Fetal intestinal microvilli in human amniotic fluid.
The intestinal microvilli of fetal origin in human amniotic fluid were purified by Ca2+ precipitation of contaminating organelles followed by differential centrifugation of microvillar membranes. In the purified preparation, the specific activity of the microvillar marker-enzymes maltase and sucrase increased about 77-fold over that in cell-free amniotic fluid. Significant contamination of the purified preparation by endoplasmic reticulum (microsomes) and lysosomes was ruled out on the basis of a low content of the marker enzymes glucose-6-phosphatase (microsomes) and acid phosphatase (lysosomes). Amniotic fluid microvilli contain typical enzymes of the fetal intestine including maltase, sucrase, trehalase, alkaline phosphatase and gamma-glutamyltransferase, and their morphology by electron microscopy resembles that of vesiculated intestinal microvilli. Prenatal detection of genetic diseases due to a deficiency of a protein expressed in these membranes or associated to abnormal microvilli seems feasible.
D000135:Acid Phosphatase / Q000378:metabolism; D000469:Alkaline Phosphatase / Q000378:metabolism; D000653:Amniotic Fluid / Q000166:cytology* / Q000201:enzymology; D002458:Cell Fractionation; D004186:Disaccharidases / Q000378:metabolism; D005260:Female; D005952:Glucose-6-Phosphatase / Q000378:metabolism; D006801:Humans; D007413:Intestinal Mucosa / Q000648:ultrastructure*; D008854:Microscopy, Electron; D008871:Microvilli / Q000201:enzymology; D011247:Pregnancy
D000469:Alkaline Phosphatase; D000135:Acid Phosphatase; D005952:Glucose-6-Phosphatase; D004186:Disaccharidases