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PubMed1984

The effects of sodium bicarbonate on brain blood flow, brain water content, and blood-brain barrier in the neonatal dog.

To explore the relationship between cerebral hemorrhage in the newborn and administration of sodium bicarbonate, we gave a standard dose of sodium bicarbonate (5 mEq/kg) to neonatal dogs and then assessed changes in cerebral blood flow, brain water content, and the blood-brain barrier. This dose of sodium bicarbonate produced no increase in blood pressure or cerebral blood flow and no alteration in blood-brain barrier. However, infusion of sodium bicarbonate did cause hyperosmolality and hypernatremia and a significant decrease in brain water content. Cerebral hemorrhage in the neonate associated with infusions of sodium bicarbonate may be related to shifts in brain water rather than to changes in blood pressure or cerebral blood flow.

Acid-Base Equilibrium↗
PubMed1983

Sodium bicarbonate therapy in severe diabetic ketoacidosis.

Rates of recovery of plasma glucose and bicarbonate levels, arterial pH, and level of consciousness were determined in a retrospective analysis of 95 episodes of severe diabetic ketoacidosis in patients treated with conventional regimens including low-dose insulin, saline, and potassium administration. No significant differences were found between 73 episodes in 52 patients treated with sodium bicarbonate and 22 episodes in 21 patients not undergoing such treatment. In view of these observations, the potential hazards of sodium bicarbonate replacement therapy, and the fact that sodium bicarbonate is still frequently given, the use of intravenous sodium bicarbonate treatment in patients with severe diabetic ketoacidosis requires reevaluation.

Acid-Base Equilibrium↗
PubMed1987

Stimulation of partially purified adenylate cyclase from bull sperm by bicarbonate.

Solubilized and partially purified adenylate cyclase from bull sperm was found to be specifically activated (up to 6-fold) by sodium bicarbonate (NaHCO3) and to a lesser extent by NaNO3. Other sodium salts were either ineffective (e.g. NaCOOH) or inhibitory (e.g. NaHSO3, NaHSO4 and Na2B4O7). Stimulation by NaHCO3 was dose-dependent in the range of 0-40 mM and was greater when enzyme activity was assayed in the presence of magnesium as compared with manganese ions. Bicarbonate seems to affect maximal enzyme velocity (Vmax) and has no effect on the Km of adenylate cyclase for Mn-ATP. Stimulation of adenylate cyclase by NaHCO3 coincided with the elution pattern of the enzyme as recorded following chromatography on DEAE-cellulose or gel filtration on BioGel P-100. These results suggest that in the course of stimulation of sperm adenylate cyclase, bicarbonate is likely to interact directly with the enzyme. Furthermore, this intrinsic and unique property of sperm adenylate cyclase may explain results reported by others on the stimulation of cAMP production by bicarbonate in intact and broken sperm preparations and suggest a biochemical basis for enhanced sperm motility associated with high bicarbonate concentrations.

Adenylyl Cyclases↗
PubMed1992

Effects of different dosages and modes of sodium bicarbonate administration during cardiopulmonary resuscitation.

Systemic acidosis occurs during cardiac arrest and cardiopulmonary resuscitation (CPR). The present study investigated the effect of different modes of sodium bicarbonate administration on blood gas parameters during CPR. Arterial and venous blood gases were obtained during 10 minutes of CPR which was preceded by 3 minutes of unassisted ventricular fibrillation in 36 dogs. Following 1 minute of CPR, the animals received one of four treatments in a randomized and blinded manner: normal saline (NS), sodium bicarbonate bolus dose 1 mEq/kg (B), sodium bicarbonate continuous infusion 0.1 mEq/kg/min (I), and sodium bicarbonate bolus dose (0.5 mEq/kg) plus continuous infusion 0.1 mEq/kg/min (L+I). Eleven dogs completed NS, 8 B, 8 I, and 9 L+I protocol. Following NS infusion, both arterial and venous pH declined consistently over time. Significant differences compared with NS treatment in venous pH were observed at 12 minutes of ventricular fibrillation (L+I, 7.27 +/- 0.05; NS, 7.15 +/- 0.05; B, 7.20 +/- 0.05; I, 7.24 +/- 0.04, each bicarbonate treatment versus NS, and L+I versus B, (P < .05). The B group had an elevated venous PCO2 (mm Hg) concentration following 6 minutes of ventricular fibrillation compared with NS, L+I, and I groups (81 +/- 14 versus 69 +/- 10 versus 68 +/- 10 versus 71 +/- 8, respectively, (P = .07). Arterial pH and PCO2 values showed a similar trend as the venous data with the L+I group demonstrating arterial alkalosis (pH > 7.45) at 12 minutes of ventricular fibrillation.(ABSTRACT TRUNCATED AT 250 WORDS)

Acidosis↗
PubMed1991

Effects of dichloroacetate and bicarbonate on haemodynamic parameters in healthy volunteers.

