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PubMed1997

The use of sodium bicarbonate in oral hygiene products and practice.

Early dentifrices contained natural ingredients, mostly in coarse particle form, and were quite abrasive. Salts, either sodium chloride, sodium bicarbonate, or a mixture of both, have also been used for tooth cleaning because of their ready availability and low cost. Because of both their relatively low intrinsic hardness and their high solubility, another advantage is low abrasivity. Their biggest disadvantage is a salty, unpalatable taste. Many modern dentifrices that contain sodium bicarbonate, either as the sole abrasive or one of several, disguise the saltiness with flavoring and sweetening agents. An almost inverse relationship exists between the percentage of baking soda in a dentifrice and its abrasivity. Sodium bicarbonate has no anticaries activity per se but is compatible with fluoride. In high concentrations, sodium bicarbonate is bactericidal against most periodontal pathogens. Most clinical studies have not found significant differences in periodontal response to baking soda as compared with other commercial dentifrices, probably because of its rapid clearance from the gingival sulcus. Sodium bicarbonate may not be the "magic bullet" for curing dental diseases, but its safety (if ingested), low abrasivity, low cost, and compatibility with fluoride make it a consummate dentifrice ingredient.

Dental Plaque↗
PubMedDate not supplied

Distal tubule bicarbonate transport.

The superficial cortical distal tubule, accessible to in vivo micropuncture and microperfusion, has been the site of a considerable number of investigations. An important fraction of renal tubule bicarbonate reabsorption, about 8 to 9% of the filtered load of this ion in the rat, takes place in this segment. The present review addresses several aspects of bicarbonate transport by distal tubule. It includes the overall magnitude of bicarbonate reabsorption, as well as the most important methods used to measure this process. The acid-base transporters responsible for transmembrane and transepithelial bicarbonate transport are also discussed. This analysis is followed by a description of several important factors that regulate bicarbonate transport in distal tubule, including the role of carbonic anhydrase and potassium depletion, and finally the participation of peptide hormones, in particular angiotensin II and arginine vasopressin. The analysis of the role of these factors is centered on microperfusion studies and on the analysis of cellular function based on cell pH and calcium modulation in renal cells in culture.

Animals↗
PubMedDate not supplied

Bicarbonate stimulation of boar sperm motility via a protein kinase A-dependent pathway: between-cell and between-ejaculate differences are not due to deficiencies in protein kinase A activation.

Because poorly motile sperm samples can often be stimulated by treatments that increase intracellular levels of cyclic adenosine monophosphate (cAMP), it has been supposed that such samples are unable to maintain an adequate supply of the cyclic nucleotide with which to activate protein kinase A (PKA). To investigate this hypothesis, we incubated boar sperm samples with bicarbonate (a stimulator of adenylyl cyclase) and compared its effect with that of 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole 3',5'-cyclic monophosphothioate (cBIMPS, a highly permeable and stable cAMP analog). Videomicroscopy assessment of motility was followed by computer analysis of the sperm tracks to produce motility descriptor values for many individual cells in each sample, whence "cluster" analysis of these data identified groups of spermatozoa that differed in motility characteristics. Bicarbonate stimulation of motility was characterized by an increase in the linearity (LIN) and progressive velocity of part of the sperm population only. The size of this "fast linear" subpopulation varied considerably between ejaculates. However, treatment with cBIMPS did not induce significantly more "fast linear" sperm than treatment with bicarbonate. In further experiments investigating the role of protein kinases in motility control, bicarbonate stimulation was greatly inhibited by H89 (a specific inhibitor of PKA), whereas GF109203X and lavendustin A (inhibitors of protein kinase C [PKC] and protein tyrosine kinase [PTK], respectively) had essentially no effect. While inclusion of the protein phosphatase inhibitor calyculin stimulated motility, it failed to increase the overall percentage of "fast linear sperm" induced by bicarbonate. We conclude that intersperm and interejaculate differences in boar sperm motility are not due to inadequacy in cAMP supply or to ineffective PKA activity.

Animals↗
PubMedDate not supplied

Clinical experience with a new bicarbonate (25 mmol/L)/lactate (10 mmol/L) peritoneal dialysis solution.

