TY - JOUR
T1 - Calcium-induced inhibition of taurine transport in brush-border membrane vesicles from rabbit small intestine
AU - Miyamoto, Ysei
AU - Kulanthaivel, Palaniappan
AU - Ganapathy, Vadivel
AU - Whitford, Gary M.
AU - Leibach, Frederick H.
N1 - Funding Information:
This work was supported in part by NIH Grant DK 28389. The authors thank Mrs. Ida O. Thomas for expert secretarial assistance. This is contribution number 1239 from the Department of Cell and Molecular Biology.
PY - 1990/12/14
Y1 - 1990/12/14
N2 - The influence of Ca2+ on the activity of the taurine transport system was investigated in rabbit small intestinal brush-border membrane vesicles. Preincubation of the brush-border membrane vesicles with Ca2+ prepared by the Mg2+-aggregation method markedly decreased the NaCl gradient-dependent uptake of taurine in these vesicles. Uptake of glucose and alanine, both dependent on a Na+ gradient, were also decreased by Ca2+-treatment, but their reduction was very small compared with that of taurine uptake. The inhibitory effect of Ca2+ was dose- and time-dependent. The inhibition was reduced by the presence of ethylene glycol-bis(β-amino ethyl ether)-N,N,N′-N′-tetraacetic acid during treatment of the membrane vesicles with Ca2+. Neomycin partially protected the taurine transporter activity from the Ca2+-induced inhibition, but indomethacin did not. 5-Nitro-2-(3-phenylpropylamino)benzoate, a Cl--channel blocker, did not increase taurine uptake in the Ca2+-treated membrane vesicles. It is concluded that the Ca2+-induced inhibition of taurine uptake in rabbit intestinal brush-border membrane vesicles is not due to accelerated dissipation of the ion gradient driving forces across the membrane but rather to a direct effect on the transporter, most likely mediated by the activation of the membrane-bound phospholipase C.
AB - The influence of Ca2+ on the activity of the taurine transport system was investigated in rabbit small intestinal brush-border membrane vesicles. Preincubation of the brush-border membrane vesicles with Ca2+ prepared by the Mg2+-aggregation method markedly decreased the NaCl gradient-dependent uptake of taurine in these vesicles. Uptake of glucose and alanine, both dependent on a Na+ gradient, were also decreased by Ca2+-treatment, but their reduction was very small compared with that of taurine uptake. The inhibitory effect of Ca2+ was dose- and time-dependent. The inhibition was reduced by the presence of ethylene glycol-bis(β-amino ethyl ether)-N,N,N′-N′-tetraacetic acid during treatment of the membrane vesicles with Ca2+. Neomycin partially protected the taurine transporter activity from the Ca2+-induced inhibition, but indomethacin did not. 5-Nitro-2-(3-phenylpropylamino)benzoate, a Cl--channel blocker, did not increase taurine uptake in the Ca2+-treated membrane vesicles. It is concluded that the Ca2+-induced inhibition of taurine uptake in rabbit intestinal brush-border membrane vesicles is not due to accelerated dissipation of the ion gradient driving forces across the membrane but rather to a direct effect on the transporter, most likely mediated by the activation of the membrane-bound phospholipase C.
KW - (Rabbit)
KW - Brush border
KW - Calcium ion induced inhibition
KW - Phospholipase C
KW - Small intestine
KW - Taurine transport
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U2 - 10.1016/0005-2736(90)90294-X
DO - 10.1016/0005-2736(90)90294-X
M3 - Article
C2 - 2124507
AN - SCOPUS:0025245705
SN - 0005-2736
VL - 1030
SP - 189
EP - 194
JO - BBA - Biomembranes
JF - BBA - Biomembranes
IS - 2
ER -