Developmental sialic acid modifications in rat organs.
The changes in expression of sialic acids in Sprague-Dawley rats in the prenatal and early postnatal time period have been examined in multiple organs, both visceral and non-visceral. In all organs examined, there is a dramatic increase in both N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc) shortly after birth. The bulk of the sialic acid is present in the ganglioside fraction in all tissues examined. As total amounts of sialic acid present in gangliosides decrease, the proportion present in the low molecular weight cytosolic fraction increases. A curious observation is that Neu5Ac hydroxylase activity is present at the time of the increase in sialic acid, but its activity does not correlate with Neu5Gc expression after the early postnatal period. This implies that Neu5Gc expression has another level of regulation besides CMP-Neu5Ac hydroxylase activity.
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Department of Medicine, University of California, San Diego, VA Medical Center 92161.
D000375:Aging / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D005333:Fetus / Q000378:metabolism*; D005732:Gangliosides / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism; D006899:Mixed Function Oxygenases / Q000378:metabolism; D019158:N-Acetylneuraminic Acid; D009438:Neuraminic Acids / Q000378:metabolism; D009928:Organ Specificity; D051381:Rats; D011919:Rats, Inbred Strains; D012794:Sialic Acids / Q000378:metabolism*
D005732:Gangliosides; D006023:Glycoproteins; D009438:Neuraminic Acids; D012794:Sialic Acids; C032592:N-glycolylneuraminic acid; D006899:Mixed Function Oxygenases; C074383:CMPacetylneuraminate monooxygenase; D019158:N-Acetylneuraminic Acid