OBJECTIVE: Physiological bicarbonate/lactate-based solutions may correct acidosis in a better way than standard lactate-based solutions. In this study, a new 25 mmol/L bicarbonate/10 mmol/L lactate peritoneal dialysis (PD) solution was compared with a standard 35 mmolL lactate solution. DESIGN: This was a prospective open label study. All patients had a 2-week baseline period using the standard lactate solution, followed by 8 weeks on the bicarbonate/ lactate solution and 2 weeks on the lactate-based solution. SETTING: Four Danish and four Spanish nephrology centers. PATIENTS: 40 well-dialyzed (creatinine clearance > 55 L/week/1.73 m2 body surface area) patients on continuous ambulatory PD. INTERVENTIONS: Blood samples were taken for biochemistry (including venous blood gases) at week -2, day 1, weeks 2, 4, and 8, and at follow-up. A physical examination, a peritoneal equilibration test (PET), and quality of life (K/DQOL), ultrafiltration, and adequacy assessments were performed at baseline and at week 8. Vital signs and other safety parameters were followed at each visit. Extraneal (Baxter Healthcare, Castlebar, Ireland) was used by all patients for the long dwell. MAIN OUTCOME MEASURE: Effect on the venous plasma bicarbonate level. RESULTS: Venous plasma bicarbonate levels rose from 24.4 mmol/L when patients were on the pure lactate to 26.1 mmol/L when using the bicarbonate/lactate solution (p < 0.001). When patients were using the bicarbonate/ lactate solution, 66% of values were maintained within the venous normal range of 24-30 mmol/L, versus 46.2% when patients were on the pure lactate solution (p < 0.001). There were no adverse findings with respect to clinical symptoms, vital signs, or physical examination. The PET and adequacy, ultrafiltration, and K/DQOL assessment results were unchanged. CONCLUSIONS: The new 25 mmol/L bicarbonate/ 10 mmol/L lactate solution provided better correction of acidosis than an equivalent 35 mmol/L standard lactate solution, without any safety issues.

Acidosis↗
PubMed1992

pH threshold for human duodenal bicarbonate secretion and diffusion of CO2.

Gastric acid enters the proximal duodenum both as free and buffered H+. The procedures in this study were threefold: (a) to determine the pH threshold for duodenal mucosal bicarbonate secretion, iso-osmolar citric acid (pH 2.5-4.0; H+, 1.1 mmol) was infused; (b) to examine the effect of varying acid loads (H+, 0.4-5.1 mmol), citric acid (pH 3.0) was perfused; and (c) to quantitate duodenal diffusion of CO2, citric acid (pH 5.0) gassed with CO2 (PCO2, 0-210 mm Hg) was tested. Basal bicarbonate secretion was similar on each test day, 230 mumol/cm.h. Citric acid at pH 2.5 and 3.0 increased bicarbonate output equally to about 560 mumol/cm.h (similar to 2 mmol of 100 mmol/L HCl); citric acid at pH 3.5 and 4.0 had no effect. Varying the acid load increased bicarbonate output similarly. Duodenal loss of CO2 was minimal (4%) with infusion of 50 mm Hg PCO2 and increased to approximately 25% (15 mm Hg/min) at higher PCO2 values. It is concluded that (a) the pH threshold for human duodenal mucosal bicarbonate secretion is 3.0; (b) a pH-sensitive, rather than an acid load-sensitive, regulatory process exists; and (c) CO2 loss plateaus at 15 mm Hg/min at a PCO2 of 200 mm Hg.

Adult↗
PubMed2006

[Significance of infusion of sodium bicarbonate in amniotic cavity under continuous internal fetal heart rate monitoring for management of fetal distress during labor].

