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PubMed1995

Mercury uptake by primary cultures of rat renal cortical epithelial cells. II. Effects of pH, halide ions, and alkali metal ions.

The effects of pH, halide ions, and alkali metal ions on the uptake of inorganic mercury (Hg) were investigated in confluent primary cultures of rat renal cortical epithelial cells. The cells were incubated with 1 microM Hg in phosphate buffer at pH 5.5, 6.4, or 7.4 for 30 min at 37 degrees C. Incubation of cells at pH 5.5 resulted in a 22% increase in total Hg accumulation over those cells that were incubated at pH 7.4. Almost all of this increase was accounted for in the membrane fraction. In contrast, there was a 33% reduction in internalized Hg in cells incubated at pH 5.5. This may be explained by the conversion of hydroxide forms of Hg (Hg(OH)Cl and Hg(OH)2) to the chloride forms (HgCl2, HgCl3-, and HgCl4(2-) at a lower pH (decreased OH-) condition. In the presence of halide ions, the cells internalized Hg in the relative order of affinity of the halide ions for Hg2+ (i.e., F- < Cl- < Br- < I-). Br- and I- resulted in a 67 and 142% increase in internalized Hg over that by Cl-. The relatively high membrane binding and internalization of Hg in the presence of Br- and I- was possibly due to the formation of highly lipophilic complexes of Hg (i.e., HgBr2 and HgI2). The replacement of NaCl in the incubation medium by KCl caused a 36% decrease in internalized Hg. LiCl had a similar effect on the internalization of Hg. The above results suggest that in rat renal proximal tubules Hg uptake involves Na(+)- and H(+)-dependent mechanisms.

Animals↗
PubMed1985

Acute oral alkali citrate load in healthy humans--response of blood and urinary citrate, mineral metabolism, and factors related to stone formation.

In ten healthy volunteers (male/female = 5/5) the effects of two doses (2.5 and 5.0 g) of orally ingested alkali citrate (AC) on serum citrate, variables of mineral metabolism in serum, the urinary excretion of citrate, sodium and minerals were studied and compared with the effects of an oral vehicle load. Also, phosphate crystalluria and the supersaturation of several stone forming phases in urine were evaluated under all loads. The data allow to conclude that 1) the rise in serum citrate may result from citrate absorbed intestinally under AC; 2) systemic metabolic alkalosis is not detectable with the chosen AC doses but may be reflected by the more alkaline urinary pH and a higher citrate excretion; 3) mineral metabolism, serum ionized calcium, parathormone, calcitonin and urinary cyclic AMP included, are more or less stable under acute loads of AC; 4) postprandial phosphate crystalluria is more pronounced with increasing AC, but despite this the direct correlation with the supersaturation of hydroxyapatite is progressively weakened with both doses AC suggesting that the inhibitory effects of this drug may dominate over its effects upon initiation of precipitation.

Adult↗
PubMed1988

Renal hypercalciuria and metabolic acidosis associated with medullary sponge kidney: effect of alkali therapy.

Sixteen patients with medullary sponge kidney (MSK) and renal stones underwent evaluation of calcium metabolism and acid base balance. Six normal subjects and eight patients with non-MSK absorptive hypercalciuria served as control. Nine (56%) were hypercalciuric and seven (44%) were normocalciuric (N-MSK). Hypercalciuria was divided into absorptive (AH-MSK, n = 2) and renal leak hyerpcalciuria (RH-MSK, n = 7). The mean of minimal urine pH of RH-MSK group (5.28 +/- 0.09 (SE] was significantly higher than that of normal control (4.78 +/- 0.12) and of non-MSK AH (4.80 +/- 0.6) during acute acid challenge. The mean of the arterial blood HCO3 concentration of RH-MSK group was significantly lower than that of two control groups. The urine calcium and a frequency of stone passage were decreased significantly after alkali treatment in RH-MSK.

Acid-Base Equilibrium↗
PubMed1988

Assignment of the human fast skeletal muscle myosin alkali light chains gene (MLC1F/MLC3F) to 2q 32.1-2qter.

