Cystometric findings in mice lacking muscarinic M2 or M3 receptors

• Purpose: The physiological importance of muscarinic M-3 and M-2 receptors for bladder function was investigated in vivo using mice lacking M-3 or M-2 receptors and littermate WT controls. Materials and Methods: Unanesthetized mice of each sex underwent continuous cystometry before and after administration of atropine (1 mg/kg(-1)). Results: Male M-3 knockout (KO) mice had longer voiding intervals, and larger micturition volumes and bladder capacity than M-2 KO or WT males. There was no significant difference in any cystometric parameters between male M-2 KO and WT mice. In females M-3 KO and M-2 KO mice had longer voiding intervals and larger micturition volumes than WT animals. Atropine had marked inhibitory effects on voiding efficacy in WT and M-2 KO mice but it had no effect on any cystometric parameters in M-3 KO mice. Conclusions: The current results confirm that M-3 receptor is the principal muscarinic receptor subtype responsible for bladder contraction and the role of M-2 receptors is of minor importance. Functional impairments found in M-3 KO mice were milder than those elicited by acute blockade of muscarinic receptors by atropine in WT mice, suggesting that noncholinergic mechanisms can compensate for a chronic loss of M-3 receptors.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Urologi och njurmedicin (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Urology and Nephrology (hsv//eng)

Nyckelord

receptors

bladder

purinergic

muscarinic

atropine

mice

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art (ämneskategori)

ref (ämneskategori)