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Effect of streptozotocin on neurogenic M 2 and M 3 muscarinic receptor‐mediated contractions in mouse urinary bladder
Author(s) -
Pak Kirk J,
Ehlert Frederick J
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.579.6
Subject(s) - muscarinic acetylcholine receptor , streptozotocin , endocrinology , contraction (grammar) , medicine , urinary bladder , chemistry , antagonist , stimulation , acetylcholine , receptor , diabetes mellitus
We studied the effect of streptozotocin (STZ) (125 mg/kg, 20 – 24 weeks prior to experiments) on the contractile roles of M 2 and M 3 muscarinic receptors in the electrical‐field‐stimulated mouse urinary bladder. Electrical‐field stimulation for 5 sec (20 Hz, 0.5 msec, 100 V) elicited contractions that were inhibited by the muscarinic antagonist, N‐methyl scopolamine approximately 50% in urinary bladder from both STZ‐ and vehicle‐treated, wild type mice. In bladder from M 2 KO mice, STZ‐treatment caused a large inhibition of contraction compared to that measured in vehicle‐treated mice. The relaxant effect of isoproterenol on the electrical‐field‐stimulated contraction was similar in wild type urinary bladder from vehicle‐ and STZ‐treated mice. In contrast, the relaxant effect of isoproterenol was much greater in urinary bladder from M 2 KO mice treated with STZ as compared to that from vehicle‐treated mice. Our data show that the contractile role of the M 2 receptor in response to acetylcholine release is increased in urinary bladder following STZ‐treatment and that this mechanism may be critical for sustaining contractile function following the substantial loss of M 3 receptor function induced by STZ. Supported by the MSTP grant, the ARCS Foundation, and NIH grants GM069829, UTN‐37775 and DK081289 .