A DNA probe derived from a mouse intronless pseudogene including coding regions for the myosin fast skeletal muscle alkali light chains, MLC1F/MLC3F (suggested HGM symbol, MYL1), was tested on a panel of 25 independent man-rodent somatic cell hybrids in order to assign the human MLC1F/MLC3F gene to a human chromosome. A 3.7-kb TaqI human fragment was found to correlate with the presence of chromosome 2 in the hybrids, characterized both by cytogenetic analysis and reference enzyme markers. A regional assignment to 2q32.1-qter was possible using hybrids whose human parental strains bore a reciprocal translocation t(X;2) (p22;q32.1). The fact that IDH1 and the MLC1F/MLC3F gene are closely linked on chromosome 1 in the mouse and map to the same region of human chromosome 2 in man indicates, that these chromosomes have a conserved region of homology between them and that the human 3.7-kb TaqI fragment corresponds indeed to a functional gene.

Animals↗
PubMed1975

Alkali and acid burns of the rabbit eye: measurement of aqueous flow by means of intravenously injected Na-125 I and Na-131I.

Rabbit eyes were burned either with 1N NaOH or 1 N HC1. On the fifth day following the injury, aqueous humour flow was determined according to a method originally described by Becker (1962), using intravenous injection of Na-125I and Na-131I in different time intervals. In alkali-burned eyes the main finding was stoppage of the aqueous humour flow, probably due to obstruction of outflow channels. In acid-burned eyes the significantly elevated diffusion out of the eye was probably caused by altered function of the highly irritated and hyperemic iris. Results confirmed the previous findings achieved by the rate of disappearence of 14-C-glucose injected into the anterior chamber of the burned eyes.

Animals↗
PubMed1977

An alkali-soluble polysaccharide from the cell walls of Coprinus lagopus.

An alkali-soluble polysaccharide was isolated from the purified mycelial walls of Coprinus lagopus. The hydrolysis products, optical rotation, and infrared spectrum indicate a beta-glucan. Hydrolysis of the glucan after permethylation gave only 2,3,4,6-tetra-, 2,4,6-tri-, and 2,4-di-O-methyl-D-glucose. These methylated sugars and their relative quantities reveal that the glucan is a polysaccharide containing beta-1,3-linked glucose units with about 14% of the sugars having 1,6-linked branch points. Partial hydrolysis of the product derived from Smith degradation of the glucan released laminaribiose and gentiobiose suggesting that the branches are generally longer than a single glucose unit.

Agaricales↗
PubMed1989

Histochemical study of alkali-burned rabbit anterior eye segment in which severe lesions were prevented by aprotinin treatment.

Activities of different enzymes (acid glycosidases, phosphatases, Na+ - K+ -dependent ATPase, proteases, dehydrogenases) and acid glycosaminoglycans were studied by histochemical methods in sections of rabbit anterior eye segments after experimental alkali burn and treatment with aprotinin, an inhibitor of plasmin and other serine proteinases. Solutions of sodium hydroxide (0.25-1.0 M) were applied on corneas using 12-mm-diameter plastic tube for 15-60 s. After wiping with cotton and rinsing with tap water aprotinin solutions were applied in saline (in experimental animals) and saline (in control animals) dropwise in 12-h intervals for a month. Within the first two weeks aprotinin was used at a concentration of 5000 IU/ml. During the subsequent two weeks the aprotinin concentration was reduced to 2500 IU/ml. Striking differences in enzyme activities and in the healing between treated and untreated eyes were found. Without aprotinin, ulcers developed in most corneas within 3 weeks and plasmin was regularly demonstrated in tears and in the aqueous. When aprotinin treatment was started within 24 h after the burn, the number of enzymatically active inflammatory cells was significantly lower, not only in the cornea itself but also in the whole anterior eye segment. With aprotinin treatment no ulcerations and no plasmin in tears and the aqueous were observed and the corneas healed within a month. The healing process started from the zone of enzymatically activated corneal cells in the unburned zone at the corneal periphery. In the regenerating epithelium and endothelium high activities of Na+ -K+ -dependent ATPase, gamma-glutamyltransferase, lactate and succinate dehydrogenases appeared very soon.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid Phosphatase↗
PubMed1975

Alkali burns of the rabbit cornea. I. A histochemical study of beta-glucuronidase, beta-galactosidase and N-acetyl-beta-D-glucosaminidase.

