Regulation of sialylation of intestinal brush-border enzymes and of sialyltransferase activity in organ cultures by dexamethasone.
To investigate the direct effect of glucocorticoids on sialylation of intestinal brush-border hydrolases, explants of fetal and suckling rat intestine were maintained in serum-free or serum-containing organ culture with or without dexamethasone (Dx). Glucoamylase and dipeptidyl peptidase IV developed in organ culture from 18-day-old fetuses persisted in highly sialylated forms for 8 days irrespective of Dx presence, parallel in vivo development leading to less sialylated forms at the age of 6 days. In postnatal cultures the Dx-stimulated glucoamylase appeared in a new highly sialylated form never seen after the hormone application in vivo. These findings are in agreement with the elevation of bound sialyltransferase (ST) of cultured intestine in protein-free media. In serum-containing medium Dx stimulated the formation and release of soluble ST into the culture medium.
Kolínská
J
J
Institute of Physiology, Czechoslovak Academy of Sciences, Prague.
Baudysová
M
M
Zákostelecká
M
M
Kraml
J
J
Kadlecová
L
L
D000818:Animals; D003470:Culture Media; D003907:Dexamethasone / Q000494:pharmacology*; D006867:Hydrolases / Q000378:metabolism; D007422:Intestines / Q000187:drug effects* / Q000196:embryology / Q000648:ultrastructure; D007525:Isoelectric Focusing; D008871:Microvilli / Q000187:drug effects / Q000201:enzymology; D009924:Organ Culture Techniques; D051381:Rats; D011919:Rats, Inbred Strains; D012799:Sialyltransferases / Q000187:drug effects*; D012995:Solubility
D003470:Culture Media; D003907:Dexamethasone; D012799:Sialyltransferases; D006867:Hydrolases