TY - JOUR
T1 - Refined Estimation of Kinetic Parameters of the Na+/H+ Antiport in Human Fibroblasts and Platelets
AU - Gardner, Jeffrey P.
AU - Tokudome, Goro
AU - Tomonari, Haruo
AU - Aladjem, Mordechai
AU - Cragoe, Edward
AU - Aviv, Abraham
PY - 1990/6
Y1 - 1990/6
N2 - A technique is presented to estimate the initial rates of Na+-dependent alkal-inization of acidified human fibroblasts and platelets and assess the kinetics of the Na+/ H+ antiport in these cells. Cytosolic pH (pHi) exhibits an exponential recovery following cellular acidification. Thus, the length of the time interval selected to monitor changes in pHi (ΔpHi) is critical to estimating the kinetics of the Na+/H+ antiport. We compared kinetic parameters of the Na+/H+ antiport, using computed and observed changes in ΔpHi, for arbitrarily selected time intervals following Na+-dependent activation. In both cells, significant increases in both the [Na+] for half-maximal activation (K 0.5) and maximal velocities (V max) were observed as ΔpHi was decreased. We conclude that kinetic parameters derived from initial rate determinations enable a more accurate characterization of the Na+/H+ antiport.
AB - A technique is presented to estimate the initial rates of Na+-dependent alkal-inization of acidified human fibroblasts and platelets and assess the kinetics of the Na+/ H+ antiport in these cells. Cytosolic pH (pHi) exhibits an exponential recovery following cellular acidification. Thus, the length of the time interval selected to monitor changes in pHi (ΔpHi) is critical to estimating the kinetics of the Na+/H+ antiport. We compared kinetic parameters of the Na+/H+ antiport, using computed and observed changes in ΔpHi, for arbitrarily selected time intervals following Na+-dependent activation. In both cells, significant increases in both the [Na+] for half-maximal activation (K 0.5) and maximal velocities (V max) were observed as ΔpHi was decreased. We conclude that kinetic parameters derived from initial rate determinations enable a more accurate characterization of the Na+/H+ antiport.
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U2 - 10.3181/00379727-194-43073
DO - 10.3181/00379727-194-43073
M3 - Article
C2 - 2161542
AN - SCOPUS:0025369432
SN - 0037-9727
VL - 194
SP - 165
EP - 171
JO - Proceedings of the Society for Experimental Biology and Medicine
JF - Proceedings of the Society for Experimental Biology and Medicine
IS - 2
ER -