title: Na+/H+ exchange is present in basolateral membranes from rabbit small intestine.
abstract: Fluorescence quenching of the pH gradient sensitive dye acridine orange and that of the membrane potential sensitive dye Di-S-C3(5) have been studied in purified basolateral membrane vesicles obtained from rabbit small intestine. Basolateral membranes contain an electroneutral, carrier mediated, Na+/H+ exchange activity. They also appear to contain an electrogenic pathway for H+ movement. Based on the comparison of acridine orange fluorescence quenching in the presence of an outwardly directed Na+ gradient and in the presence of known K+ diffusion gradients it can be estimated that at least 50% of the observed proton fluxes are due to the activity of the exchanger. Acridine orange fluorescence recovery measurements have been used to assess the kinetic properties of the exchanger.
mesh_terms: D000165:Acridine Orange; D000818:Animals; D052160:Benzothiazoles; D002232:Carbocyanines; D002352:Carrier Proteins / Q000378:metabolism*; D002451:Cell Compartmentation; D002462:Cell Membrane / Q000378:metabolism; D002474:Cell-Free System; D002712:Chlorides / Q000378:metabolism; D006859:Hydrogen / Q000378:metabolism*; D006878:Hydroxides / Q000378:metabolism; D007421:Intestine, Small / Q000378:metabolism*; D008564:Membrane Potentials; D011817:Rabbits; D012964:Sodium / Q000378:metabolism*; D017923:Sodium-Hydrogen Exchangers
chemical_list: D052160:Benzothiazoles; D002232:Carbocyanines; D002352:Carrier Proteins; D002712:Chlorides; D006878:Hydroxides; D017923:Sodium-Hydrogen Exchangers; C012944:3,3'-dipropyl-2,2'-thiadicarbocyanine; D006859:Hydrogen; D012964:Sodium; D000165:Acridine Orange