Background/Aims: Evidence was previously given that the mechanisms involved in bicarbonate and lactate movements across rat jejunal enterocyte are modulated by PKC and Ca2+/CaM. Aim of this study was to investigate the possible role of PKA on bicarbonate and lactate transports. Methods: Enzymatic assays in isolated plasma membranes were performed. Moreover membrane vesicles, transiently opened and resealed, were treated with a phosphorylating solution (leading to PKA activation) and were used after that to perform uptake studies. Results: Enzymatic assays give evidence for the presence of PKA in plasma membranes from rat jejunum. Uptake experiments suggest that PKA stimulates the two systems that accomplish basolateral HCO3- efflux from the enterocyte, namely Cl-/ HCO3- exchanger and HCO3- conductance, without affecting HCO3- influx from the lumen mediated by Na+/H+ exchanger activity. Moreover basolateral H+/lactate symporter is stimulated by PKA, as well as the brush border isoform of Na+-glucose cotransporter SGLT1. Conclusion: PKA activation evokes individual responses that could be coordinated through cellular metabolism.
PKA regulation of bicarbonate and lactate movements across rat jejunal plasma membranes / M.N. Orsenigo, M. Tosco, U. Laforenza, A. Faelli. - In: CELLULAR PHYSIOLOGY AND BIOCHEMISTRY. - ISSN 1015-8987. - 14:1-2(2004), pp. 77-90.
|Titolo:||PKA regulation of bicarbonate and lactate movements across rat jejunal plasma membranes|
ORSENIGO, MARIA NOVELLA (Primo)
TOSCO, MARISA GIUSEPPINA DOROTEA (Secondo)
FAELLI, ALIDE (Ultimo)
|Parole Chiave:||Bicarbonate transport; Lactate transport; PKA; Rat jejunum|
|Settore Scientifico Disciplinare:||Settore BIO/09 - Fisiologia|
|Data di pubblicazione:||2004|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1159/000076929|
|Appare nelle tipologie:||01 - Articolo su periodico|