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Activation of L‐arginine transport by protein kinase C in rabbit, rat and mouse alveolar macrophages
Author(s) -
Racké Kurt,
Hey Claudia,
Mössner Jutta,
Hammermann Rainer,
Stichnote Christina,
Wessler Ignaz
Publication year - 1998
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1111/j.1469-7793.1998.813bg.x
Subject(s) - arginine , cycloheximide , staurosporine , protein kinase c , phorbol , leucine , microbiology and biotechnology , sodium , chemistry , chelerythrine , stimulation , biochemistry , protein kinase a , amino acid , endocrinology , biology , kinase , protein biosynthesis , organic chemistry
1 The role of protein kinase C in controlling L‐arginine transport in alveolar macrophages was investigated. 2 L‐[ 3 H]Arginine uptake in rabbit alveolar macrophages declined by 80 % after 20 h in culture. 4β‐Phorbol 12‐myristate 13‐acetate (PMA), but not 4α‐phorbol 12‐myristate 13‐acetate (α‐PMA), present during 20 h culture, enhanced L‐[ 3 H]arginine uptake more than 10‐fold. Staurosporine and chelerythrine opposed this effect. 3 L‐[ 3 H]Arginine uptake was saturable and blockable by L‐lysine. After PMA treatment V max was increased more than 5‐fold and K m was reduced from 0.65 to 0.32 mM. 4 Time course experiments showed that PMA increased L‐[ 3 H]arginine uptake almost maximally within 2 h. This short‐term effect was not affected by cycloheximide or actinomycin D. 5 L‐[ 3 H]Arginine uptake and its stimulation by PMA was also observed in sodium‐free medium. 6 L‐Leucine (0.1 mM) inhibited L‐[ 3 H]arginine uptake by 50 % in sodium‐containing medium, but not in sodium‐free medium. At 1 mM, L‐leucine caused significant inhibition in sodium‐free medium also. L‐Leucine showed similar effects on PMA‐treated cells. 7 N‐ Ethylmaleimide (200 μ m , 10 min) reduced L‐[ 3 H]arginine uptake by 70 % in control cells, but had no effect on PMA‐treated (20 or 2 h) cells. 8 In alveolar macrophages, multiple transport systems are involved in L‐arginine uptake, which is markedly stimulated by protein kinase C, probably by modulation of the activity of already expressed cationic amino acid transporters.