Muscarinic receptor subtypes in the bisected vas deferens of the rat

• 1.1. The nature of muscarinic receptor subtypes in the isolated prostatic and epididymal segments of the vas deferens of the rat were studied.
• 2.2. Presynaptic receptors were characterized in segments under neurogenic transmural stimulation; postsynaptic receptors in segments without stimulation.
• 3.3. The present work suggests that the potency of ACh required to activate muscarinic receptors is higher in the prostatic than in the epididymal segment.
• 4.4. McN-A-343 was only able to induce dose-dependent contractions in the prostatic segment.
• 5.5. The pA₂ value for 4-DAMP suggests that in the prostatic segment the postsynaptical ACh receptors seem to be pharmacologically similar to the ACh-M₃ subtype.
• 6.6. Antagonism of the presynaptic ACh receptor subtype by pirenzepine supports the evidence that these receptors belong to the ACh-M₁ subtype.