In alkali burned rabbit corneas activities of beta-glucuronidase, N-acetyl-beta-D-glucosaminidase and acid beta-galactosidase were studied histochemically in various time intervals after the traumatization. The technic with semipermeable membranes was employed. Within four days after the injury enzyme activities in the traumatized area were almost lacking. The corresponding activities in the unaffected part of the cornea were within the norm. On the 7th day enzyme activities were on an increase (but still subnormal) in the traumatized area. This area was surrounded by a zone of keratocytes with high levels of enzyme activities. This was particularly remarkable in keratocytes subjacent to the epithelium. The activation of all enzymes studied was present in the basal layer of the epithelium and in the endothelium as well. On the 14th day enzyme activities in the traumatized area were nearly restored and on the 32nd day they could not be distinguished from the normal cornea. Beta-galactosidase displayed a relatively maximal increase in the activity of all enzymes investigated.

Acetylglucosaminidase↗
PubMed1975

Alkali burns of the rabbit cornea. II. A histochemical study of glycosaminoglycans.

In alkali burned rabbit cornea the stainability of glycosaminoglycans in cold microtome setions was investigated. Staining by Alcian blue in 3% acetic acid, Alcian blue in various MgCl2 concentration and toluidine blue (pH 4.5) was employed. From the 1st to the 4th experimental day the intensity of reactions was decreased. This is most probably due to an increased hydration of the corneal stroma. On the 7th day hydration was markedly suppressed and reached nearly the normal level. In this time interval a decreased stainability of glycosaminoglycans was seen accompanied by a complete loss of staining in the marginal zone. On the 14th day the stainability in the traumatized area began to restore and in the marginal zone appeared. On the 32nd day the staining intensity of both areas was normalised, however when lower concentrations of MgCl2 were used; in the presence of higher concentrations of MgCl2 the decreased staining intensity persisted and points to a lower sulfatation of glycosaminoglycans. This was particularly remarkable in the area bordering the injured zone. This decrease runs parallel to the increased activities of acid glycosidases (especially of acid beta-galactosidase) which were reported previously.

Alcian Blue↗
PubMed1985

The same myosin alkali light chain gene is expressed in adult cardiac atria and in fetal skeletal muscle.

We have isolated from a cDNA library constructed using mouse cardiac mRNA sequences, a clone (pC6) homologous to part of the mRNA encoding the myosin alkali light chain MLC1A from adult mouse atria. This sequence also hybridizes to mRNA encoding the fetal light chain form MLC1emb expressed in both fused myotubes in culture and in 18 day fetal skeletal muscle. These mRNA sequences are indistinguishable from the MLC1A messenger both on the basis of size and of their thermal stability of hybridization. In vitro translation of mRNA selected by hybridization with pC6 results in a protein that comigrates with the fetal MLC1emb isoform, and two-dimensional gel electrophoresis of adult atrial and fetal skeletal muscle proteins shows MLC1A and MLC1emb to be indistinguishable in the mouse. Southern blot hybridization of clone pC6 to mouse genomic DNA and the analysis of restriction fragment length polymorphisms between different mouse species demonstrates the presence of a single hybridizing locus in the mouse genome. These data provide strong evidence that the atrial MLC1A and fetal skeletal MLC1emb isoform are encoded by the same gene and by the same mRNA and are thus identical proteins.

Animals↗
PubMed1987

Ion permeation through single channels activated by acetylcholine in denervated toad sartorius skeletal muscle fibers: effects of alkali cations.

