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Transport of somatostatin and substance P by human P‐glycoprotein
Author(s) -
Uchiyama-Kokubu Noriko,
Naito Mikihiko,
Nakajima Motowo,
Tsuruo Takashi
Publication year - 2004
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2004.07.084
Subject(s) - somatostatin , p glycoprotein , chemistry , glycoprotein , biochemistry , efflux , substance p , peptide , somatostatin receptor , vesicle , neuropeptide , membrane , biology , endocrinology , receptor , multiple drug resistance , antibiotics
P‐glycoprotein is an efflux pump for a broad spectrum of hydrophobic agents. We found that bioactive peptides including somatostatin and substance P inhibit ATP‐dependent vincristine binding to P‐glycoprotein‐overexpressing K562/ADM membrane vesicles. Some of these bioactive peptides including somatostatin stimulate basal ATPase activity of P‐glycoprotein; in contrast, other peptides including substance P inhibit it. The K562/ADM membrane vesicles showed an ATP‐dependent, osmotically sensitive uptake of somatostatin and substance P, which was inhibited by valspodar, an inhibitor of P‐glycoprotein. These findings suggested that certain bioactive peptides such as somatostatin and substance P directly interact with human P‐glycoprotein as endogenous substrates for P‐glycoprotein‐mediated transport.