Prenatal development of gastrointestinal function in the pig and the effects of fetal esophageal obstruction.
Maturation of the fetal gastrointestinal tract (GIT) is influenced by both luminal stimuli (e.g. swallowed fluid) and hormonal factors (e.g. endogenous cortisol release). The aims of the present study were 1) to investigate GIT growth and maturation during the last 20% of gestation in pigs (term = 114 +/- 2 d), and 2) to investigate the effect of esophageal ligation, to prevent fetal swallowing, at 80% to 91% gestation. In normal fetuses, marked increases occurred during late gestation in body weight (+95%), relative intestinal weight (+79%, g kg(-1) body weight), activity of some digestive enzymes (1.5- to 10-fold), and absorption of glucose and intact proteins (3- to 6-fold). Fetuses with ligated esophagi had lowered body weight (-20%), reduced intestinal weight (-43%), aminopeptidase A activity (-24%), and glucose absorption (-27%), while lactase, sucrase, and dipeptidylpeptidase IV activities were increased (+40-50%), compared with sham-operated fetuses (all p < 0.05). Other parameters of GIT function remained unchanged by esophageal obstruction (absorption of amino acids and immunoglobulin, activity of chymosin, amylase, trypsin, chymotrypsin, maltase, aminopeptidase N -- all expressed per gram GIT tissue). Ligated fetuses had elevated cortisol levels, which is known to stimulate fetal GIT maturation. We conclude that the rapid development of GIT function in late gestation is diminished by esophageal obstruction, mainly due to slower GIT growth and not inhibition of normal functional development of enterocytes.
Division of Nutrition, Royal Veterinary and Agricultural University, 13 Bulowsvej, DK-1870 Frederiksberg C, Denmark. psa@kvl.dk
Per T
PT
Sangild
Mette
M
Schmidt
Jan
J
Elnif
Charlotte R
CR
Björnvad
Björn R
BR
Weström
Randal K
RK
Buddington
D000818:Animals; D000831:Animals, Newborn; D001835:Body Weight; D004064:Digestive System / Q000196:embryology* / Q000201:enzymology / Q000254:growth & development; D004068:Digestive System Physiological Phenomena; D004947:Esophagus / Q000196:embryology* / Q000502:physiology; D005260:Female; D005333:Fetus; D005865:Gestational Age; D006801:Humans; D007408:Intestinal Absorption; D008026:Ligation; D009929:Organ Size; D011247:Pregnancy; D013552:Swine / Q000196:embryology*