1. It has been shown that sodium bicarbonate has no effect or could even be detrimental in various forms of metabolic acidosis. Dichloroacetate, a stimulator of the pyruvate dehydrogenase complex, might offer an alternative treatment. The present study therefore examines the metabolic and haemodynamic effects of dichloroacetate and sodium bicarbonate in healthy volunteers. 2. On 2 different days, sodium dichloroacetate (50 mg/kg body weight) or sodium bicarbonate (1.5 mmol/kg body weight) was given intravenously as a single bolus in 10 healthy volunteers. Haemodynamic parameters were measured using a microprocessor-controlled system. Measurements were performed before and 30 and 60 min after infusion. 3. After administration of dichloroacetate, cardiac index increased from 2.3 +/- 0.03 to 2.7 +/- 0.1 1 min-1 m-2 (P less than 0.05), peripheral vascular resistance decreased from 266 +/- 9.7 to 240 +/- 1.7 kPa s l-1 (2662 +/- 97 to 2398 +/- 169 dyn s cm-5, P less than 0.05), oxygen availability increased from 442 +/- 16 to 535 +/- 30 ml min-1 m-2 (P less than 0.05) and serum lactate concentration fell from 1.4 +/- 0.14 to 0.6 +/- 0.1 mmol/l (P less than 0.05). With infusion of sodium bicarbonate there were no significant effects on any of these variables. 4. Our results show that dichloroacetate administered intravenously reduces the serum lactate concentration. The main effects of dichloroacetate itself are on the haemodynamic variables. Dichloroacetate increases cardiac index and oxygen availability and decreases peripheral vascular resistance, whereas sodium bicarbonate has no effect on haemodynamic or metabolic parameters. These data give some further insights in the actions of dichloroacetate and support the use of dichloroacetate as alternative therapy in various forms of metabolic acidosis.

Adult↗
PubMed2006

Relationship between bicarbonate retention and bone characteristics in broiler chickens.

Determination of the bicarbonate retention factor (BRF) is an important step during development of the indicator amino acid oxidation technique for use in a new model. A series of 4-h oxidation experiments were performed to determine the BRF of broilers aged 7, 14, 21, 28, 35, and 42 d using 4 birds per age group. A priming dose of 1.2 microCi of NaH(14)CO(3), followed by eight half-hourly doses of 1 microCi of NaH(14)CO(3) were given orally to each of 4 birds per age. The percentage of (14)C dose expired by the bird at a steady state was measured. These birds, as well as 12 additional birds matched for age and BW, were killed, and femur bone mineral density was measured by quantitative computed tomography to determine the relationship between bone development and bicarbonate retention at each age. There was a correlation (r = 0.50; P < 0.05) between total cross-sectional femur bone mineral density and bicarbonate retention at each age. A prediction equation (Y = 6.95 x 10(-2)X - 3.51 x 10(-5)X(2) + 27.58; P < 0.0001, R(2) = 0.79) where Y = bicarbonate retention and X = BW was generated to predict Y as a function of X. Bicarbonate retention values peaked at 28 d, during the stage of the most rapid bone deposition and the highest growth rate. A constant BRF was found from 1,900 to 2,700 g of BW of 35.15 +/- 1.095% (mean +/- SEM). This retention factor will allow the accurate correction of oxidation of (14)C-labeled substrates in broilers of different ages and BW in future indicator amino acid oxidation studies.

Aging↗
PubMed1986

The effect of sodium bicarbonate versus aluminum-magnesium hydroxide on postprandial gastric acid in duodenal ulcer patients.