The gigaohm seal technique was used to study ion permeation through acetylcholine-activated channels in cell-attached patches of the extrajunctional membrane of chronically denervated, enzyme-treated cells from the sartorius muscle of the toad Bufo marinus. The most frequently occurring channel type (greater than 95% of channel openings), provisionally classified as 'extrajunctional,' had a chord conductance of approximately 25 pS under normal conditions (-70 mV, 11 degrees C, Normal Toad Ringer's). The less frequently observed channel type (less than 5% of channel openings), classified as a 'junctional' type, had a conductance of 35 pS under the same conditions, and a similar null potential. In many patches, a small percentage (usually less than 2%) of openings of the extrajunctional channel displayed a lower conductance state. The shape of the I-V curves obtained for the extrajunctional channel depended on the predominant extracellular cation. For Cs and K, the I-V curves were essentially linear over the voltage range +50 to -150 mV across the patch, suggesting that the potential independent component of the energy profile within the channel was symmetrical. For Li, the I-V curve was very nonlinear, displaying a significant sublinearity at hyperpolarized potentials. Both an electrodiffusion and a symmetrical uniform four-barrier, three-site rate-theory model provided reasonable fits to the data, whereas symmetrical two-barrier, single-site rate-theory models did not. For the alkali cations examined, the relative permeability sequence was PCs greater than PK greater than PNa greater than PLi--a "proportional" selectivity sequence. This was different from the single channel conductance sequence which was found to be gamma K greater than gamma Cs greater than gamma Na greater than gamma Li implying that ions do not move independently through the channel. The relative binding constant sequence for the channel sites was found to be a "polarizability" sequence, i.e., KLi greater than KCs greater than KNa greater than KK. There was an inverse relationship between the relative binding constant and the relative mobility for the cations examined. Under conditions when the single-channel conductance was relatively high, the conductance at depolarized potentials was lower than that predicted by both electrodiffusion and rate theory models, suggesting that there was a rate-limiting access step for ions, from the intracellular compartment into the channel.

Acetylcholine↗
PubMed1986

Transport of alkali cations through thin lipid membranes by (222)C10-cryptand, an ionizable mobile carrier.

The kinetics of K+ and Na+ transport across the membrane of large unilamellar vesicles (L.U.V.) were compared at two pH's, with two carriers: (222)C10-cryptand (diaza-1,10-decyl-5-hexaoxa-4,7,13,16,21,24-bicyclo[8.8.8.]+ ++hexacosane) and valinomcyin, i.e. an ionizable macrobicyclic amino polyether and a neutral macrocyclic antibiotic. The rate of cation transport by (222)C10 saturated as cation and carrier concentrations rose. The apparent affinity of (222)C10 for K+ was higher and less pH dependent than that for Na+ but resembled the affinity of valinomycin for K+. The efficiency of (222)C10 transport of K+ decreased as the pH fell and the carrier concentration rose, and was about ten times lower than that of valinomycin. Noncompetitive K+/Na+ transport selectivity of (222)C10 decreased as pH, and cation and carrier concentrations rose, and was lower than that of valinomycin. Transport of alkali cations by (222)C10 and valinomycin was noncooperative. Reaction orders in cation n(S) and carrier m(M) varied with the type of cation and carrier and were almost independent of pH; n(S) and m(M) were not respectively dependent on carrier or cation concentrations. The apparent estimated constants for cation translocation by (222)C10 were higher in the presence of Na+ than of K+ due to higher carrier saturation by K+, and decreased as pH and carrier concentration increased. Equilibrium potential was independent of the nature of carrier and transported cation. Results are discussed in terms of the structural, physiocochemical and electrical characteristics of carriers and complexes.

Bridged Bicyclo Compounds↗
PubMed1995

Neural influences on human esophageal and salivary alkali secretion.

Esophageal secretion HCO3- ions occurs in opossum and man and may contribute to mucosal defense. Using a perfusion technique, neuroregulatory influences on esophageal and salivary HCO3- secretion were investigated in 24 healthy human subjects. The sight and smell of food increased median salivary HCO3- output from 424 to 573 mumol/15 min (P = 0.014), without significantly altering esophageal HCO3- secretion (74-105 mumol/15 min, P = 0.24). Atropine reduced both salivary (610 to 68, 17, 10, and 3 mumol/15 min in successive periods; P < 0.028) and esophageal HCO3- output (108 to 78, 35, 18, and 7 mumol/10 cm/15 min; P < 0.028, respectively. Following atropinization, cholinergic stimulation failed to increase salivary secretion but did "unmask" a small rise in esophageal alkali output (7 to 27 mumol/10 cm/15 min, P = 0.036), implicating a noncholinergic mechanism. Cold-induced pain activated sympathetic reflexes and reduced esophageal HCO3- output (91 to 64 mumol/10 cm/15 min, P = 0.041) without influencing salivary secretion. These observations support a role for the autonomic nervous system in modulating human esophageal and salivary HCO3- secretion.

