Gastrointestinal and Pancreatic Hormones in the Human Fetus and Mother at 18–21 Weeks of Gestation

Abstract

Several gastrointestinal hormones appear to play an important developmental role in the newborn, particularly in preterm neonates. Although the cells producing these peptides develop towards the end of the first trimester, fetal secretion of these regulatory peptides has not hitherto been demonstrated. Using samples collected by fetoscopy at 19–21 weeks of gestation we have measured concentrations of several gastrointestinal and pancreatic hormones. Maternal venous and amniotic fluid hormone concentrations were measured simultaneously. Concentrations of the pancreatic hormones, insulin, glucagon and pancreatic polypeptide (PP) were similar in fetal and maternal blood. Gastrin and motilin were present in the fetal circulation but at about 30% (p < 0.05) and 60% (p < 0.01) of the maternal levels, respectively. In contrast, enteroglucagon concentrations were more than twofold higher in the fetal circulation compared with maternal levels (p < 0.05). Concentrations of gastric inhibitory polypeptide (GIP) in fetal blood were higher than levels in maternal blood but not significantly. Concentrations of GIP (p < 0.001) were higher in the amniotic fluid than the fetal circulation. Gastrin and glucagon levels were similar in amniotic fluid and fetal blood. In contrast, PP and motilin were present in amniotic fluid, but at lower concentrations than in fetal blood. Enteroglucagon was not detectable in amniotic fluid. In conclusion, several alimentary hormones are secreted in the fetus at midterm. Since these peptides have trophic, secretory and motor effects on the gut, it is likely that these regulatory peptides are involved in the functional development of the fetal intestine.

Developmental Regulation of Intestinal Epithelial Hydrolase Activity in Human Fetal Jejunal Xenografts Maintained in Severe-Combined Immunodeficient Mice

“…High surges of glucocorticoids have the ability to elicit precocious maturation in a number of experimental animal models (5,43). Signals derived from luminal amniotic fluid may also contribute to the development of enzyme activities in utero (44), possibly mediated by specific growth factors. Organ culture studies of human fetal intestine in defined tissue culture medium have demonstrated differential effects of hydrocortisone, insulin, and epidermal growth factor in regulating hydrolase expression, apolipoprotein and lipoprotein secretion, and cellular proliferation (45)(46)(47)(48)(49).…”

Leptin and Ob-Rb Receptor Isoform in the Human Digestive Tract during Fetal Development

“…Leptin is also presumed to play a role in the developmental process of fetus (5, 10). Components of human amniotic fluid such as growth factors and hormones are important mediators of the functional gastrointestinal development (38). They can be transported across the fetal epithelium by endocytic process (39).…”

Inverse association between maternal 25OHD level and cord GLP-1/GIP concentrations

“…Both GLP-1 and GIP are gut-derived incretin hormones that stimulate insulin and suppress glucagon secretion, inhibit gastric emptying, and reduce appetite and food intake (28). Placental transfer of both incretin hormones might be considered negligible (29), and both hormones are secreted in the fetus (30)(31)(32)(33). Eating provokes the secretion of multiple gastrointestinal hormones involved in the regulation of gut motility, secretion of gastric acid and pancreatic enzymes, gall bladder contraction, and nutrient absorption as well as insulin secretion.…”