Calcium deficiency modifies polyunsaturated fatty acid metabolism in growing rats.
Fatty acid desaturase activities were determined in liver microsomes from calcium-deficient rats and compared to calcium-sufficient ones. The calcium-deprived diet (0.5 g/kg) administered for 60 d caused a 30% inhibition in the delta5 desaturase activity and a 45-55% decrease in delta6 and delta9, respectively, facts that cannot be attributed to a reduction in food intake. In vitro addition of calcium, ethyleneglycol-bis(Beta-aminoethyl ether)N,N-tetraacetic acid, and/or cytosol fractions from control or calcium-deficient rats to microsomes from both groups of animals indicates that the reduced desaturase capacities would be the consequence of an indirect effect of calcium deprivation. The present work shows that the reduced unsaturated fatty acid biosynthesis might be the result of modifications in the physicochemical properties of microsomal membranes. Such changes could also be derived from the inhibition of phospholipase A2 activity induced by calcium deficiency.
Marra
C A
CA
Instituto de Investigaciones Bioquímicas de La Plata, CONICET-UNLP, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Argentina. camarra@atlas.med.unlp.edu.ar
de Alaniz
M J
MJ
D000214:Acyl Coenzyme A / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000008:administration & dosage / Q000172:deficiency* / Q000494:pharmacology; D002136:Calcium, Dietary; D044943:Fatty Acid Desaturases / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D005260:Female; D006128:Growth; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D010741:Phospholipases A / Q000378:metabolism; D054467:Phospholipases A2; D051381:Rats; D017208:Rats, Wistar; D013347:Subcellular Fractions / Q000201:enzymology / Q000378:metabolism
D000214:Acyl Coenzyme A; D002136:Calcium, Dietary; D005231:Fatty Acids, Unsaturated; D044943:Fatty Acid Desaturases; D010741:Phospholipases A; D054467:Phospholipases A2; D002118:Calcium