Adolescent↗
PubMed1998

Influence of alkali-treated cornsteep liquor containing medium on protein A production by Staphylococcus aureus.

Staphylococcus aureus cultivated in liquid media containing untreated cornsteep liquor (CSL) and alkali-treated CSL produced similar biomass yields (6.5-6.9 g/L). However, contents of protein A in the biomass was 0.5% and 1.56% for untreated CSL and treated CSL, respectively. Addition of treated CSL at 20 g/L achieved optimal enhancement of protein A production (0.11 g/L). Probable factors associated in treated CSL for the enhanced protein A production are discussed.

Culture Media↗
PubMed2006

Exploration of yeast alkali metal cation/H+ antiporters: sequence and structure comparison.

The Saccharomyces cerevisiae genome contains three genes encoding alkali metal cation/H+ antiporters (Nha1p, Nhx1p, Kha1p) that differ in cell localization, substrate specificity and physiological function. Systematic genome sequencing of other yeast species revealed highly conserved homologous ORFs in all of them. We compared the yeast sequences both at DNA and protein levels. The subfamily of yeast endosomal/prevacuolar Nhx1 antiporters is closely related to mammalian plasma membrane NHE proteins and to both plasma membrane and vacuolar plant antiporters. The high sequence conservation within this subfamily of yeast antiporters suggests that Nhx1p is of great importance in cell physiology. Yeast Kha1 proteins probably belong to the same subfamily as bacterial antiporters, whereas Nhal proteins form a distinct subfamily.

Amino Acid Sequence↗
PubMed2001

[Low alkali-hydroxide content in soda limes does not lead to reduction of compound A formation from sevoflurane during low-flow anesthesia].

The alkali hydroxide content in soda lime induces Compound A formation from Sevoflurane (Sevo). This study was designed to answer the question if the use of potassium hydroxide-free Soda Lime (SL) would lead to lower Compound A levels as compared to Sodasorb (SO). A total of 30 patients scheduled for elective laparoscopic cholecystectomy received Sevo anaesthesia under low-flow conditions (0.8 l/min fresh gas flow). Each absorbent was used in 15 patients, but 3 patients of the SO group were excluded due to technical problems with Compound A analysis. Hemodynamic parameters, parameters of ventilation and gas concentrations were documented. Compound A concentrations were measured by gas chromatography from gas samples before Sevo application and 20, 40, 60, 90 and 120 min after low-flow start. Mean endtidal Sevo concentrations were 1.94 +/- 0.17 (SO) and 1.97 +/- 0.15 (SL) vol %, the total anaesthetic exposition was 1.52 +/- 0.36 (SO) and 1.64 +/- 0.47 (SL) MAC-h (n.s). The maximum Compound A concentration was significantly higher in SL group (19.6 +/- 2.8 vs. 11.7 +/- 4.1 ppm, p < 0.001). Therefore, elimination of potassium hydroxide from carbon dioxide absorbents alone did not lead to a reduction of Compound A formation during low-flow anaesthesia.

Anesthesia, Inhalation↗
PubMed2001

Modification of anomalous swelling in multilamellar vesicles induced by alkali halide salts.

By use of small-angle X-ray scattering it is shown that addition of alkali halide salts in small amounts (0-200 mM) shifts the repeat spacing in multilamellar DC13PC vesicles and alters the anomalous swelling behaviour close to the main transition. Both effects follow the Hofmeister series of the ions. We suggest that the shift of repeat spacing can be explained by ion effects on the van der Waals attractive forces between the membranes and on the decay length of the repulsive hydration force. The anomalous swelling is explained in terms of a critical unbinding of the membranes. The proximity of the critical temperature of the unbinding to the main transition temperature can be tuned by varying the concentration and type of salt in the sample.

Ions↗