Protein and glucose-induced changes in sodium transport across the pig small intestine.
1. The effect of glucose and of bovine gamma-globulin on short-circuit current and sodium transport was measured using new-born pig ileum before and after suckling.2. Glucose increased the short-circuit current with an apparent K(m) of 1.9 and 19.5 mM for new-born unsuckled and suckled intestines respectively. The V(max) was about 80 muA cm(-2) in each case.3. Bovine gamma-globulin applied to new-born pig ileum caused a 20% increase in sodium chloride influx without change of short-circuit current. The tissue conductance was also greater in the presence of globulin. These effects were not seen in ileum taken from suckled pigs.4. p-Chloromercuriphenyl sulphonic acid (PCMPS) inhibited the globulin induced increase in sodium influx in new-born pig ileum without changing the measured short-circuit current. 0.1 mM-PCMPS also changed the characteristics of the glucose-dependent increase in short-circuit current, so that this response came to resemble that seen in ileum taken from suckled pigs. Dithioerythritol reversed this effect of PCMPS.5. The suckling-dependent difference in results is explained in terms of a change in microvillar function taking place as a consequence of long-term pinocytosis in vivo. The ability of PCMPS to simulate some of these changes suggests that sulphydryl groups might be important regulators of microvillar membrane stability.
D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D001557:Benzenesulfonates / Q000494:pharmacology; D001693:Biological Transport, Active / Q000187:drug effects; D004226:Dithioerythritol / Q000494:pharmacology; D004553:Electric Conductivity; D005947:Glucose / Q000494:pharmacology*; D007082:Ileum / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D007421:Intestine, Small / Q000378:metabolism*; D008628:Mercury / Q000494:pharmacology; D009942:Organometallic Compounds / Q000494:pharmacology; D012964:Sodium / Q000378:metabolism*; D013268:Stimulation, Chemical; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013552:Swine / Q000378:metabolism*; D013997:Time Factors; D005719:gamma-Globulins / Q000037:antagonists & inhibitors / Q000494:pharmacology*
D001557:Benzenesulfonates; D009942:Organometallic Compounds; D013438:Sulfhydryl Compounds; D005719:gamma-Globulins; D004226:Dithioerythritol; D012964:Sodium; D008628:Mercury; D005947:Glucose