractions were produced by a 160-ms train of 0.2-ms pulses at 60 Hz from which tension (T) and the time constant of relaxation were measured. Resting membrane potential (Em) was measured using KCl-filled microelectrodes with resistances of 15–20 M omega. Mild fatigue (20% fall in tension) was induced by 24–25 tetanic contractions at the rate of 2/s. There was no difference in Em or T in the two solutions, either initially or with fatigue. The time constant of relaxation was greater in low Cl- solution, both initially (22 +/- 3 vs. 18 +/- 5 ms, mean +/- SD, P less than 0.05) and with fatigue (51 +/- 18 vs. 26 +/- 7 ms, P less than 0.005). Lowering of sarcolemmal membrane Cl- conductance appears to play a role in the slowing of relaxation of hamster diaphragm muscle seen with fatigue.

Abstract 241: Endothelial Function is Preserved with Endoscopic Vein Harvest for Lower Extremity Bypass

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Adam R Wheeler ◽  
Daniel E Kendrick ◽  
Matthew T Allemang ◽  
Andre F Gosling ◽  
Anil Nagavalli ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Lower Extremity ◽  
Endothelial Function ◽  
Endothelial Damage ◽  
Krebs Solution ◽  
Force Transducers ◽  
Submaximal Contraction ◽  
Harvesting Techniques ◽  
Harvest Techniques ◽  
Bypass Technique

Objective: Endoscopic vein harvest for lower extremity arterial bypass technique has been questioned due to concern for endothelial damage during procurement. We sought to compare NO mediated endothelial dependent relaxation (EDR) in vein segments harvested with open surgical (OH) versus endoscopic (EH) techniques. Methods: Saphenous vein segments were harvested for lower extremity bypass. 3-4mm vein rings were mounted on force transducers. Segments were mounted in 37° oxygenated Krebs solution and maximally contracted using KCl. NE was used to achieve submaximal contraction. EDR was determined using increasing concentrations of bradykinin (BDK). Endothelial independent relaxation was confirmed using sodium nitroprusside. Two-way ANOVA was used to analyze differences between harvest techniques across BDK concentration. Student t-test was used to examine nitrite levels in each cohort. Results: Vein segments harvested from patients (n=13) led to 28 rings (11 rings; 5 patients EH v. 17;8 OH). Both cohorts achieved moderate relaxation to maximal BDK concentration, [10 -6 M]; (49.5% EH vs. 40.55%, OH, P = .270). Analysis by two way ANOVA for mean % relaxation for BDK concentration [10 -11 - 10 -6 M] showed improved EDR in EH samples compared to OH (P =.029). Mean nitrite tissue bath concentration measurements post-BDK were 279 nM (EH) v. 194 nM (OH) (P = .264). Histology and IHC confirmed intact endothelium by morphometric analysis and CD31 staining. Conclusion: Endothelial function is preserved when utilizing endoscopic harvesting techniques. The advantages of minimally invasive vein procurement for lower extremity bypass can be obtained without concern for damaging venous endothelium.

Effect of Urea, Glycerol, and Mannitol on Basilar and Labyrinthine Arteries

1988 ◽  
Vol 98 (3) ◽  
pp. 226-230 ◽  
Author(s):  
Kazuo Takeda ◽  
Louis D. Lowry ◽  
James J. C. Liu
Keyword(s):  
Hearing Loss ◽  
Smooth Muscles ◽  
Meniere’S Disease ◽  
Meniere's Disease ◽  
Ménière’S Disease ◽  
Bathing Solution ◽  
Krebs Solution ◽  
Menière's Disease ◽  
Ménière's Disease

We studied the effect of urea, glycerol, and mannitol on basilar and labyrinthine arteries of dogs In vitro by use of tension recording methods. When the tissue was exposed to urea or glycerol, temporary relaxation of smooth muscles was initially observed, but was followed by gradually increasing contraction. With mannitol, relaxation of the smooth muscles remained stable as long as mannitol existed in the bathing solution. When the specimens were washed with normal Krebs solution after exposure to any of these three substances, large phasic contractions of the smooth muscles were observed. While only theoretical, we propose a possible explanation for the different effects of these three drugs in the improvement of hearing loss that results from Meniere's disease.

