Hormonal regulation of chicken intestinal NHE and SGLT-1 activities.
The effects of aldosterone and arginine vasotocin (AVT) on intestinal Na(+)/H(+) exchange (NHE) and Na(+)-sugar cotransport (SGLT-1) activities have been investigated using brush-border membrane vesicles isolated from Hubbard chicken small and large intestines, and they were compared with those induced by either Na(+) depletion or dehydration. Na(+) depletion was induced by feeding the chickens with either a low- or a high-Na(+) diet for either 0.5, 1, 2, 4, or 8 days. Ileal and colonic NHE2 activity increased with the duration of the Na(+) depletion, whereas that of intestinal SGLT-1 decreased, reaching a plateau after 2 days of treatment. Three-hour incubation of the intestine with aldosterone produced the same effects on NHE activity as does Na(+) depletion, without altering SGLT-1 activity. However, 3-h incubation of the intestine with AVT increased intestinal SGLT-1 activity, without affecting intestinal NHE activity. It is concluded that aldosterone regulates apical ileal and colonic NHE2 activity, whereas that of SGLT-1 is regulated by AVT.
De La Horra
M C
MC
Departamento Fisiología y Biología Animal, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain.
Cano
M
M
Peral
M J
MJ
Calonge
M L
ML
Ilundáin
A A
AA
D000450:Aldosterone / Q000097:blood / Q000494:pharmacology*; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002645:Chickens; D003106:Colon / Q000378:metabolism; D004039:Diet, Sodium-Restricted; D005947:Glucose / Q000378:metabolism; D007082:Ileum / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000187:drug effects / Q000648:ultrastructure; D007583:Jejunum / Q000378:metabolism; D007700:Kinetics; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008871:Microvilli / Q000187:drug effects / Q000378:metabolism; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism; D012982:Sodium, Dietary / Q000008:administration & dosage; D051269:Sodium-Glucose Transporter 1; D017923:Sodium-Hydrogen Exchangers / Q000378:metabolism*; D014668:Vasotocin / Q000494:pharmacology*
D008562:Membrane Glycoproteins; D009004:Monosaccharide Transport Proteins; D012982:Sodium, Dietary; D051269:Sodium-Glucose Transporter 1; D017923:Sodium-Hydrogen Exchangers; D000450:Aldosterone; D012964:Sodium; D005947:Glucose; D014668:Vasotocin