Apolipoprotein synthesis in human fetal intestine: regulation by epidermal growth factor.
In this investigation, human fetal intestine (17-20 wk) was used to study the synthesis of apolipoproteins (apo) A-I and B and its modulation by epidermal growth factor. Cultured jejunal explants were incubated with [3%S]-methionine, homogenized, immunoprecipitated and subjected to gel analysis. Radioactivity was detected mostly in apo A-I and, to a lesser extent, in both apo B-48 and apo B-100. However, apo B-48 was always the predominant form. The addition of EGF (100 ng/ml) resulted in a simultaneous decrease in apo B-100 synthesis and increase in apo B-48 production without a marked effect on apo A-I. Moreover, the incubation of jejunal explants with [14C] oleic acid documented the ability of fetal intestine to produce chylomicrons, VLDL, LDL and HDL. Therefore, the human fetal intestine has an efficient lipoprotein-lipid transport system and EGF is able to modulate levels of both apo B species as well as lipoprotein fractions.
Levy
E
E
Department of Nutrition, Hôpital Ste-Justine, Université de Montréal, Québec, Canada.
Thibault
L
L
Delvin
E
E
Ménard
D
D
D000029:Abortion, Legal; D016632:Apolipoprotein A-I / Q000096:biosynthesis*; D001055:Apolipoproteins B / Q000096:biosynthesis*; D001483:Base Sequence; D002914:Chylomicrons / Q000096:biosynthesis; D003062:Codon; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D005260:Female; D005333:Fetus; D005865:Gestational Age; D006801:Humans; D007583:Jejunum / Q000187:drug effects / Q000378:metabolism*; D008074:Lipoproteins / Q000096:biosynthesis* / Q000302:isolation & purification; D008075:Lipoproteins, HDL / Q000096:biosynthesis; D008077:Lipoproteins, LDL / Q000096:biosynthesis; D008079:Lipoproteins, VLDL / Q000096:biosynthesis; D008715:Methionine / Q000378:metabolism; D009924:Organ Culture Techniques; D011247:Pregnancy; D013462:Sulfur Radioisotopes
D016632:Apolipoprotein A-I; D001055:Apolipoproteins B; D002914:Chylomicrons; D003062:Codon; D008074:Lipoproteins; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D008079:Lipoproteins, VLDL; D013462:Sulfur Radioisotopes; D004815:Epidermal Growth Factor; D008715:Methionine