Treatment with prostaglandin F2a increases expression of prostaglandin synthase-2 in the rat corpus luteum

Recent studies indicate that the corpus luteum (CL) may be a source of prostaglandin F-2alpha (PGF(2alpha)) for regression. We investigated expression of mRNA and protein for prostaglandin G/H synthase (PGHS) in the CL of immature superovulated rats following administration of PGF(2alpha). We observed an increase in mRNA for PGHS-2, the induced isoforrn, at 1 h and protein at 8 and 24 h after treatment. One hour after PGF(2alpha), there was also a progressive decrease in plasma progesterone concentration. There were no changes, however, in expression of PGHS-1, the constitutive isoform, over the 24 h sampling period. These results indicate that PGHS-2 increases following PGF(2alpha) treatment and that expression of this enzyme in the rat CL may contribute to the luteolytic mechanism. (C) 2002 Elsevier Science Inc. All rights reserved.