Specificity of a placental factor inhibiting breathing in fetal sheep

1996 ◽  
Vol 8 (3) ◽  
pp. 423 ◽  
Author(s):  
RE Alvaro ◽  
V Rehan ◽  
Almeida V de ◽  
Z Haider ◽  
M Robertson ◽  
...  
Keyword(s):  
High Voltage ◽  
Low Voltage ◽  
Fetal Liver ◽  
Fetal Life ◽  
Krebs Solution ◽  
Fetal Sheep ◽  
Electrocortical Activity ◽  
Fetal Breathing ◽  
Pregnant Ewe ◽  
Placental Extract

We have found previously that the infusion of a placental extract inhibits breathing induced by 100% O2 plus umbilical cord occlusion in the fetal sheep, suggesting that a placental factor is responsible for the inhibition of fetal breathing. To test whether this factor is specific to the placenta and whether it also inhibits spontaneous fetal breathing (occurring in the absence of cord occlusion), we administered extracts from the placenta, muscle and liver of the pregnant ewe, extracts of fetal liver, and Krebs solution to 16 chronically instrumented fetal sheep at 135 +/- 5 days of gestation. Infusions were made during low-voltage electrocortical activity, 5 to 15 min after a switch from high voltage, when breathing was well established. Within 90 s of the infusion of the placental extract in the carotid artery of the fetus, breathing decreased in 79% (33/42) of the experiments and was completely abolished in 71% (30/42) of them (P < 0.0001 compared with the other infusates). No apnoeas were observed with the Krebs solution (0/19) and the maternal muscle (0/20). Extracts of maternal and fetal liver abolished breathing in only 17% (4/23) and 21% (6/29) of the experiments respectively (NS compared with Krebs solution). There were no significant changes in blood gas tensions, pH, blood pressure and heart rate associated with the infusion of the extracts. The electrocortical activity (ECoG) switched from low to high voltage in 50% of the experiments using placental extract compared with 0% with Krebs solution and maternal muscle, and with 9% and 17% with maternal and fetal liver respectively (P < 0.005). Breathing output (integral of EMGdi x f) during and after the infusions significantly decreased only with the placental extract. These findings indicate the presence of a factor produced by the placenta which inhibits fetal breathing and may be responsible for the normal inhibition of breathing observed in fetal life.

Superoxide anion impairs Ca2+mobilization in cultured human nasal epithelial cells

1999 ◽  
Vol 277 (6) ◽  
pp. L1089-L1095
Author(s):  
Tetsuya Koyama ◽  
Masahiro Oike ◽  
Sohtaro Komiyama ◽  
Yushi Ito
Keyword(s):  
Superoxide Dismutase ◽  
Epithelial Cells ◽  
Superoxide Anion ◽  
Response Curve ◽  
Krebs Solution ◽  
Nasal Epithelial Cells ◽  
Human Nasal Epithelial Cells ◽  
Bath Application ◽  
Intracellular Ca ◽  
Concentration Response Curve

We examined the effects of superoxide anion ([Formula: see text]) on the intracellular Ca2+ concentration in cultured human nasal epithelial cells. The cells were exposed to[Formula: see text] by pretreatment with xanthine (X) and xanthine oxidase (XO); control cells were treated with X alone. When Ca2+-containing Krebs solution was reperfused in the thapsigargin-treated, store-depleted cells, reapplication-induced intracellular Ca2+ concentration elevation was significantly smaller in X/XO-treated cells than in the control cells, suggesting that [Formula: see text] impairs Ca2+ release-activated Ca2+ entry (CRAC). Bath application of ATP induced a steep Ca2+ transient in both control and X/XO-treated cells. However, the concentration-response curve of the ATP-induced Ca2+ transient was shifted to a higher concentration in X/XO-treated cells. The impairments of CRAC and ATP-induced Ca2+ transient induced by X/XO were reversed by superoxide dismutase. Furthermore, all these X/XO-induced effects were also observed in cells pretreated with pyrogallol, also an [Formula: see text] donor. These results indicate that [Formula: see text] impairs at least two mechanisms involved in Ca2+ mobilization in human nasal epithelial cells, i.e., CRAC and ATP-induced Ca2+ release.

APV-sensitive dorsal root afferent transmission to neonate rat sympathetic preganglionic neurons in vitro

1990 ◽  
Vol 64 (3) ◽  
pp. 991-999 ◽  
Author(s):  
E. Shen ◽  
N. Mo ◽  
N. J. Dun
Keyword(s):  
Receptor Antagonist ◽  
Dorsal Root ◽  
Resting Membrane Potential ◽  
Excitatory Postsynaptic Potential ◽  
Krebs Solution ◽  
Membrane Hyperpolarization ◽  
Sympathetic Preganglionic Neurons ◽  
Preganglionic Neurons ◽  
Stimulation Of

