Premium
Protein Kinase C Regulation of Rat Jejunal Transport Systems: Mechanisms Involved in Lactate Movement
Author(s) -
Tosco Marisa,
Orsenigo Maria Novella,
Gastaldi Giulia,
Faelli Alide
Publication year - 2002
Publication title -
experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0958-0670
DOI - 10.1113/eph8702465
Subject(s) - protein kinase c , staurosporine , chelerythrine , symporter , cotransporter , membrane transport , chemistry , biochemistry , glucose transporter , biology , microbiology and biotechnology , kinase , transporter , endocrinology , membrane , sodium , insulin , organic chemistry , gene
We examined whether protein kinase C (PKC) modulates the transport systems involved in lactate movements across the plasma membranes of rat jejunum. In vitro phosphorylated membrane vesicles were used to perform uptake studies, the results of which suggested that PKC activation exerts an inhibitory effect on basolateral H + ‐lactate symport, as well as on apical Na + ‐glucose cotransport. The specificity of the response to PKC was confirmed by using staurosporine, chelerythrine or 4‐α‐PMA. Experiments performed using the whole tissue incubated in vitro confirmed the reduction of lactate transport elicited by PKC and gave evidence for an associated inhibition of fluid transport. Na + ,K + ‐ATPase activity seems to be unaffected by the kinase and inhibited by Ca 2+ . Taken together, our results suggest that the overall action of PKC results from the simultananeous modulation of multiple pathways, targeted to a reduction of both lactate and bicarbonate transports without altering cell pH homeostasis.