Cristina Porta

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Transepithelial fluid transport was measured gravimetrically in rabbit gallbladder (and net Na+ transport was calculated from it), at 27°C, in HCO 3 − -free bathing media containing 10−4 m acetazolamide. Whereas luminal 10−4 m bumetanide or 10−4 m 4-acetamido-4′-iso-thiocyanostilbene-2,2′-disulfonate (SITS) did not affect fluid absorption, 25 mm SCN−(More)
Latex beads coated with secretory immunoglobulin (IgA) instilled into mouse intestinal loops are taken up by M cells present in Peyer's patch follicle-associated epithelial tissue. Bead adsorption and uptake is greater at the edge compared with the apex of follicle domes. Coating beads with bovine serum albumin (BSA) causes a fourfold reduction in(More)
Hydrochlorothiazide (HCTZ) was shown to inhibit the transepithelial NaCl transport and the apical Na+-Cl− symport and to depolarize the apical membrane potential in the rabbit gallbladder epithelium. The depolarization was likely related to the opening of a Cl− conductance. To better understand whether an apical Cl− leak is involved in the mechanism of(More)
M cells are specialized structures in the Peyer's patch follicle-associated epithelium capable of taking up bacteria, viruses and other pathogens for later presentation to the gut-associated lymphoid tissue. The present work studies how coating microspheres with different proteins affects their ability to be taken up by M cells under near physiological(More)
In the rabbit gallbladder epithelium, hydrochlorothiazide (HCTZ) was shown to inhibit the transepithelial NaCl transport and the apical Na+-Cl− symport, to depolarize the apical membrane potential and to enhance the cell-to-lumen Cl− backflux (radiochemically measured), this increase being SITS-sensitive. To better investigate the causes of the(More)
An active absorption of polypeptides (elcatonin = CCT; adrenocorticotropic hormone) had been previously observed in the nasal respiratory mucosa of the rabbit. Its saturation kinetics and the parallel absence of a net transfer of other non-polypeptidic organic markers excluded the involvement of a simple pinocytosis. This absorption has been now better(More)
In rabbit nasal mucosa, free polypeptides and polypeptide-coated nanospheres are actively absorbed by the M cells present in specialized areas of the epithelium. Because polypeptide-coated nanosphere transport was abolished in the presence of free polypeptides, free polypeptides and polypeptide-coated nanospheres are shown here to compete. Fluxes of(More)
Molecular evidence for Na+-glucose cotransporter (SGLT1) in rabbit pleural mesothelium has been recently provided, confirming earlier functional findings on solute-coupled liquid absorption from rabbit pleural space. In this research we checked whether SGLT1 is also expressed in pleural mesothelium of species with thick visceral pleura, which receives blood(More)
Because oxidative stress is a component of gastrointestinal injury, we investigated the effect of H(2)O(2) on transintestinal transport using isolated rat jejunum incubated in vitro. Millimolar concentrations of H(2)O(2) inhibited all the tested parameters without inducing any cytotoxic effect. Electrophysiological experiments indicated that H(2)O(2)(More)