Decreased passage of the nonapeptide dDAVP over the intestinal epithelium during development in the young rat.
The nonapeptide 1-deamino-cysteine-8-D-arginine vasopressin (dDAVP) was gavage-fed together with cow's milk whey protein to young, developing rats. The transepithelial passage of dDAVP in the gastrointestinal (GI) tract was assessed by a specific RIA as immunoreactive levels in blood serum extracts and as urinary excretion of dDAVP 0.5-8 h after feeding. In 14-day-old rats the passage of dDAVP was higher than in 30-day-old rats, since the 14-day-old rats had significantly higher serum levels (5-10 times) 0.5-2 h after feeding and a urinary excretion approaching 0.15% of the administered amount after 8 h. In the 30-day-old rats urinary excretion increased up to 0.05% after 2 h and then levelled off. It was also clear that 30-day-old rats had a slower transfer to and faster elimination from serum than 14-day-old rats. dDAVP appeared to be passed over the GI tract mucosa independently of intestinal proteolysis since feeding it to 30-day-old rats together with the proteinase inhibitors, soya-bean trypsin inhibitor and pepstatin did not influence the serum or urinary levels. Thus, dDAVP was taken up from the GI tract into the blood circulation and excreted in the urine of young rats. The decrease in the passage of dDAVP found around weaning appears to be related to developmental processes affecting the permeability of the intestinal epithelium rather than intestinal proteolysis.
Folkesson
H G
HG
Department of Zoophysiology, University of Lund, Sweden.
Weström
B R
BR
Lundin
S
S
Karlsson
B W
BW
D000818:Animals; D003894:Deamino Arginine Vasopressin / Q000378:metabolism*; D004848:Epithelium / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000166:cytology / Q000254:growth & development; D051381:Rats; D011919:Rats, Inbred Strains
D003894:Deamino Arginine Vasopressin