Aim: The identity of muscarinic acetylcholine receptors (mAchR) involved in cholinergic-mediated contraction of the guinea pig gallbladder has been a matter of debate. Different groups have suggested the involvement of M1, M2, M3, or M4 receptor subtypes in the contraction of this tissue. The objective of this study was to identify the mAchR subtypes expressed in the guinea pig gallbladder by RT-PCR. Methods: Total RNA prepared from frozen guinea pig gallbladder tissue was amplified by using specific primers for the M1M4 receptor subtypes. Results: M2, M3, and M4 transcripts were detected in the following rank order: M4 > M2 > M3. We were unable to demonstrate the expression of the M1 receptor subtype in this tissue. Conclusions: Our results are in agreement with our previous binding and functional data.
Bibliographical noteFunding Information:
This work was funded by National Institutes of Health USA (FIRCA grants RO 3 TW00615, NS 25743 and NS 30454) and Marmara University Research Fund (Grant HEA-083/131200).
- Guinea pig gallbladder
- Muscarinic receptors