A Preliminary Report on the Influence of Hydrogen-Ion Concentration upon the Longevity of Strongylus vulgaris (Looss, 1900) In vitro

1938 ◽  
Vol 24 (5) ◽  
pp. 469 ◽  
Author(s):  
J. H. Whitlock ◽  
E. E. Leasure
Keyword(s):  
Preliminary Report ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Strongylus Vulgaris

Effect of norepinephrine on myocardial intracellular hydrogen ion concentration

1975 ◽  
Vol 229 (2) ◽  
pp. 344-349 ◽  
Author(s):  
KM Riegle ◽  
RL Clancy
Keyword(s):  
Metabolic Acidosis ◽  
Respiratory Acidosis ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Beta Blockade ◽  
Hydrogen Ion Concentration ◽  
Rat Hearts ◽  
Buffer Value

The effect of norepinephrine (NE) on the intracellular hydrogen ion concentration [H+]i of isolated rat hearts perfused with a modified Krebs-Henseleit solution (SHS) was determined. The [H+]i was calculated with the [14C]-dimethyloxazolidinedione method. Respiratory or metabolic acidosis was produced by equilibrating the KHS with 20% C02 or decreasing the [HC03-] of the KHS, respectively. Three types of experiments were carried out: 1) beta blockade--MJ 1999 (Sotalol) was added to the KHS; 2) control--no pharmacological treatment; and 3) NE-norepinephrine was added to the KHS. The effective CO2 buffer values (delta[HC03-]i/deltapHi) during respiratory acidosis were: beta blockade, 11; control, 35; and NE, 84. The production of metabolic acidosis resulted in the following [H+]i changes: beta blockade, 52 mM; control, 60 nM; and NE 7 nM. These results suggest that NE markedly attenuates the changes in [H+]i accompanying respiratory and metabolic acidosis and may account in part for previous observations that the effective C02 buffer value of cardiac muscle in vivo is greater than that in vitro.

Effect of glucose and inosine triphosphate on seasonal variation of gastric acid production in Rana pipiens

1959 ◽  
Vol 196 (5) ◽  
pp. 975-978 ◽  
Author(s):  
Sherwin Mizell
Keyword(s):  
Seasonal Variation ◽  
Gastric Acid ◽  
Acid Production ◽  
Rana Pipiens ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Total Chloride ◽  
Effect Of Glucose

The production of acid in vitro by the gastric mucosa of 375 Rana pipiens was studied over a period of 13 months. The frogs were kept at 21°C and histamine was used to induce secretion. Four conditions were studied: a) control, no substrate added to the nutrient solution; b) 10 mm glucose added; c) 0.6 µm inosine triphosphate (ITP) added and d) 10 mm glucose and 0.6 µm ITP added. For each mucosa the change in hydrogen ion concentration (ΔpH), titrable acidity and total chloride produced were measured. The results indicate that the seasonal variation in gastric acid production is due, in part, to a variation in the availability of substrate normally present.

scholarly journals STUDIES ON THE PHYSICAL AND CHEMICAL PROPERTIES OF THE VIRUS OF FOOT-AND-MOUTH DISEASE

1927 ◽  
Vol 45 (5) ◽  
pp. 833-848 ◽  
Author(s):  
Peter K. Olitsky ◽  
Louis Boëz
Keyword(s):  
Active Agent ◽  
Chemical Properties ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Basic Medium ◽  
Hydrogen Ion Concentration ◽  
Foot And Mouth

No multiplication of the virus in vitro was observed. We have found, however, that the optimum conditions necessary for the preservation of the virus in artificial media are as follows: The hydrogen ion concentration of the medium should be 7.5 to 7.6, not only at the beginning, but, and more important, at the conclusion of the period of observation. A strict anaerobic atmosphere is also favorable, as is a temperature below 37°C. A semisolid structure of the medium appears to be advantageous and this can be effected by the use of ¼th per cent agar or 10 per cent gelatin. Of the two, the gelatin is more desirable, and of the latter the most effective material is gelatin from which the impurities have been most thoroughly removed, namely the gelatin employed by Loeb for his isoelectric determinations. This material is best adjusted to the proper hydrogen ion concentration (7.5–7.6) with potassium hydroxide and not with buffer phosphate. Gelatin is the simplest of protein media available and its employment is in keeping with the principle we have found that the requirements for life of the virus of foot-and-mouth disease are of the simplest. The addition of organic or complex protein substances, such as dextrose, broth, serum, lipoids, etc., to a simple basic medium interferes with the effectiveness of the latter. It is thus not surprising that we were unable to confirm the cultural results of Frosch and Dahmen for neither their medium nor its components or their method satisfies the essential conditions necessary to maintain artificially the life of the virus. Furthermore, from the standpoint of technique it was found necessary when comparing 2 or more media for their value in preserving the incitant, to employ all of them in a parallel experiment with the same sample of virus, for the factors of potency of the active agent, contamination, and changes in hydrogen ion concentration, if variable, may give rise to faulty interpretations. Moreover, activity in 3 successive subplants may be regarded as mere preservation but not multiplication of the virus. Finally, we discuss the status of the virus from the point of view of its fluid or particulate, and its animate or inanimate, characters.

Effect of hydrogen ion concentration on aldosterone secretion by isolated perfused canine adrenal glands

1986 ◽  
Vol 110 (2) ◽  
pp. 293-301 ◽  
Author(s):  
K. J. Radke ◽  
R. E. Taylor ◽  
E. G. Schneider
Keyword(s):  
Angiotensin Ii ◽  
Adrenal Glands ◽  
Recovery Period ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Aldosterone Secretion ◽  
Acid Base ◽  
Hydrogen Ion Concentration ◽  
Secretory Rate

ABSTRACT The direct effects of changes in extracellular hydrogen ion (H+) concentration on aldosterone secretion under basal, angiotensin II- and potassium-stimulated conditions were studied in isolated, perfused canine adrenal glands. Changes in extracellular H+ concentration were induced by altering either the partial pressure of CO2 (pCO2) or the HCO3− concentration of the perfusate. Acid-base disturbances had a more pronounced effect on aldosterone secretion under stimulated than under basal conditions. Increasing H+ concentration enhanced angiotensin II- and potassium-stimulated aldosterone secretion, whereas decreasing H+ concentration markedly inhibited the secretory response to these stimuli. Because changes in H+ concentration, whether produced by varying extracellular pCO2 or extracellular HCO3− concentration, had similar effects on angiotensin II-stimulated aldosterone secretion, the data suggest that H+ concentration per se is the important determinant of the aldosterone secretory rate. Interestingly, during the immediate recovery period from pCO2-induced alkalosis under both angiotensin II- and potassium-stimulated conditions, aldosterone secretion always returned to a value significantly higher than that obtained just before alkalosis. The results of this study demonstrate that changes in extracellular H+ concentration influence the rate of aldosterone secretion, possibly via changes in intracellular pH, by a direct action on the canine adrenal gland. Therefore, when evaluating the control of aldosterone secretion, the acid-base status of the whole animal or of in-vitro adrenal tissue must be considered. J. Endocr. (1986) 110, 293–301

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