1. Intracellular recordings were made from antidromically identified sympathetic preganglionic neurons (SPNs) in transverse thoracolumbar spinal cord slices from neonate (12- to 22-day-old) rats. 2. Electrical stimulation of dorsal roots or dorsal root entry zone elicited in SPNs an excitatory postsynaptic potential (EPSP) or multiple EPSPs of varying latencies. The EPSP could be graded by varying the stimulus intensity and, on reaching the threshold, discharged an action potential. 3. The dorsal root-evoked EPSPs had a mean synaptic latency of 2.6 ms (range: 1.2-11 ms), suggesting a polysynaptic pathway. The EPSPs were characteristically slow in onset with a mean rise time and half-decay time of 8.3 and 23 ms, respectively. 4. At the resting membrane potential of -50 to -60 mV, the amplitude of EPSPs recorded in normal (1.3 mM Mg2+) Krebs solution was reduced by membrane hyperpolarization or depolarization. In Mg2(+)-free solution, EPSPs were potentiated and reached threshold for spike discharge. 5. The EPSPs were suppressed by the nonselective glutamate receptor antagonist kynurenic acid (0.1-0.5 mM) and by the N-methyl-D-aspartate (NMDA) receptor antagonists D-2-amino-5-phosphonovaleric acid (APV; 1-10 microM) and ketamine (5-10 microM), but not by the quisqualate (QA)/kainate (KA) receptor antagonist 6,7-dinitroquinoxaline-2,3-dione (DNQX, 1-10 microM). The latter depressed the EPSPs elicited by stimulation of lateral funiculus in the same SPNs. 6. NMDA applied by pressure elicited a depolarization in the SPNs. In normal Krebs solution the response was voltage dependent with the peak amplitude occurring around -60 mV; conditioning depolarization or hyperpolarization diminished the response.(ABSTRACT TRUNCATED AT 250 WORDS)

Noncholinergic vasodilator innervation in the feet of ducks

1979 ◽  
Vol 237 (2) ◽  
pp. H112-H117
Author(s):  
D. D. McGregor
Keyword(s):  
Electrical Stimulation ◽  
Nerve Stimulation ◽  
Anas Platyrhynchos ◽  
Gallus Domesticus ◽  
Krebs Solution ◽  
Vasomotor Responses ◽  
Pekin Ducks ◽  
Stimulation Of

Vasomotor responses to nerve stimulation were studied in the feet of Pekin ducks (Anas platyrhynchos) and domestic chickens (Gallus domesticus). The birds were killed and the feet isolated and perfused with a Krebs solution. Electrical stimulation of pedal nerves gave vasoconstrictor responses that were abolished by injecting guanethidine and by treating birds with reserpine. After guanethidine or reserpine, nerve stimulation resulted only in vasodilatation, which was unaffected by hexamethonium. Vasodilator responses to nerve stimulation were not blocked by hyoscine or atropine, which blocked responses to acetylcholine, nor by metiamide, which blocked vasodilatation in response to histamine. Responses to nerve stimulation were blocked by tetrodotoxin. Isoprenaline produced vasoconstriction that was blocked by phentolamine and also weak vasodilator responses that were antagonized by propranolol. It is concluded that the vasoconstrictor innervation is adrenergic. The identy of the vasodilator neurotransmitter is unknown; it is apparently not acetylcholine, a catecholamine, or histamine.

Transmembrane action potentials and contractions of human atrial muscle

1964 ◽  
Vol 206 (5) ◽  
pp. 1000-1014 ◽  
Author(s):  
William Sleator ◽  
Taisija De Gubareff
Keyword(s):  
Action Potentials ◽  
Krebs Solution ◽  
Duration Of Action ◽  
Atrial Muscle ◽  
Transmembrane Action Potentials ◽  
New Type ◽  
Two Phases ◽  
Low K ◽  
Type Of Behavior ◽  
High Phase

Transmembrane action potentials and contractions were recorded from pieces of human atrial muscle stimulated electrically in Krebs solution. These preparations exhibit a new type of behavior characterized by periodic "cycling" between two phases: high-phase contractions are two to eight times those in low phase, and action potentials have two or more spikes. The phenomenon can occur in a piece of any size, and is most likely at temperatures between 20 C and 33 C. Acetylcholine weakens contractions, reduces duration of action potential (AP) plateau, and usually abolishes double spikes and cycling; this suggests relatively low K+ permeability during the long low plateau. Epinephrine shortens the cycling period and makes low- and high-phase contractions more nearly equal; additional epinephrine leads to bizarre APs and spontaneous activity. This behavior of human atrial tissue reflects intrinsic capabilities of the cell membrane not previously observed in heart. General hypotheses are proposed to account for the double-spiked APs, for cycling, and for relations between the unique contraction patterns and AP configurations.

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