The effects of 17 alpha-ethynyloestradiol and of acute inflammation on the plasma concentration of rat alpha 1-acid glycoprotein and on the induction of its hepatic mRNA.
We measured the serum concentration of alpha 1-acid glycoprotein (alpha 1-AGP) and we evaluated the content of its hepatic mRNA in rats after 17 alpha-ethynyloestradiol treatment or after turpentine-induced acute inflammation, or after both treatments performed simultaneously. We have also studied the affinity of serum alpha 1-AGP for concanavalin A under these conditions. Both types of stimuli induce a marked retention of the glycoprotein on free concanavalin A. The serum concentration of alpha 1-AGP is increased about 14-fold compared with that in control rats when a single pharmacological dose (50 micrograms) or multiple injections of 17 alpha-ethynyloestradiol are administered. This increase is greater in turpentine-oil-injected rats (about 21-fold) and reaches a maximum (about 32-fold) in rats injected with 17 alpha-ethynyloestradiol plus turpentine oil; this increase in alpha 1-AGP corresponds to the addition of the effects of the two inducing agents. Similar changes are also observed either in the alpha 1-AGP mRNA content as estimated by using an alpha 1-AGP-specific cDNA probe, or in the amount of translatable alpha 1-AGP mRNA. The results indicate that: after a high dose of 17 alpha-ethynyloestradiol and after acute inflammation, the increase of the alpha 1-AGP serum concentration is due to an accumulation of the alpha 1-AGP mRNA; different mechanisms and/or pathways are probably involved in regulating the synthesis of alpha 1-AGP under various stimuli; 17 alpha-ethynyloestradiol as well as acute inflammation seem to control the glycosylation process of alpha 1-AGP in an identical manner.
D000818:Animals; D004997:Ethinyl Estradiol / Q000494:pharmacology*; D007122:Immunoelectrophoresis; D007249:Inflammation / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009961:Orosomucoid / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D014176:Protein Biosynthesis / Q000187:drug effects; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D009961:Orosomucoid; D012333:RNA, Messenger; D004997:Ethinyl Estradiol