Plasma hydrogen ions

In 1928 James Gamble and Monroe Mclver of Harvard, then in the midst of their pioneer work that stimulated the study of electrolytes in pediatrics, found that the total chloride concentration of cat gastric juice obtained from the body of the stomach was constant and almost equal to the fixed base, that is, all the cations remaining after incineration of the sample of the animal s plasma. Hydrogen ion concentration plus fixed base in the juice varied reciprocally, but their sum was equal to that of chloride. In secretions from the antrum that contained no acid, the fixed base and the sum of chloride and bicarbonate were each nearly equal to the fixed base of plasma (Fig. 1-7). These data imply that gastric secretions are nearly... 

Plasma hydrogen ion and bicarbonate concentrations Typical normal values [H" "] 40nM, [HCO3 ] 24mM. 

The pH scale is widely used in biological applications because hydrogen ion concentrations in biological fluids are very low, about 10 M or 0.0000001 M, a value more easily represented as pH 7. The pH of blood plasma, for example, is 7.4 or 0.00000004 M H. Certain disease conditions may lower the plasma pH level to 6.8 or less, a situation that may result in death. At pH 6.8, the H concentration is 0.00000016 M, four times greater than at pH 7.4. 

Fig.2 shows the infrared absorption spectrum of the tin oxide film. In order to analyze the molecular structure of the deposited film, we deposited the tin oxide film on a KBr disc with thickness of 1 mm and diameter of 13 mm. Various peaks formed by surface reaction are observed including O-H stretching mode at 3400 cm, C=C stretching mode at 1648 cm, and Sn02 vibration mode at 530 cm. The formation of sp structure with graphite-like is due to ion bombardment with hydrogen ions at the surface and plasma polymerization of methyl group with sp -CHa. 

The carbon dioxide produced during cellular metabolism diffuses out of the cells and into the plasma. It then continues to diffuse down its concentration gradient into the red blood cells. Within these cells, the enzyme carbonic anhydrase (CA) facilitates combination of carbon dioxide and water to form carbonic acid (H2C03). The carbonic acid then dissociates into hydrogen ion (H+) and bicarbonate ion (HC03). 

Hydrogen ion secretion. Hydrogen ions are secreted in the proximal tubule, distal tubule, and collecting duct. The secretion of hydrogen ions is an important mechanism in acid-base balance. The normal pH of the arterial blood is 7.4. When the plasma becomes acidic, H+ ion secretion increases and when it becomes alkalotic, H+-ion secretion is reduced. 

To summarize this section, the electrochemical hydrogenation experiments performed to date have yielded substantial penetration of low levels of hydrogen, but show promise for practical utilization despite temperature limitations and complications such as material removal. As with plasma and ion beam methods, the surface of this subject has barely been scratched. 

Acetazolamide is an aromatic sulfonamide used as a carbonic anhydrase inhibitor. It facilitates production of alkahne urine with an elevated biocarbonate, sodium, and potassium ion concentrations. By inhibiting carbonic anhydrase, the drug suppresses reabsorption of sodium ions in exchange for hydrogen ions, increases reflux of bicarbonate and sodium ions and reduces reflux of chloride ions. During this process, chloride ions are kept in the kidneys to cover of insufficiency of bicarbonate ions, and for keeping an ion balance. Electrolytic contents of fluid secreted by the kidneys in patients taking carbonic anhydrase inhibitors are characterized by elevated levels of sodium, potassium, and bicarbonate ions and a moderate increase in water level. Urine becomes basic, and the concentration of bicarbonate in the plasma is reduced. 

Pharmacology Increases plasma bicarbonate buffers excess hydrogen ion concentration raises blood pH reverses the clinical manifestations of acidosis. 

Pharmacokinetics Sodium bicarbonate in water dissociates to provide sodium and bicarbonate ions. Sodium is the principal cation of extracellular fluid. Bicarbonate is a normal constituent of body fluids and normal plasma level ranges from 24 to 31 mEq/L. Plasma concentration is regulated by the kidney. Bicarbonate anion is considered labile because, at a proper concentration of hydrogen ion, it may be converted to carbonic acid, then to its volatile form, carbon dioxide, excreted by lungs. Normally, a ratio of 1 20 (carbonic acid bicarbonate) is present in extracellular fluid. In a healthy adult with normal kidney function, almost all the glomerular filtered bicarbonate ion is reabsorbed less than 1% is excreted in urine. 

Aldosterone and other steroids with mineralocorticoid properties promote the reabsorption of sodium from the distal part of the distal convoluted tubule and from the cortical collecting renal tubules, loosely coupled to the excretion of potassium and hydrogen ion. Sodium reabsorption in the sweat and salivary glands, gastrointestinal mucosa, and across cell membranes in general is also increased. Excessive levels of aldosterone produced by tumors or overdosage with synthetic mineralocorticoids lead to hypokalemia, metabolic alkalosis, increased plasma volume, and hypertension. 

The kidney regulates the acid-base balance of the body by control over resorption of sodium ions, which may exchange for hydrogen ions in the kidney tubule. Since most dietaries are of acid-ash, the urine is usually more acid than the original plasma filtrate and much of the phosphate excreted is thus changed to the acid monosodium salt, Within the range of normal variability, with an alkaline ash diet, the urine may become alkaline, and in extreme instances, some sodium bicarbonate may be excreted. 

Carbon dioxide (C02) and hydrogen ions (H+) both have negative effects on oxygen binding also. These effects are closely related and together are known as the Bohr effect. A substantial amount of C02 generated by decarboxylation reactions of intermediary metabolism diffuses from cells through interstitial fluid into the blood plasma, with... 

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