OBJECTIVE: To investigate the effect of infusion of sodium bicarbonate in amniotic cavity and exchange of amniotic fluid for fetus with distress and acidosis. METHODS: The patients included 40 cases of oligohydramnios with mild and serious abnormality of fetal heart rate and amniotic fluid contamination of degree II or more during the labor. The 40 cases had exchange of amniotic fluid with infusion under continuous monitoring. Twenty of them had infusion with 5% sodium bicarbonate into amniotic cavity; the other 20 cases received 5% sodium bicarbonate intravenous in fusion. After the labor all the patients had test of arterial blood gas in umbilical cord and the fetuses were evaluated with Apgar score. RESULTS: (1) the effective rate was 88% in the group of infusion into amniotic cavity and 85% in the group of exchange of amniotic fluid. (2) The arterial blood pH, PO(2), HCO(3)(-), ABE, SBE in the group of amniotic cavity infusion with 5% sodium bicarbonate were all higher than group of IV infusion, however PCO(2) was significantly lower than the group of IV (P < 0.05). CONCLUSION: Infusion into amniotic cavity and exchange of amniotic fluid is effective therapy for fetal distress due to oligohydramnios and can prevent meconium aspiration syndrome; infusion of antacids medicine (5% sodium bicarbonate) into amniotic cavity is effective and safe therapy for fetus with acidosis.

Acidosis↗
PubMed1991

Short term study on relative merits of acetate and bicarbonate dialysis.

We did a double blind, crossover, prospective study comparing bicarbonate and acetate containing solutions in haemodialysis. Thirty stable patients with end stage renal disease on maintenance haemodialysis while awaiting a renal transplant were each studied on three dialysis with acetate and three with bicarbonate. Nine patients developed symptoms like headache, nausea, vomiting, giddiness, and malaise and developed hypotension during acetate dialysis and three patients during bicarbonate dialysis. There were symptoms during 16.66% of acetate dialysis sessions and 5.55% of bicarbonate dialysis sessions. (P less than 0.05). There was a statistically significant decrease in PaO2 and PaCO2 on acetate dialysis at 30 minutes after initiation of dialysis. There was no significant difference in weight loss on dialysis, or in blood pressure and correction of acidosis. We conclude that bicarbonate dialysis is better tolerated, but acetate intolerance is not a major problem since we use small surface area dialysers (0.8 M2).

Acetates↗
PubMed1976

Cyclic AMP and bicarbonate responses of the dog pancreas to vasoactive intestinal peptide (VIP) and secretion.

The effects of secretin (3 CU per kilogram) and vasoactive intestinal peptide (VIP; 8 mug per kilogram) on bicarbonate and cyclic AMP secretions in pancreatic juice (with pancreatic duct perfusion) and on pancreatic tissue cyclic AMP were investigated as a function of time in 13 anesthetized dogs. The peptides were given by rapid intravenous injection. Even 30 sec. after peptide administration, tissue cyclic AMP levels were elevated, reaching peak values within the first minute and a second peak at about 3 min. Bicarbonate and cyclic AMP secretions in pancreatic juice started with a lag of 1 min. after peptide injection. Following the injection of VIP, peak pancreatic response developed within the first 5 min. and the pancreatic response actually disappeared after 15 min., whereas secretion evoked by secretin was sustained for at least 30 min. The mean +/- S.D. observed maximal bicarbonate response to VIP (100 +/- 49 muEq./5 min.) was about one sixth of the maximum output following secretin (592 +/- 181 muEq./5 min.). Increases in pancreatic tissue and juice cyclic AMP caused by VIP were significant (p less than 0.05) at 1 and 4 min.; however, they were but moderate if compared with the rise achieved by secretin. The results presented confirm previous reports that VIP is a secretin-like partial agonist of pancreatic bicarbonate secretion and are compatible with the hypothesis that both secretin and VIP elicit canine pancreatic bicarbonate secretion via the second messenger system of cyclic AMP.

Animals↗
PubMedDate not supplied

[A comparative assessment of homeostasis and hemodynamics during the performance of bicarbonate and acetate hemodialysis].

The article deals with the comparative analysis of certain values of homeostasis and hemodynamics in 25 patients with chronic renal failure who were subjected to systematic bicarbonate and acetate hemodialysis. Comparative study of some values of homeostasis, hemodynamics and myocardial contractility in patients with chronic renal failure during hemodialysis with acetate and bicarbonate solutions showed the advantages of bicarbonate hemodialysis. During bicarbonate hemodialysis, in addition to the patients' good tolerance to the procedure, the correction of the disturbed homeostasis was more physiological on the one hand, and positive shifts occurred in the activity of the blood circulatory system on the other. The study showed the expediency of using bicarbonate hemodialysis in patients with chronic renal failure with individual intolerance to acetate solution, and with severe heart failure and metabolic acidosis.

