کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2007833 | 1066387 | 2006 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Abnormal modulation of cholinergic neurotransmission by endomorphin 1 and endomorphin 2 in isolated bronchus of type 1 diabetic rats Abnormal modulation of cholinergic neurotransmission by endomorphin 1 and endomorphin 2 in isolated bronchus of type 1 diabetic rats](/preview/png/2007833.png)
To assess whether diabetes alters the regulatory effects of μ-opioid receptor (MOR) agonists on the cholinergic bronchoconstriction, we investigated the inhibitory effects of endomorphins (EMs) on the electrical field stimulation (EFS)-induced cholinergic bronchoconstriction in type 1 diabetic rats. At 4 weeks after the onset of diabetes, both the EFS- and exogenous acetylcholine (ACh)-induced bronchoconstriction in diabetes in vitro were greater than those in non-diabetes rats. Furthermore, endomorphin 1 (EM1) and endomorphin 2 (EM2) inhibited the response to EFS in diabetic rat isolated bronchus in a concentration- and frequency-dependent manner, which is in agreement with that in non-diabetes. However, the inhibitory effects of EMs on the EFS-induced bronchoconstriction in diabetes were significantly weaker than those in non-diabetes. Both EM1 and EM2 (1 μM) had no effect on the contractile response to exogenous ACh, indicating a prejunctional effect. Furthermore, the inhibitory effect on the EFS-induced bronchoconstriction was blocked by naloxone (10 μM). Eight weeks after the induction of diabetes, both the EFS- and exogenous ACh-induced bronchoconstrictions in diabetes were further enhanced compared to those in short-time (4 weeks) diabetic rats. Moreover, the inhibitory effects of EMs on the EFS-induced bronchoconstriction were further attenuated. These results suggest that dysfunction of presynaptic inhibitory modulation through opioid receptor by EMs may take place in the bronchus of diabetic rats.
Journal: Peptides - Volume 27, Issue 11, November 2006, Pages 2770–2777