When ingested 1 hour after a meal, conventional liquid antacids have a buffering effect of approximately 2 hours, while in the fasting state their effect is brief, lasting less than 1 hour. We tested the hypothesis that equal doses of antacid, one water soluble (sodium bicarbonate) and the other water insoluble (aluminum hydroxide plus magnesium hydroxide, MaaloxR), would have similar durations of postprandial buffering if the water soluble antacid regenerates the particulate protein buffer of the meal that leaves the stomach more slowly than liquids. Tests were conducted in random order on three separate days in 10 patients with duodenal ulcer. The effects of 30 ml of 2.39 M sodium bicarbonate (6.17 g, about 1 teaspoonful), the aluminum-magnesium antacid, each equivalent to 71.7 mmol of in vitro buffer, and water as a control on pH, hydrogen ion activity, and titratable acidity were compared. Thirty milliliters of each was swallowed 1 and 3 hours after ingestion of a standard solid plus liquid. Compared to the water control each dose of sodium bicarbonate significantly increased intragastric pH and decreased hydrogen ion activity and titratable acidity for only 1 hour. Each dose of the aluminum-magnesium antacid significantly buffered intragastric contents for 2 hours. These findings indicate that sodium bicarbonate transiently buffers postprandial intragastric contents. Therefore, sodium bicarbonate fails to reconstitute the protein buffer of the meal effectively, and the observations suggest that it leaves the stomach rapidly with the liquid phase of the meal. However, the water insoluble, aluminum-magnesium antacid has a longer duration of buffering, probably because it leaves the stomach more slowly, largely with the solid portion of the meal.

Adult↗
PubMed1986

Combination treatment with ranitidine and sodium bicarbonate prior to obstetric anaesthesia.

The gastric pH and volume were measured in 175 patients undergoing elective, and 313 undergoing emergency, obstetric procedures. Ranitidine 150 mg was administered orally every 6 hours in labour and at least 2 hours before elective Caesarean section. Patients received 20 ml of 8.4% sodium bicarbonate orally immediately prior to induction of anaesthesia. The combination of ranitidine and sodium bicarbonate produced marked alkalinisation of gastric contents (mean pH 8.9). The administration of sodium bicarbonate pre-operatively in patients who received ranitidine less than 2 hours before operation led to satisfactory elevation of gastric pH. Only four patients had a gastric pH less than 2.5, one patient refused any medication, two received only ranitidine and one patient had a long interval from administration of bicarbonate to aspiration of gastric contents. Gastric volumes were high in labouring patients (mean 84 ml) despite administration of ranitidine. The effectiveness of sodium bicarbonate as a single dose antacid therapy prior to obstetric anaesthesia requires further study.

Anesthesia, General↗
PubMed1991

The addition of sodium bicarbonate to prilocaine solution during i.v. regional anesthesia.

A comparison of plain prilocaine and bicarbonated prilocaine in intravenous regional anesthesia was studied in 30 patients undergoing upper extremity surgery. The patients were divided into two groups: one group was given anesthesia in the form of 1% prilocaine and the other group was given 1% prilocaine plus sodium bicarbonate. The onset of analgesia and anesthesia and recovery from analgesia and anesthesia were investigated in both groups. Bicarbonated prilocaine produced faster onset of analgesia when compared with plain prilocaine (P less than 0.01). The onset of anesthesia and recovery from analgesia and anesthesia were not statistically different between the two groups. Clinically, the intensity of anesthesia was better when bicarbonated prilocaine solution was used instead of plain prilocaine. We conclude that bicarbonated prilocaine is better than plain prilocaine during IVRA.

Adult↗
PubMed1982

Advantages of bicarbonate hemodialysis.

Six patients with frequent episodes of symptomatic hypotension during acetate dialysis were treated with bicarbonate dialysis. In all patients blood pressure, heart rate, and arterial acid-base values were measured every 30 minutes during each of the five treatments with acetate dialysis and bicarbonate dialysis. Hemodynamic parameters were measured invasively in all patients during bicarbonate dialysis and in three of them also during acetate dialysis. Additionally, continuous long-time monitoring with electroencephalography was performed during acetate dialysis and bicarbonate dialysis. During acetate dialysis the patients showed a frequent onset of sudden hypotension and arrhythmia with concomitant symptoms of the so-called disequilibrium syndrome, whereas these symptoms were nonexistent in the same patients during bicarbonate dialysis.

Acetates↗
PubMed1986

Calcium carbonate precipitation in bicarbonate hemodialysis.

Calcium carbonate has been observed to precipitate in the fluid pathway of dialysate delivery systems dispensing bicarbonate-containing dialysates. Such precipitation can occlude the fluid pathway, leading to system malfunction and increased maintenance requirements. We show that commercial supplies of sodium bicarbonate are contaminated by trace amounts of sodium carbonate. This contamination may result in immediate precipitation of calcium carbonate on formulation of the dialysate, since bicarbonate-containing dialysates, as formulated, are metastable with respect to calcium carbonate. Sparging of the bicarbonate-containing concentrate with carbon dioxide converts any carbonate to bicarbonate, thus avoiding the formation of precipitates on addition of calcium ions.

Bicarbonates↗
PubMedDate not supplied

Exercise induced alterations in the serum muscle enzymes, erythrocyte potassium and plasma constituents following feed withdrawal or furosemide and sodium bicarbonate administration in the horse.

