Abstract
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.
Footnotes
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↵1 Recipient of a fellowship from the Ministry of Science and Technology (Spain).
-
This work was supported by Grant PB 97-1123 from the Ministry of Science and Technology (Spain).
- Abbreviations:
- SP
- substance P
- NKB
- neurokinin B
- NKA
- neurokinin A
- NK1R
- tachykinin NK1 receptor
- NK2R
- tachykinin NK2 receptor
- NK3R
- tachykinin NK3 receptor
- RT-PCR
- reverse transcription-polymerase chain reaction
- bp
- base pairs
- GAPDH
- glyceraldehyde-3-phosphate dehydrogenase
- PP1-δ
- protein phosphatase type 1 δ-isoform
- ACh
- acetylcholine
- Received June 7, 2001.
- Accepted August 20, 2001.
- The American Society for Pharmacology and Experimental Therapeutics
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