We hypothesized that in vitro knock-down of the previously cloned genes of prostaglandin synthases will result in a reduction of synthesis, and thus secretion of their respective products, i.e., prostaglandin (PG) E-2 or PGF(2 alpha). For this purpose, we designed short hairpin RNA (shRNA)-encoding constructs to knock down porcine mPGES-1 and PGFS (also named as AKR1CL1 in GenBank) and used them to transfect swine kidney SK-6 cells. Knocking down PGFS or mPGES-1 transcripts resulted in at least 50% inhibition of protein expression of each respective enzyme, as well as a reduction in the production of their respective prostaglandin, PGF(2 alpha), or PGE(2). These results confirmed the identities of PGFS and mPGES-1. Moreover, they illustrate a unique opportunity to use the gene knock-down constructs in primary endometrial cells in order to study their biological roles in the porcine endometrium, particularly during the establishment of pregnancy. (C) 2014 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.