Six thoroughbreds were used in each of three trials to examine the effect of potassium depletion on exercise-associated muscle damage. Horses were exercised after a control period (Treatment 1), a 72-hour fast (Treatment 2), and furosemide and sodium bicarbonate (Treatment 3). During the preexercise period, feed withdrawal for 72 hours caused decreases in body weight, plasma sodium, chloride, and serum calcium. There were no changes in plasma potassium, erythrocyte potassium, or serum creatine phosphokinase (CK) activity. Furosemide and sodium bicarbonate administration resulted in a decrease in plasma potassium, chloride, serum calcium, and magnesium in the pre-exercise period. Erythrocyte potassium and serum CK activity were unchanged. Body weight initially decreased following furosemide and sodium bicarbonate and then increased upon access to water. In all three treatment groups plasma sodium, potassium, L-lactate, serum calcium, and magnesium were increased immediately following exercise. There was a significant increase (P less than 0.05) in serum CK activity in the furosemide and sodium bicarbonate-treated horses compared to control and withholding feed treatment groups by 30 minutes following exercise. Erythrocyte potassium was decreased immediately following exercise in the furosemide and sodium bicarbonate group but not in the other treatment groups. Potassium depletion may play a role in exercise-induced muscle damage but could not be implicated as the sole cause of the serum CK activity increase in this study.

Animals↗
PubMed2006

Why bicarbonate?

Bicarbonate is a simple single carbon molecule that plays surprisingly important roles in diverse biological processes. Among these are photosynthesis, the Krebs cycle, whole-body and cellular pH regulation, and volume regulation. Since bicarbonate is charged it is not permeable to lipid bilayers. Mammalian membranes thus contain bicarbonate transport proteins to facilitate the specific transmembrane movement of HCO3(-). This review provides a wide-ranging view of the biochemistry of bicarbonate and its membrane transporters, revealing what makes the study of bicarbonate transport such a rewarding activity.

Acid-Base Equilibrium↗
PubMed2001

Long-term ammonium chloride or sodium bicarbonate treatment in two models of polycystic kidney disease.

Administration of ammonium chloride aggravates, while short-term administration of sodium or potassium bicarbonate lessens the development of polycystic kidney disease in Han:SPRD rats. We have conducted studies to determine whether the protection afforded by the administration of sodium bicarbonate is sustained and prevents development of uremia during chronic administration and whether the effects of the administration of ammonium chloride and sodium bicarbonate are also observed in a different model of polycystic kidney disease, the CD1-pcy/pcy mouse. We found that chronic administration of 200 mM sodium bicarbonate to Han:SPRD rats inhibited cystic enlargement and prevented the subsequent development of interstitial inflammation, chronic fibrosis, and uremia. We also found that, while the administration of ammonium chloride has similar effects in Han:SPRD rats and CD1-pcy/pcy mice, the administration of sodium bicarbonate is only protective in the Han:SPRD rats. This probably reflects differences in these models (predominately involvement of proximal tubules in Han:SPRD rats and of collecting ducts and distal tubules in pcy/pcy mice) and the different location and nature of the renal metabolic responses to the administration of acid or alkaline load.

Ammonia↗
PubMed1983

Rapid correction of severe lactic acidosis with massive isotonic bicarbonate infusion and simultaneous ultrafiltration.

Patients with severe lactic acidosis and oliguria who receive large amounts of sodium bicarbonate may develop fluid overload and hyperosmolarity. We infused massive amounts of isotonic sodium bicarbonate and simultaneously removed the excess sodium and water with ultrafiltration if 2 patients with lactic acidosis. The first patient received 1,125 mmol of bicarbonate over 4.5 h with a rise in pH from 7.00 to 7.36 and in HCO3 from 3.5 to 15.7 mmol/l. The second received 968 mmol of bicarbonate over 5.25 h with a rise in pH from 7.00 to 7.27 and in HCO3 from 5.3 to 14 mmol/l. Blood pressure remained stable or rose, electrolytes normalized, excess fluid was removed, and a higher pH was maintained. Isotonic bicarbonate infusion with simultaneous ultrafiltration is a safe and rapid method of correcting the metabolic status of patients with severe lactic acidosis who have not responded to standard therapy.

Acidosis↗
PubMed2006

NBCn1 (slc4a7) mediates the Na+-dependent bicarbonate transport important for regulation of intracellular pH in mouse vascular smooth muscle cells.