Acetates↗
PubMed1977

Ionic flux across canine duodenum. Movement of bicarbonate.

Effect of isosmotic biocarbonate-rich solutions on the Brunner's gland area were studied by means of proximal duodenal explants in eight anesthetized dogs. Volume gain occurred with all instillates and varied indirectly with the concentration of the bicarbonate in the instilled solutions. Net bicarbonate gain occurred with instillate of 40 mEq./1.; net insorption occurred with instillates of higher bicarbonate concentration, the rate of which was dependent on the instillate concentration. Insorption of chloride occurred with the lower bicarbonate solutions and enterosorption occurred at higher concentrations. The modification of intraluminal bicarbonate by the proximal duodenal mucosa is important in the regulation of intraduodenal pH and abnormal function of this mechanism may play a role in the pathogenesis of duodenal ulceration because of incomplete hydrochloric acid neutralization.

Animals↗
PubMed1990

Effect of glucose on the kinetics of bicarbonate reabsorption in the early and middle proximal tubule.

1. The kinetics of bicarbonate reabsorption in the early (EPT) and middle proximal tubule (MPT) was studied in Munich Wistar rats by means of microperfusion techniques. 2. The early proximal tubule (EPT) had a higher capacity of reabsorbing bicarbonate than the middle segment. The calculated bicarbonate flow (JHCO3) was 4.47 nmol s-1 cm-2 in the EPT and 2.30 nmol s-1 cm-2 in the MPT, and the half time of injected bicarbonate (t/2) was less in the EPT (2.24 s) than in the MPT (5.20 s). 3. The presence of 20 mM glucose in the lumen led to a reduction in the velocity of tubular acidification in the EPT (3.11 s) and caused a decrease in JHCO3 in both segments (2.46 nmol s-1 cm-2 in the EPT and 1.64 nmol s-1 cm-2 in the MPT). 4. These alterations may be the result either of lumen-to-cell sodium gradient dissipation or electrical changes induced by sodium-glucose cotransport that may depolarize the basolateral membrane leading to intracellular alkalinization. This effect may then impair the Na+/H+ exchanger, thus decreasing bicarbonate reabsorption.

Absorption↗
PubMed1989

[Determination of gastric bicarbonate secretion in the human without acid suppression].

Gastric CO2/HCO3 was determined in absence of simultaneous inhibition of acid secretion by intra- and extragastric pCO2/pH measurements in 23 persons and calculated using the equation of Henderson-Hasselbalch. pCO2 was measured with use of a new electrode. The characteristics of the CO2 selective electrode membrane were tested in vitro. The CO2 selective membrane proved to be stable against 0.1 n HCl, gastric fluid with a pH of 1, and bile as well as mechanical irritations. 96.8 +/- 0.52% of given amounts of bicarbonate were detected in test fluids ranging in pH from 2.5-7.1. In gas and fluid, a linear relationship between given and measured bicarbonate of y = 0.97 x +1.03 with a correlation coefficient of 0.99 was observed. In vivo at pH less than 6, the intragastric pCO2 was significantly higher than that in venous blood. CO2 diffusion could be prevented by equilibration of intragastric pCO2 with venous pCO2. pCO2 was then measured in fluid as well as in reaspirated gas. Thus 94.6 +/- 8.8%, HCO3- that had been instilled intragastrically, could be detected. Without equilibration and resultant volume increase of the gas phase, bicarbonate secretion was 296.4 +/- 41.9 mumol/h under basal conditions and 520.8 +/- 252.8 mumol/h after acid stimulation. With equilibration, a bicarbonate secretion of 574.4 +/- 66.7 and 754.4 +/- 81.2 mumol/h was observed during basal and stimulated acid secretion. Our results indicate that bicarbonate measurements in absence of acid suppression require determination of CO2 in the fluid as well as in the gas phase.

