Transport of nutrients and electrolytes across the intestinal wall in pigs

TRIENNIAL GROWTH SYMPOSIUM: Effects of polymeric carbohydrates on growth and development in pigs1

“…Consequently, end products of a-amylase digestion are maltose, maltotriose, and a-limit dextrins. Because there is no integral transport process in the intestinal enterocyte that can accommodate anything larger than free glucose (Moran, 1985;Gray, 1992), the oligosaccharides have to be degraded further to glucose by surface oligosaccharidases, which are large glycoprotein components of the intestinal surface brush-border membrane (Breves et al, 2007(Breves et al, , 2010. Glycoamylase (i.e., amyloglucosidase, maltase-glucoamylase) is capable of removing single a-1,4-linked glucose residues sequentially from the nonreducing end, but is blocked when an a-1.4-liiiked glucose becomes located at the terminal end of the saccharide.…”

“…The final glucose product can then be transported by the specific glucose carrier, an integrated brush-border glycoprotein expressed only in the small intestine and with a high affinity for the monosaccharide. The actual driving force for uphill transport of ghicose into the enterocyte is provided by the Na-K ATPase, which pumps the intracellular Na"^ across the basolateral membrane (Breves et al, 2007(Breves et al, , 2010. Glucose probably diffuses from the basolateral (i.e., serosal) surface to the capillaries of the villous core and further to the portal vein.…”

Traditional Chinese medicine decoction enhances growth performance and intestinal glucose absorption in heat stressed pigs by up-regulating the expressions of SGLT1 and GLUT2 mRNA

“…GLUT2 transports glucose and fructose out of the enterocyte across the basolateral membrane (Jane et al, 2003;Breves et al, 2007). The expressions of SGLT1 and GLUT2 were crucial to the absorption and uptake of glucose in the small intestine, the elevation of SGLT1 activity resulted in the up-regulation of glucose uptake (Rodriguez et al, 2004).…”

“…Glucose absorption in the small intestine depends on two types of transport mechanisms. One is glucose transporter 2 (GLUT2), which serves as a facilitated diffusion system through lipid bilayers, and the other is Na + -dependent glucose transporter 1 (SGLT1), which mediates Na + /glucose co-transport function both in kidney and intestine as a secondary active transporter (Breves et al, 2007). The expression of glucose transport such as SGLT1 and GLUT2 was crucial to the absorption and transport competence of glucose in the small intestine (Rodriguez et al, 2004).…”

Transport of valine across the small intestinal epithelium in pigs fed different valine levels and Bacillus subtilis

“…Thereafter, 0, 5, 10 or 20 mmol L‐Val/L (chamber concentration) was added to the Ringer solution at the mucosal side of two chambers, while at the same time, 0, 5, 10 and 20 mmol mannitol/L (chamber concentration), respectively, were added to the Ringer solution at the serosal side to keep osmolarity equal on the two sides. The Val transport was estimated as the increase in Isc (ΔIsc Val ) achieved 5 min after Val addition as Val is cotransported with Na + (Breves, Kock, & Schroder, ; Broer, ). To measure the net Val transport, samples of the mucosal and serosal Ringer solutions (200 μl) were collected at 0, 30, 60 and 90 min after addition of Val and mannitol (0 min), and the sampled Ringer solution volumes were replaced immediately.…”