Effect of delayed gastric emptying on fluoride absorption in the rat.
The rate and site of fluoride (F) absorption were compared in fasted 350 g male rats given 50 micrograms F (as NaF) in either water or a 7.5% pectin solution. Absorption was measured at intervals up to 2 h following gastric intubation. Gastric emptying was measured by inclusion of 14C-PEG in the F solution. The extent of gastric F absorption was derived from rates of gastric emptying (14C-PEG loss) and F loss. Pectin markedly slowed gastric emptying, but by 2 h, more than 90% of the solution had passed into the small intestine in both groups, and F absorption exceeded 90% in both groups. The rate of F absorption was initially much slower in the pectin group than in the group given F in water, and plasma F concentration increased more slowly and reached a lower maximum value. Absorption from the stomach was greater in the pectin group, but still accounted for only approx 25% of total gastrointestinal absorption. The reduced rate of F absorption and slower rise in plasma F concentration accompanying delayed gastric emptying indicate that passage of F into the small intestine is the major factor in rapid F absorption.
Messer
H H
HH
School of Dental Science, University of Melbourne, Australia.
Ophaug
R
R
D000818:Animals; D002250:Carbon Radioisotopes; D005459:Fluorides / Q000097:blood; D005746:Gastric Emptying / Q000187:drug effects; D007408:Intestinal Absorption; D007700:Kinetics; D008297:Male; D010368:Pectins / Q000494:pharmacology; D011092:Polyethylene Glycols / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012969:Sodium Fluoride / Q000378:metabolism*; D013997:Time Factors
D002250:Carbon Radioisotopes; D011092:Polyethylene Glycols; D010368:Pectins; D012969:Sodium Fluoride; D005459:Fluorides