Development of Na+ transport in the chicken colon.
To evaluate the developmental changes in colonic Na+ transport, Na, K-ATPase activity and the sensitivity of the short-circuit current to amiloride were investigated. The amiloride-sensitive short-circuit current which represents the electrogenic, amiloride-sensitive Na+ transport through Na+ channels, was not present in chicken embryos but rose significantly after hatching in chicks which were kept on a low-salt diet. Amiloride-sensitive short-circuit current increased gradually but the plateau was not reached during the first 15 days of life. Drinking of 0.9% NaCl totally inhibited the induction of amiloride-sensitive Na+ transport. Na+, K(+)-ATPase activity increased during development but was not influenced by changes in salt intake. Na+ transport in chicken colon therefore undergoes profound developmental changes. The increase of Na+ transport reflects not only the adaptation of colonocytes to low salt intake but also the maturation of Na+ absorption in colon. The possible role of aldosterone in the adaptation to low-salt intake is discussed.
Pácha
J
J
Institute of Physiology, Czech Academy of Sciences, Prague.
D000584:Amiloride / Q000494:pharmacology*; D000818:Animals; D002642:Chick Embryo; D002645:Chickens / Q000254:growth & development / Q000378:metabolism*; D003106:Colon / Q000187:drug effects / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D017136:Ion Transport / Q000187:drug effects; D012964:Sodium / Q000378:metabolism*; D012982:Sodium, Dietary / Q000008:administration & dosage / Q000494:pharmacology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000187:drug effects / Q000378:metabolism*
D012982:Sodium, Dietary; D000584:Amiloride; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase