PKA regulation of bicarbonate and lactate movements across rat jejunal plasma membranes. 2004

Maria Novella Orsenigo, and Marisa Tosco, and Umberto Laforenza, and Alide Faelli
Dipartimento di Scienze Biomolecolari e Biotechnologie, Universitá di Milano, Italy. novella.orsenigo@unimi.it

OBJECTIVE 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. CONCLUSIONS PKA activation evokes individual responses that could be coordinated through cellular metabolism.

UI MeSH Term Description Entries
D007583 Jejunum The middle portion of the SMALL INTESTINE, between DUODENUM and ILEUM. It represents about 2/5 of the remaining portion of the small intestine below duodenum. Jejunums
D008297 Male Males
D011919 Rats, Inbred Strains Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding. August Rats,Inbred Rat Strains,Inbred Strain of Rat,Inbred Strain of Rats,Inbred Strains of Rats,Rat, Inbred Strain,August Rat,Inbred Rat Strain,Inbred Strain Rat,Inbred Strain Rats,Inbred Strains Rat,Inbred Strains Rats,Rat Inbred Strain,Rat Inbred Strains,Rat Strain, Inbred,Rat Strains, Inbred,Rat, August,Rat, Inbred Strains,Rats Inbred Strain,Rats Inbred Strains,Rats, August,Rats, Inbred Strain,Strain Rat, Inbred,Strain Rats, Inbred,Strain, Inbred Rat,Strains, Inbred Rat
D002118 Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002462 Cell Membrane The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells. Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D005723 gamma-Glutamyltransferase An enzyme, sometimes called GGT, with a key role in the synthesis and degradation of GLUTATHIONE; (GSH, a tripeptide that protects cells from many toxins). It catalyzes the transfer of the gamma-glutamyl moiety to an acceptor amino acid. GGTP,Glutamyl Transpeptidase,gammaglutamyltransferase,gamma-Glutamyl Transpeptidase,Transpeptidase, Glutamyl,Transpeptidase, gamma-Glutamyl,gamma Glutamyl Transpeptidase,gamma Glutamyltransferase
D000254 Sodium-Potassium-Exchanging ATPase An enzyme that catalyzes the active transport system of sodium and potassium ions across the cell wall. Sodium and potassium ions are closely coupled with membrane ATPase which undergoes phosphorylation and dephosphorylation, thereby providing energy for transport of these ions against concentration gradients. ATPase, Sodium, Potassium,Adenosinetriphosphatase, Sodium, Potassium,Na(+)-K(+)-Exchanging ATPase,Na(+)-K(+)-Transporting ATPase,Potassium Pump,Sodium Pump,Sodium, Potassium ATPase,Sodium, Potassium Adenosinetriphosphatase,Sodium-Potassium Pump,Adenosine Triphosphatase, Sodium, Potassium,Na(+) K(+)-Transporting ATPase,Sodium, Potassium Adenosine Triphosphatase,ATPase Sodium, Potassium,ATPase, Sodium-Potassium-Exchanging,Adenosinetriphosphatase Sodium, Potassium,Pump, Potassium,Pump, Sodium,Pump, Sodium-Potassium,Sodium Potassium Exchanging ATPase,Sodium Potassium Pump
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D001639 Bicarbonates Inorganic salts that contain the -HCO3 radical. They are an important factor in determining the pH of the blood and the concentration of bicarbonate ions is regulated by the kidney. Levels in the blood are an index of the alkali reserve or buffering capacity. Bicarbonate,Bicarbonate Ions,Hydrogen Carbonates,Bicarbonate Ion,Carbonic Acid Ions,Hydrogen Carbonate,Carbonate, Hydrogen,Carbonates, Hydrogen,Ion, Bicarbonate,Ions, Bicarbonate,Ions, Carbonic Acid
D001692 Biological Transport The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments. Transport, Biological,Biologic Transport,Transport, Biologic

Related Publications

Maria Novella Orsenigo, and Marisa Tosco, and Umberto Laforenza, and Alide Faelli
April 1993, The American journal of physiology,
Maria Novella Orsenigo, and Marisa Tosco, and Umberto Laforenza, and Alide Faelli
April 1969, Experimental eye research,
Maria Novella Orsenigo, and Marisa Tosco, and Umberto Laforenza, and Alide Faelli
December 1984, The Journal of biological chemistry,
Maria Novella Orsenigo, and Marisa Tosco, and Umberto Laforenza, and Alide Faelli
November 2003, American journal of physiology. Gastrointestinal and liver physiology,
Maria Novella Orsenigo, and Marisa Tosco, and Umberto Laforenza, and Alide Faelli
April 1976, Kidney international,
Maria Novella Orsenigo, and Marisa Tosco, and Umberto Laforenza, and Alide Faelli
June 2010, Chemical communications (Cambridge, England),
Maria Novella Orsenigo, and Marisa Tosco, and Umberto Laforenza, and Alide Faelli
May 1990, The Journal of physiology,
Maria Novella Orsenigo, and Marisa Tosco, and Umberto Laforenza, and Alide Faelli
September 1988, The Biochemical journal,
Maria Novella Orsenigo, and Marisa Tosco, and Umberto Laforenza, and Alide Faelli
October 1969, The Journal of physiology,
Maria Novella Orsenigo, and Marisa Tosco, and Umberto Laforenza, and Alide Faelli
August 1993, European journal of clinical investigation,
Copied contents to your clipboard!