RT Journal Article SR Electronic T1 Increase in Neurokinin B Expression and in Tachykinin NK3 Receptor-Mediated Response and Expression in the Rat Uterus with Age JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 934 OP 938 VO 299 IS 3 A1 Cristina G. Cintado A1 Francisco M. Pinto A1 Philippe Devillier A1 Angel Merida A1 M. Luz Candenas YR 2001 UL http://jpet.aspetjournals.org/content/299/3/934.abstract AB We analyzed tachykinin NK3 receptor (NK3R) gene expression by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) in uteri from young (3-month-old) and old (30-month-old) rats. In addition, we characterized the expression of the preprotachykinin-B (TAC-3) gene, which encodes neurokinin B (NKB), the preferred endogenous agonist of NK3R. Compared with young rats, NK3R messenger RNA (mRNA) levels were about 45-fold higher in uteri from old animals. TAC-3 mRNA was expressed in the rat uterus, and its levels were about 2.5-fold higher in old than in young rats. The contractile effect of the selective tachykinin NK3R agonist [MePhe7]-NKB in uteri from young and old animals was investigated by using conventional organ bath technique. A marked correlation was observed between the magnitude of the contraction elicited by [MePhe7]-NKB and the level of expression determined by RT-PCR for the NK3R. These observations are consistent with a role for the NKB/NK3R ligand-receptor pair in regulating uterine functions and support the existence of a link between estrogen and the NK3R/NKB activation pathway. The American Society for Pharmacology and Experimental Therapeutics