Bicarbonates↗
PubMed1989

L-lactate for high-efficiency hemodialysis: feasibility studies and a randomized comparison with acetate and bicarbonate.

We evaluated the feasibility of using L-lactate as a base for hemodialysis. In one study, acid-base changes using 40 mM L- or DL-lactate were compared. In a second study, acid-base status using various amounts of L-lactate exclusively was studied. The third study compared symptoms and acid-base changes during 9 weeks of high-efficiency dialysis when using L-lactate, acetate, or bicarbonate as base. In the first study, plasma bicarbonate changes were equivalent with 40 mM L-lactate and 40 mM DL-lactate, but overall correction of acidosis appeared to be suboptimal. In the second study, when compared to a bicarbonate control period, correction of acidosis was reduced when using 40 mM L-lactate + 4 mM acetate solution, but increased when using a 46 mM L-lactate + 4 mM acetate solution. In the third study, correction of acidosis was comparable when using 42 mM L-lactate + 4 mM acetate, 39 mM acetate, or 35 mM HCO3 + 4 mM acetate. Whereas 46% +/- 12 (SEM) treatments "failed" because of symptoms when using acetate, the percentages of "failed" treatments were only 7% +/- 4.2 with L-lactate (p less than 0.05) and 11% +/- 4.2 with bicarbonate (p less than 0.05). The results suggest that L-lactate is a suitable dialysis solution base that is capable of correcting chronic uremic acidosis. During high-efficiency dialysis, the incidence of intradialytic symptoms with L-lactate is comparable to that with bicarbonate and less than that with acetate.

Acetates↗
PubMed1989

[Defense mechanisms of the gastroduodenal mucosa: the role of mucus and bicarbonate in the development of peptic ulcer].

The existing knowledge of the mucus and bicarbonate production of the gastroduodenal mucosa is reviewed. Mucus and bicarbonate are produced in the surface epithelium of both duodenum and ventricle. The production is regulated by neural stimuli, gastrointestinal hormones and local synthesis of prostaglandins. Several of the factors suspected of being of importance to the development of peptic ulcers also have a negative influence on the production of mucus and bicarbonate. This indicates that mucus and bicarbonate are important in the pathogenesis of peptic ulcer. Two newly registered so-called mucosaprotective anti-ulcer drugs (De-Nol, Succralfat) both exert positive influences on the production of mucus and bicarbonate.

Bicarbonates↗
PubMed1989

Origins of chloride and bicarbonate secretory defects in the cystic fibrosis pancreas, as suggested by pancreatic function studies on control and CF subjects with preserved pancreatic function.

Pancreatic function studies were performed under continuous intravenous stimulation with secretin and cholecystokinin (0.125 mu/kg/min) in 40 patients with CF who had no evidence of steatorrhea and 69 control subjects without CF, who also lacked evidence of steatorrhea. A total of 41 studies in CF patients and 74 in control subjects were analysed for trypsin, electrolyte, and water secretion. 51% of the CF and 51% of the control tests showed trypsin secretion responses between 1000 mu/kg/hr (the lower limit of the normal range) and 2695 mu/kg/hr, while 16.2% of the control tests exceeded this range. Secretion of water and electrolytes, including both chloride and bicarbonate, was significantly lower in the CF subjects when compared to the appropriate controls in the normal and subnormal trypsin output range. Chloride-bicarbonate ratios, although higher in subjects with evidence of pancreatic damage, were identical in CF and control studies. A specific ductal lesion in CF which altered the balance of acinar (predominately chloride) and ductal (predominately bicarbonate) secretion, or encouraged the equilibration of ductal fluid with plasma in the distal ducts, would increase chloride-bicarbonate ratios, as in the subjects with reduced trypsin secretion. Since this did not occur in the patients with normal function, our results suggest that chloride and bicarbonate secretions are impaired to a similar extent in CF, possibly through a dependence on the same phenotypic abnormality.

Bicarbonates↗
PubMed1985

A bicarbonate-dependent process inhibitable by disulfonic stilbenes and a Na+/H+ exchange mediate 22Na+ uptake into cultured bovine corneal endothelium.

