Effect of phosphorus supply on phosphate uptake and alkaline phosphatase activity in Rhizobia

1984 ◽  
Vol 140 (2-3) ◽  
pp. 281-286 ◽  
Author(s):  
J. B. Smart ◽  
M. J. Dilworth ◽  
A. D. Robson
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Phosphate Uptake

Intestinal phosphate transport and alkaline phosphatase activity in the chick

1981 ◽  
Vol 240 (4) ◽  
pp. E384-E390 ◽  
Author(s):  
S. J. Birge ◽  
R. C. Avioli
Keyword(s):  
Alkaline Phosphatase ◽  
Epithelial Cells ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Phosphate Uptake ◽  
Intestinal Epithelial Cells ◽  
Phosphate Transport ◽  
Intestinal Epithelial ◽  
Ph Optimum

The initial rates of phosphate accumulation by isolated chick intestinal epithelial cells have been examined. At high concentrations of phosphate (1.5 mM), phosphate uptake is relatively independent of sodium and demonstrates a pH optimum of 8.0. At pH 8.0, 56% of the uptake is dependent on the presence of Ca in the uptake medium compared to 28% at pH 6.8. Membranes prepared from these same intestinal epithelial cells contain a Ca-dependent phosphatase that can be distinguished from the more abundant Mg-dependent alkaline phosphatase. The Ca-dependent phosphatase has a pH optimum between 8.5 and 9.0 and, compared to the Mg-dependent activity, is more readily inactivated at 58 degrees C and is relatively resistant to L-phenylalanine inhibition but more sensitive to ethane-1-hydroxy-1,1-diphosphonate (EHDP). Both activities are distributed in a constant proportion between the brush border and basal lateral membranes and at various segments along the intestine. Vitamin D in vivo and 25-hydroxyvitamin D [25(OH)D] in vitro stimulated both activities. In vitro, utilizing the isolated intestinal cells, the stimulation of phosphate uptake paralleled the increase in Ca-dependent alkaline phosphatase activity. The role of alkaline phosphatase in intestinal phosphate transport is discussed.

Phosphate uptake in chemostat cultures of Escherichia coli K-12 subjected to periodic β-glycerophosphate pulsing: a system for assaying alkaline phosphatase

1979 ◽  
Vol 25 (5) ◽  
pp. 560-564 ◽  
Author(s):  
J. C. Francis ◽  
S. L. King
Keyword(s):  
Escherichia Coli ◽  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Phosphate Uptake ◽  
Density Fluctuations ◽  
Population Doubling ◽  
Population Doubling Time ◽  
Chemostat Cultures ◽  
K 12

Limiting concentrations of β-glycerophosphate were pulsed into chemostat cultures of Escherichia coli K-12 at intervals equal to the population doubling time. The resultant culture density fluctuations are interpreted in terms of inorganic phosphate uptake which, in this system, is a function of alkaline phosphatase activity. Information concerning in vivo alkaline phosphatase activity at suboptimal (acidic) pH with very low concentrations of substrate (β-glycerophosphate) is obtained from kinetic analysis of uptake data.

LEUCOCYTE METABOLISM IN PREGNANCY

1960 ◽  
Vol XXXV (IV) ◽  
pp. 575-584 ◽  
Author(s):  
C. Borel ◽  
J. Frei ◽  
A. Vannotti
Keyword(s):  
Alkaline Phosphatase ◽  
Oxygen Consumption ◽  
Pregnant Women ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Lactate Production ◽  
Glucose Consumption ◽  
In Pregnancy

ABSTRACT Enzymatic studies, on leucocytes of pregnant women, show an increase of the alkaline phosphatase activity and a decrease of the glucose consumption and lactate production, as well as of proteolysis. The oxygen consumption, with succinate as substrate, does not vary.

Sign in / Sign up

Export Citation Format

Share Document