The contribution of sodium-dependent bicarbonate transport to intracellular pH (pH(i)) regulation in vascular smooth muscle cells is controversial, partly because the molecular identity of the transporter(s) responsible has not been identified. Here, using the pH-sensitive fluorophore 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF), we show that smooth muscle cells of intact mouse mesenteric, coronary, and cerebral small arteries all display a sodium- and bicarbonate-dependent pH(i) recovery after an NH4+-prepulse. The sodium-dependent bicarbonate flux was largely 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS) sensitive (56% to 91%) and of a magnitude similar to the amiloride-sensitive flux. Additionally, steady-state pH(i) was lower (0.2 to 0.4 pH units magnitude) in all 3 vascular beds when CO2/bicarbonate was omitted. RT-PCR analyses showed that NBCn1 (slc4a7) is the only Na+-dependent bicarbonate transporter of the slc4 family detectable at the mRNA level in all 3 vascular beds investigated. Whole-mount immunolabeling and immunogold electron microscopy confirmed the presence of NBCn1 protein in the sarcolemma of mouse mesenteric small arterial smooth muscle cells. Intact mouse mesenteric small arteries were electropermeated to facilitate transfection with small interfering RNA targeting NBCn1, which resulted in an approximate 43% decrease in the ratio of NBCn1 to glyceraldehyde-3-phosphate dehydrogenase mRNA. After knock-down, we found a decreased steady-state pH(i) (0.21+/-0.08 pH units) as well as a 68+/-10% decrease in the net Na+-dependent, amiloride-insensitive base influx after acid load. Finally, omission of CO2/bicarbonate resulted in a decreased contractile response to norepinephrine after sustained exposure to the agonist, underlining the importance of CO2/bicarbonate for vascular contractility. We conclude that NBCn1 mediates the Na+-dependent bicarbonate transport important for pH(i) regulation in smooth muscle cells of mouse mesenteric, coronary, and cerebral small arteries.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1986

The effects of corn silage dry matter content and sodium bicarbonate addition on nutrient digestion and growth by lambs and calves.

One lamb and three calf trials were conducted to determine if interactions existed between the effects of dry matter (DM) content of corn silage at harvest and sodium bicarbonate supplementation on diet digestibility, nitrogen balance, rate and site of digestion and feedlot performance. Corn plants were harvested from the same field when DM content was approximately 31% (early; E) or 44% (late; L). Sodium bicarbonate (1.2% of DM intake) was added in a completely mixed ration. When lambs were offered diets ad libitum, (trial 1), intakes were greater (P less than .05) for L-silage diets, but apparent digestibilities were similar. Nitrogen balance was greater for sodium bicarbonate-supplemented diets, and was a reflection of greater (P less than .10) DM intakes for these diets. At similar diet DM intakes, N balance was greater for L-silage diets, with no effects measured due to sodium bicarbonate addition. When growing, abomasally cannulated heifers (trial 2) were offered diets 12 times per day, a significant interaction among treatments was measured for total tract and acid detergent fiber (ADF) digestion. Adding bicarbonate to the E-silage diet increased (P less than .05) digestion by 9.1 percentage units (66.4 vs 75.5%) but decreased digestibility of the L-silage diet by 4.2 percentage units (73 vs 68.8%). Grams of ADF apparently digested in the rumen followed the same pattern as for total tract digestion. In trial 3, ruminal rates of liquid and particulate passage and in situ rats of NDF digestion were determined using four rumen-cannulated heifers calves.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1985

Response in two commercial Holstein herds to addition of sodium bicarbonate to alfalfa hay-based diets.

Feeding trials were conducted in two commercial dairy herds to evaluate the addition of .8% sodium bicarbonate to alfalfa hay-based diets. Approximately half of each herd served as controls and the other half was fed the same diet with sodium bicarbonate. A total of 1280 Dairy Herd Improvement Association lactation records were obtained in the two herds during the trials. Cows in herd 1 were milked three times daily and cows in herd 2 were milked twice daily. In herd 1, milk production from control and bicarbonate groups was: first lactation cows, 7491 and 7748 kg/cow; second lactation cows, 8363 and 8791 kg/cow; and third and higher lactation cows, 8713 and 9562 kg/cow. There were no differences in milkfat or solids-not-fat percentages between treatment groups. In herd 2, milk production from control and bicarbonate groups was: first lactation cows, 6800 and 7158 kg/cow; second lactation cows, 8487 and 8082 kg/cow; and third and higher lactation cows, 8807 and 8216 kg/cow. First lactation cows fed sodium bicarbonate had a lower milk fat percentage than controls. There were no other differences in milk fat or solids-not-fat percentages between treatment groups.

Animal Feed↗