22Na+ uptake into confluent monolayers of cultured bovine corneal endothelial cells was studied in the presence of ouabain (10(-4)M) to inhibit active sodium extrusion. In bicarbonate saline, uptake was reduced to a similar degree either by amiloride (10(-3)M) or by 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (SITS) (10(-3)M). A further reduction was obtained with SITS-pretreated cells in the presence of amiloride. SITS-sensitive uptake was further characterized in saline containing both ouabain (10(-4)M) and amiloride (10(-3)M). It was absolutely dependent on bicarbonate, which could not be substituted by other plasma membrane permeable buffers (50 mM acetate or 25 mM glycodiazine). It was a saturable function of both bicarbonate and sodium concentration. Half-maximal fluxes occurred between 3 and 7 mM HCO3 (at 151 mM Na) and between 35 and 60 mM Na (at 28 mM HCO3). Uptake into sodium-depleted cells was reduced as opposed to sodium-rich cells, and SITS-sensitive 22Na+ efflux out of 22Na+-loaded cells into sodium-free medium was less than efflux into sodium saline, indicating trans-stimulation by sodium. The amiloride-sensitive pathway was studied in the absence of bicarbonate to inhibit uptake via the SITS-sensitive pathway. 22Na+ uptake into sodium-depleted cells increased steeply with extracellular pH in the range between pH 6 and 8 and could be largely blocked by 10(-3), but not by 10(-5) M amiloride. It is concluded that bovine corneal endothelial cells possess at least two distinct pathways for sodium uptake, amiloride sensitive 22Na+ fluxes being mediated by a Na+/H+ antiport, while the SITS-sensitive process is probably identical to a bicarbonate-sodium cotransport system postulated earlier from electrophysiological studies.

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗
PubMed1987

Bicarbonate is a recycling substrate for cyanase.

Cyanase is an inducible enzyme in Escherichia coli that catalyzes bicarbonate-dependent decomposition of cyanate to ammonia and bicarbonate. Previous studies provided evidence that carbamate is an initial product and that the kinetic mechanism is rapid equilibrium random (bicarbonate serving as substrate as opposed to activator); the following mechanism was proposed (Anderson, P. M. (1980) Biochemistry 19, 2282-2888; Anderson, P. M., and Little, R. M. (1986) Biochemistry 25, 1621-1626). (formula; see text) Direct evidence for this mechanism was obtained in this study by 1) determining whether CO2 or HCO3- serves as substrate and is formed as product, 2) identifying the products formed from [14C]HCO3- and [14C] OCN-, 3) identifying the products formed from [13C] HCO3- and [12C]OCN- in the presence of [18O]H2O, and 4) determining whether 18O from [18O]HCO3- is incorporated into CO2 derived from OCN-. Bicarbonate (not CO2) is the substrate. Carbon dioxide (not HCO3-) is produced in stoichiometric amounts from both HCO3- and OCN-. 18O from [18O]H2O is not incorporated into CO2 formed from either HCO3- or OCN-. Oxygen-18 from [18O]HCO3- is incorporated into CO2 derived from OCN-. These results support the above mechanism, indicating that decomposition of cyanate catalyzed by cyanase is not a hydrolysis reaction and that bicarbonate functions as a recycling substrate.

Aminohydrolases↗
PubMed1987

Cardiovascular and acid-base effects of acetate and bicarbonate haemodialysis.

Cardiovascular and acid-base changes were studied in 18 adult haemodialysis patients during a single dialysis against acetate or bicarbonate dialysate. Tachycardia was significantly greater with acetate but, otherwise, blood pressure and peripheral resistance fell and cardiac output increased to a similar degree with the two types of dialysate. Arterial PCO2 increased with bicarbonate and fell slightly with acetate, while hypoxaemia was significantly worse during acetate dialysis. Arterial acetate concentrations increased in 2 of 12 patients during bicarbonate dialysis. No differences in patient symptomatology or hypotensive episodes were noted with acetate or bicarbonate. Any beneficial effects of bicarbonate dialysis are more likely to be related to preservation of arterial PO2 than to the absence of adverse cardiovascular effects of acetate.

Acetates↗