Inhibition of arachidonate biosynthesis in hepatoma tissue culture cells by 11-deoxycorticosterone-induced factor.
In this work it was demonstrated that the incubation of hepatoma cultured cells (HTC 7288 c) with 11-deoxycorticosterone (DOC) ranging from 0 to 10(-4) M concentration provoked a dose-dependent inhibition in the conversion of [1-14C] eicosatrienoic acid to arachidonic acid. This steroid also produced an increase in the uptake of exogenous 20:3 (n-6) acid. The depressive effect evoked by DOC on delta 5 desaturating activity was reflected on the fatty acid composition changes of the hepatoma cells. The delta 5 desaturase activity was inhibited by a soluble factor that would be induced by the hormone and that was present in the cytosol fraction from DOC-treated cells, corresponding to a low molecular mass below 25 kDa. Presently we report that an 11-beta-OH group on the steroid molecule is not an essential requirement for the production of a delta 5 desaturase inhibitory factor.
Marra
C A
CA
Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CONICET-UNLP, Facultad de Ciencias Médicas, Argentina.
de Alaniz
M J
MJ
D015126:8,11,14-Eicosatrienoic Acid / Q000378:metabolism*; D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000302:isolation & purification / Q000378:metabolism*; D003600:Cytosol / Q000201:enzymology; D003900:Desoxycorticosterone / Q000494:pharmacology*; D044943:Fatty Acid Desaturases / Q000378:metabolism*; D005227:Fatty Acids / Q000032:analysis; D008114:Liver Neoplasms, Experimental / Q000378:metabolism*; D008862:Microsomes, Liver / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D001095:Arachidonic Acids; D005227:Fatty Acids; D016718:Arachidonic Acid; D003900:Desoxycorticosterone; D044943:Fatty Acid Desaturases; D015126:8,11,14-Eicosatrienoic Acid