A Role for Tachykinins in Female Mouse and Rat Reproductive Function1

Tachykinins may be involved in reproduction. A reverse tran-scription-polymerase chain reaction assay was used to analyze the expression of tachykinins and tachykinin receptors in differ-ent types of reproductive cells from mice. The preprotachykinin (PPT) genes, PPT-A, PPT-B and PPT-C, that encode substance P/ neurokinin A, neurokinin B, and hemokinin-1, respectively, and the genes that encode the tachykinin NK1, NK2, and NK3 recep-tors were all expressed, at different levels, in the uterus of su-perovulated, unfertilized mice. The mRNA of neprilysin (NEP), the main enzyme involved in tachykinin metabolism, was also expressed in the uterus. Isolated cumulus granulosa cells ex-pressed PPT-A, PPT-B, PPT-C, and NEP and low levels of the tachykinin NK1 and NK2 receptors. Mouse oocytes expressed PPT-A and-B mRNA transcripts. A low expression of the thre