Cryptosporidium parvum infection in suckling rats: impairment of mucosal permeability and Na(+)-glucose cotransport.
Na(+)-glucose transport and transepithelial permeability were investigated during symptomatic acute cryptosporidiosis in newborn rats. The infection resulted in a significant (P < 0.01) decrease in the ileal short-circuit current and a nonsignificant fall in the transepithelial potential difference and conductance. In glucose-stimulated conditions, the rise in ileal short-circuit current and transepithelial permeability were significantly lower in Cryptosporidium parvum-infected rats than in controls (delta Isc = 3.24 +/- 1.21 microA.cm-2 vs delta Isc = 5.09 +/- 2.23 microA.cm-2 in infected and control animals, respectively; P < 0.001; delta PD = -0.35 +/- 0.13 mV vs delta PD = -0.44 +/- 0.14 mV for infected and control animals, respectively; P < 0.01). Electrical parameters were not affected by addition of the cyclooxygenase inhibitor indomethacin in either Cryptosporidium-infected newborn rats or controls. Horseradish peroxidase and mannitol flux studies demonstrated a significant decrease (P < 0.05) in transepithelial molecular permeability in infected enterocyte rats, HRP flux = 380, range 68-5570 ng.cm-2, and mannitol flux = 1.06, range, 0.34-1.44%.cm-2.min-1, compared with controls rats, HRP flux = 4446 range, 1121-124,363 ng.cm-2, and mannitol flux = 1.99, range, 0.57-5.09%.cm-2.min-1; P < 0.05. These effects could originate from C. parvum-induced alteration of intracellular trafficking of pinocytosis vesicles and therefore account for the decrease in permeability to solute and macromolecules, together with impaired transcellular nutrient transport, in suckling rats.
Capet
C
C
Laboratoire de Biologie Animale et Parasitaire, UFR des Sciences Pharmaceutiques et Biologiques, Paris, France.
Kapel
N
N
Huneau
J F
JF
Magne
D
D
Laikuen
R
R
Tricottet
V
V
Benhamou
Y
Y
Tomé
D
D
Gobert
J G
JG
D000818:Animals; D000833:Animals, Suckling; D003124:Colorimetry; D003457:Cryptosporidiosis / Q000378:metabolism / Q000503:physiopathology*; D016785:Cryptosporidium parvum / Q000502:physiology* / Q000648:ultrastructure; D004195:Disease Models, Animal; D004594:Electrophysiology; D005260:Female; D005947:Glucose / Q000378:metabolism*; D006735:Horseradish Peroxidase / Q000494:pharmacology; D006801:Humans; D007082:Ileum / Q000469:parasitology / Q000503:physiopathology* / Q000648:ultrastructure; D007413:Intestinal Mucosa / Q000469:parasitology / Q000503:physiopathology / Q000648:ultrastructure; D008353:Mannitol / Q000494:pharmacology; D051379:Mice; D008854:Microscopy, Electron; D009004:Monosaccharide Transport Proteins / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D010539:Permeability; D051381:Rats; D017207:Rats, Sprague-Dawley; D012588:Scintillation Counting; D012964:Sodium / Q000378:metabolism*; D013047:Specific Pathogen-Free Organisms