Thioglycolate-elicited rat macrophages exhibit alterations in incorporation and oxidation of fatty acids.

Incorporation and oxidation of fatty acids (FA) were investigated in resident and thioglycolate-elicited (TG-elicited) rat macrophages (Mphi). Both cell types presented a time-dependent incorporation of [14C]-labeled palmitic acid (PA), oleic acid (OA), linoleic acid (LA), and arachidonic acid (AA) up to 6 h. The total amount of [14C]-FA incorporated by resident Mphi after 6 h was: AA > PA = LA > OA. TG-elicited cells presented a 50% reduction in the incorporation of LA, PA, and AA, whereas that of OA remained unchanged as compared to resident Mphi. The FA were oxidized by resident Mphi as follows: LA > OA > PA > AA. TG elicitation promoted a reduction of 42% in LA oxidation and a marked increase in AA oxidation (280%). The increased oxidation of AA in TG-elicited cells may account for the lower production of prostaglandins in Mphi under these conditions. The full significance of these findings for Mphi function, however, remains to be examined.