Atrial natriuretic peptide (ANP) is known to influence NaCl transport in the medullary thick ascending limbs (MAL), where the largest NaCl reabsorption occurs among distal nephron segments in response to arginine vasopressin (AVP). In the present study, we investigated the effect of ANP on bicarbonate (HCO3 (-)) transport in the MAL using an isolated tubule perfusion technique. The HCO3 (-) con...

With the use of ‘4C-DMO (‘4C-5, 5dimethyl-2,3-oxazolidmnedione), a weak organic acid, we measured the intraerythrocytic hydrogen ion concentration in 16 acidotic and alkalotic patients. Whole blood pH, red cell 2,3diphosphoglycerate, hemoglobin, oxyhemoglobin, plasma pCO2, and plasma bicarbonate were measured simultaneously on heparinized arterial blood. The results show: (1) hydrogen Ion conce...

Puziss, Milton (Fort Detrick, Frederick, Md.) and Mary B. Howard. Studies on immunity in anthrax. XI. Control of cellular permeability by bicarbonate ion in relation to protective antigen elaboration. J. Bacteriol. 85:237-243. 1963.-No elaboration of Bacillus anthracis protective antigen was demonstrated after addition of bicarbonate to cultures incubated 42 hr in a bicarbonate-free medium. Ant...

PHYSIOLOGICAL AND CHEMICAL CONSIDERATIONS Definitions: Van Slyke72 has defined acidosis as a condition in which the bicarbonate of the blood or serum, or, more exactly, the base available for combination with bicarbonate, is diminished. Alkalosis is a condition in which there is in the blood or serum an abnormal excess of bicarbonate, or base available for combination with bicarbonate. These de...

It recently has been shown that whole cell calcium and sodium currents are modulated by CO(2)/HCO(3)(-)-buffered saline. While the bicarbonate ion, but not CO(2), has been proven to modulate calcium currents, this information is lacking for sodium currents. Furthermore, it is not known whether the strength of modulation dependents on the bicarbonate concentration or whether it is an all-or-noth...

PURPOSE OF REVIEW Bicarbonate therapy for severe lactic acidosis remains a controversial therapy. RECENT FINDINGS The most recent 2008 Surviving Sepsis guidelines strongly recommend against the use of bicarbonate in patients with pH at least 7.15, while deferring judgment in more severe acidemia. We review the mechanisms causing lactic acidosis in the critically ill and the scientific rationa...

The present studies examined the mechanism of bicarbonate transport across basolateral membrane vesicles prepared from rabbit renal cortex. Isotopic sodium uptake was stimulated by bicarbonate when compared with gluconate (2.5 nmol/mg protein per 5 s versus 1.4 nmol/mg protein per 5 s), and this process was inhibited by disulfonic stilbenes. Imposition of an interiorpositive potassium diffusion...

In the mosquito midgut, luminal pH regulation and cellular ion transport processes are important for the digestion of food and maintenance of cellular homeostasis. pH regulation in the mosquito gut is affected by the vectorial movement of the principal ions including bicarbonate/carbonate and protons. As in all metazoans, mosquitoes employ the product of aerobic metabolism carbon dioxide in its...

When approaching the analysis of disorders of acid-base balance, physical chemists, physiologists, and clinicians, tend to focus on different aspects of the relevant phenomenology. The physical chemist focuses on a quantitative understanding of proton hydration and aqueous proton transfer reactions that alter the acidity of a given solution. The physiologist focuses on molecular, cellular, and ...

In the tropical fresh water fish, Synbranchus marmoratus, transition from water breathing to air breathing, induced by reduction of oxygen partial pressure (PO2) in the environmental water below 16 mmHg, causes a considerable rise in the arterial partial pressure of carbon dioxide (PCO2), from 5.6 to 26 mmHg on the average (half time of the rise between 2 and 6.5 h). The associated fall in arte...